Navigating women with congenital heart disease during pregnancy: Management strategies and future directions

Abstract

Women with adult congenital heart disease (CHD) face unique challenges during pregnancy, as gestational cardiovascular (CV) and hemodynamic changes can exacerbate underlying cardiac conditions. While these adaptations are well tolerated in women with structurally and functionally normal hearts, they pose significant risks for those with adult CHD (ACHD), whether repaired, palliated, or with residual defects. Maternal CHD is associated with an increased risk of adverse CV events, including stroke, heart failure, arrhythmias, and thromboembolic complications during pregnancy and the peripartum period. Effective management requires a multidisciplinary team, including cardiologists, perinatologists, anesthesiologists, and other skilled care providers. Risk stratification tools such as the modified World Health Organization classification, CARPREG II, and ZAHARA scores are useful for predicting maternal and fetal outcomes and guiding clinical decision-making. Preconception counseling plays a critical role in assessing individual risks, optimizing cardiac function, and educating patients about potential complications. Future research should prioritize innovative therapies, including targeted pharmacological agents and minimally invasive interventions, alongside improved screening methods to identify high-risk patients before symptomatic disease manifests. This review synthesizes current literature on managing pregnant women with ACHD, highlights gaps in clinical practice, and explores future directions to enhance care. Addressing these challenges is essential to improving maternal and fetal outcomes and ensuring comprehensive, patient-centered care throughout the reproductive journey.

Key Words: Congenital heart disease; Pregnancy; Women with congenital heart disease; Contraception; Postpartum care; Maternal & fetal outcomes

Core Tip: Managing adult congenital heart disease (ACHD) in pregnancy requires a multidisciplinary approach. Preconception counseling, risk stratification with the modified World Health Organization classification, and tailored monitoring optimize maternal and fetal outcomes. Hemodynamic changes can worsen ACHD complications, necessitating specialized cardio-obstetric team care. Individualized delivery plans, vigilant postpartum surveillance, and post-delivery contraception counseling are essential. Advances in imaging and interventions improve outcomes, but high-risk cases demand tertiary center expertise to address cardiac decompensation, arrhythmia, or heart failure, ensuring safe pregnancy management. Future directions emphasize AI-driven risk prediction to further enhance outcomes.

INTRODUCTION

Advances in managing congenital heart disease (CHD) have led to an increased number of women with adult CHD (ACHD) reaching childbearing age. Pregnancy is a unique and complex physiological state that presents numerous challenges to women with pre-existing ACHD, whether unrepaired, repaired with residual defects, or palliated[1]. Currently, about 8 in every 10000 pregnant individuals have CHD[2]. Cardiovascular (CV) conditions, including ACHD, significantly contribute to maternal morbidity and mortality, stillbirths, premature births, and neonatal deaths, posing a growing public health concern[2,3]. Guideline-directed medical therapy (GDMT) for acquired heart diseases is not directly applicable to pregnant women who require special care to ensure optimal maternal and fetal outcomes. Several factors, including the complexity of CHD, unrepaired defects, and socioeconomic disparities, predict higher complication rates for pregnant women and their offspring. Most of the complications during pregnancy can be prevented through enhanced provider education and proper risk stratification, as recommended by leading societal guidelines, including those from the American College of Cardiology (ACC)/American Heart Association (AHA), European Society of Cardiology (ESC), Canadian Cardiovascular Society, International Society for Adult Congenital Heart Disease (ISACHD), and American College of Obstetricians and Gynecologists (ACOG)[4-9]. The evolving field of cardio-obstetrics (Figure 1) is a beacon of hope, involving a multidisciplinary team to surveil patients' CV health for preconception, antenatal, and postpartum care[10,11]. The cardio-obstetrics team includes perinatologists (maternal-fetal medicine physicians), ACHD cardiologists, heart failure (HF) cardiologists, cardiac and obstetric anesthesiologists, pharmacists, neonatologists, nurses, and social workers, and offers a comprehensive approach tailored to each patient's specific needs. This review emphasizes understanding pregnancy physiology, evaluating maternal and fetal risks during labor and delivery, management of CV complications such as stroke, HF, and arrhythmia, postpartum care, identifying areas for practice improvement, and exploring future directions (Figure 2).

Figure 1 Cardio-obstetric team. ACHD: Adult congenital heart disease; EP: Electrophysiology; HF: Heart failure; L-D: Labor and delivery.

Figure 2 Overall summary of management of adult congenital heart disease during pregnancy. CO: Cardiac output; ACHD: Adult congenital heart disease; CV: Cardiovascular; SVR: systemic vascular resistance.

NORMAL PHYSIOLOGICAL CHANGES DURING PREGNANCY

During pregnancy, the CV system undergoes significant changes (Table 1), characterized by an increase in cardiac output (CO), reaching its height between 16 and 28 weeks and rises an additional 30% during labor, due to an increased heart rate (HR) of 10-20 beats/minute and expanded blood volume[12]. Blood volume increases by 30% to 50%, and systemic vascular resistance (SVR) decreases due to higher levels of estradiol and prostacyclin, leading to lower blood pressure (BP) that peaks at 24 weeks of gestation before returning to preconception levels by term[13,14]. Pulmonary vascular resistance decreases by approximately 24% by the eighth week of gestation, accommodating a 47% increase in pulmonary flow[15,16]. Venous pressure, especially in the lower extremities, rises due to the growing uterus's pressure on pelvic veins and increased blood volume, leading to dependent edema, which can be confused with signs of HF[17]. Additionally, the dilutional effect of increased plasma volume can result in physiological anemia. These physiological changes are exacerbated in twin pregnancies[18]. The above physiologic adaptations ensure adequate fetal blood flow and are generally well-tolerated in healthy pregnant women. However, in patients with preexisting ACHD, these hemodynamic changes during pregnancy pose many challenges.

Table 1 Physiological changes during pregnancy and delivery.

Changes	Variables	First trimester	Second trimester	Third trimester	Delivery
Hemodynamic	CO	Small increase	Moderate increase	Moderate increase	Significant increase
	SVR	Mild decrease	Moderate decrease	Moderate decrease	-
	PVR	Mild decrease	Mild decrease	Mild decrease	Mild increase
	HR	Small increase	Moderate increase	Significant increase	Very significant increase
	BP	Mild decrease	Mild decrease	No change	Mild increase
WBC	WBC count	-	-	-	High
RBC	RBC mass	Small increase	Moderate increase	Moderate increase	-
Blood volume	Plasma volume	Moderate increase	Moderate increase	Very significant increase	Extremely significant increase
Remodeling in heart	LV mass	Small increase	Small increase	Small increase	-
	Chamber sizes	-	-	4-chamber enlargement	-
Aorta	Distensibility	Increase	-	-	-
Respiratory minute ventilation	O2 saturation1	Small increase	Moderate increase	Moderate increase	-
Cardiac biomarkers	BNP	No change	-	-	Mild increase
	cTn	No change	-	-	-
	CK-MB	Increase	-	-	-
	D-dimer	Small increase	Moderate increase	Significant increase	-
ECG changes	P wave	Small increase	Plateau	-	-
	Q wave	-	-	Prominent Q wave in inferior and anterolateral leads	-
	QTc	-	-	Mild increase	-
	ST changes	-	-	-	ST depression after cesarean section delivery
Arrhythmia	APC	Common	-	-	-
	PVC	Common	-	-	-

¹O₂ saturation < 95% is abnormal during pregnancy and needs investigation.

CO: Cardiac output; SVR: Systemic vascular resistance; PVR: Pulmonary vascular resistance; HR: Heart rate; BP: Blood pressure; WBC: White blood cells; RBC: Red blood cells; LV: Left ventricle; BNP: Brain natriuretic peptide; CK-MB: Creatine kinase-isoenzyme MB; ECG: Electrocardiography; cTn: Cardiac troponin; APC: Atrial premature contraction; PVC: Premature ventricular contraction.

ASSESSMENT AND RISK STRATIFICATION

Highlighting the significance of preconception counseling for women with ACHD is essential due to the potential risks involved. These include hemodynamic deterioration with unplanned pregnancy, the risk of CHD in the offspring of parents with ACHD, and the potential teratogenicity of cardiac medications. A comprehensive evaluation, encompassing medical history for prior cardiac surgeries, history of arrhythmias, interventional procedures, physical examination, electrocardiogram, echocardiogram, and other relevant diagnostic tests such as serial monitoring of brain natriuretic peptide (BNP)/N-terminal fragment of the BNP precursor (NT-proBNP), forms the basis of effective care. Risk stratification, considering CHD's anatomic complexity and physiological stage[1], New York Heart Association (NYHA) functional class, and associated comorbidities, is the key to proactive management. Cardiopulmonary exercise testing (CPET) is a valuable tool for assessing functional capacity, evaluating cardiac and pulmonary pathology, and providing guidance on prognosis and interventional recommendations before pregnancy[19]. For parents with inherited cardiac conditions, a formal genetic evaluation is recommended to discuss the transmission of the disease to offspring[20].

Risk scoring systems, such as the modified World Health Organization (WHO) classification (adopted by the 2018 ESC guidelines)[6], Harris score[21], CARPREG II risk score[22], and ZAHARA risk score[23], estimate the risk of adverse maternal and fetal outcomes in pregnant women with ACHD. The modified WHO (mWHO) classification system for maternal CV risk offers the best approach to implementing risk assessment[24] and guiding management decisions (Figure 3). Patients are classified into minimal risk (class I), low to moderate risk (class II), high risk (class III), and extremely high risk (class IV), where pregnancy is contraindicated. Women in classes I and II can be cared for in a peripheral hospital, whereas those in classes II-III and III should be managed in a tertiary center with a cardio-obstetric team. Figure 4A illustrates the risk of cardiac events per mWHO class, and Figure 4B describes the composite risk of adverse effects by the integration of mWHO, CARPREG, ZAHARA, and ROPAC risk scores.

Figure 3 Modified World Health Organization classification for maternal risk associated with adult congenital heart disease. mWHO: Modified World Health Organization; PLE: Protein-losing enteropathy; CHD: Congenital heart disease; LV: Left ventricle; LVEF: Left ventricular ejection fraction; AS: Aortic stenosis; MS: Mitral stenosis; HCM: Hypertrophic cardiomyopathy; PS: Pulmonary stenosis; VSD: Ventricular septal defect; PDA: Patent ductus arteriosus; MVP: Mitral valve prolapse; ASD: Atrial septal defect; PAC: Premature atrial contraction; PVC: Premature ventricular contraction.

Figure 4 Risk stratification for women with ACHD during pregnancy. A: The risk of cardiac events per modified World Health Organization (mWHO) class; B: Composite risk comparison for cardiac events in women with adult congenital heart disease during pregnancy: mWHO class, CARPEG II, and ZAHARA scores. mWHO: Modified World Health Organization.

COMMON ACHD LESIONS IN PREGNANCY

The modified WHO classification emphasizes primary anatomic pathology rather than functional status, offering broader predictions about expected maternal outcomes. However, there is substantial diversity in ACHD patient anatomy, types of previous intervention/reconstruction, and physiology (including residual hemodynamically significant lesions and/or cyanosis), all of which collectively affect individual management. Table 2 describes key clinical features of different ACHD types.

Table 2 Common congenital and valvular heart disease encountered in pregnancy.

ACHD type	Maternal risk	Fetal risk	Key clinical considerations
ASD	Low risk (< 5% arrhythmia, endocarditis, TE)	Low fetal mortality	DVT prophylaxis; consider anticoagulation if high-risk; aspirin in select cases
VSD	Similar to ASD	Low fetal mortality, CHD recurrence 27%	Standard management; low risk overall
Tetralogy of Fallot (repaired)	Low cardiac event rate, arrhythmia (2%-6%)	Low fetal risk	Elective PVR if RV dysfunction or dilation
CoA	HTN (5%-30%), rare dissection	Low fetal mortality, CHD recurrence 4%	Avoid pregnancy in severe CoA (mWHO IV); control BP carefully
Ebstein anomaly	HF 3%, arrhythmia 4%	Preterm 22%	Assess cyanosis, degree of TR, and RV function
d-transposition of great arteries s/p atrial switch	HF 10%, arrhythmia 15%	Preterm 34%-38%, low CHD recurrence	Assess systemic ventricular function and TR
ccTGA/l-TGA	HF 10%, cardiac event 2%	Preterm 9%, CHD recurrence 36%	Assess systemic RV, TR, and heart block risk
Cyanotic CHD (unrepaired)	High maternal risk (HF 19%, TE 3.6%)	Fetal mortality 12%, preterm 45%	Contraindicated for pregnancy; require thromboembolism prophylaxis, iron support
Eisenmenger syndrome	Very high maternal mortality (33%), TE 18%	Fetal mortality up to 30%, preterm 65%	Pregnancy is contraindicated; PDE-5i/prostanoids may be used, endothelin antagonists contraindicated
Fontan circulation	HF 3%-11%, arrhythmia up to 37%	Preterm 28%-59%, live birth only 45% of evidence of Fontan failure, postpartum hemorrhage 14%	Avoid pregnancy in complicated Fontan; anticoagulation recommended
Severe mitral stenosis	Mortality 3%, HF 37%, arrhythmia 16%	Fetal mortality 6%, preterm 18%	Severe MS = mWHO IV (contraindicated); moderate = mWHO III
Severe aortic stenosis	Mortality 2%, HF 9%, arrhythmia 4%	Fetal mortality 5%, preterm 4%	Severe symptomatic AS = mWHO IV; assisted delivery may be considered
Severe pulmonary stenosis	Generally well tolerated; worsening function possible	No significant fetal effects observed	Monitor for worsening symptoms; limited data
Moderate/severe AV valve regurgitation	Mortality < 1%, HF 8%-11%, arrhythmia 6%-8%	Fetal mortality 0%-1%, preterm 12%-15%	Worse prognosis with pulmonary hypertension or LV dysfunction
Moderate/severe semilunar valve regurgitation	Mortality < 1%, HF 1%-3%, arrhythmia 0%-3%	Fetal mortality 1%-8%, preterm 5%-10%	Same considerations as AV regurgitation

TE: Thromboembolism; DVT: Deep vein thrombosis; PVR: Pulmonary valve replacement, RV: Right ventricle; CoA: Coarctation of the aorta; mWHO: Modified world health organization classification; HTN: Hypertension; HF: Heart failure; TR: Tricuspid regurgitation; PDE-5i: Phosphodiesterase 5 inhibitor; AV: Atrioventricular valve regurgitation; s/p: Status post; CHD: Congenital heart disease; BP: Blood pressure; ACHD: Adult congenital heart disease; ASD: Atrial septal defect; ccTGA: Congenitally corrected transposition of the great arteries; l-TGA: L-transposition of great arteries; VSD: ventricular septal defect; MS: Mitral stenosis; AS: Aortic stenosis; LV: Left ventricle.

Left heart stenotic ACHD

Left heart stenotic ACHD includes aortic stenosis (AS), mitral stenosis (MS), and the coarctation of the aorta (CoA; Figure 5A).

Figure 5 Adult congenital heart disease in women during pregnancy. A: Aortic stenosis, mitral stenosis, coarctation of the aorta; B: Unrepaired tetralogy of Fallot; C: Uncomplicated Ebstein anomaly; D: Extra-cardiac Fontan; E: Congenitally corrected transpositions of great arteries; F: Transposition of great arteries after Senning/mustard; G: Transposition of great arteries after arterial switch operation; H: Left to right shunt lesions (atrial septal defect, ventricular septal defect, and patent ductus arteriosus). ASD: Atrial septal defect; VSD: Ventricular septal defect; PDA: Patent ductus arteriosus; AO: Aorta; PA: Pulmonary artery; RV: Right ventricle; RA: Right atrium; LV: Left ventricle; LA: Left atrium; SVC: Superior venacava; IVC: Inferior venacava; TGA: Transposition of the great arteries arteries.

AS: Pregnancy is contraindicated in symptomatic AS or severe asymptomatic AS with severely impaired left ventricular (LV) function [LV ejection fraction (LVEF) < 30%, mWHO-IV] due to high maternal morbidity and mortality risks[6,25,26]. It is important to highlight that, according to the CARPREG II[21] and ZAHARA[22] scores, a peak gradient ≥ 50 mmHg across the aortic valve, a subaortic gradient ≥ 30 mmHg, or an aortic valve area ≤ 1.5 cm² is deemed high risk during pregnancy[27]. Mild to moderate AS lesions are usually well-tolerated unless associated with LV dysfunction or aortic regurgitation (AR). Continuous invasive hemodynamic monitoring is required for severe AS. Diuretics should be used cautiously. Balloon dilatation or transcatheter aortic valve replacement (TAVR) may be considered in advanced pregnancy stages[27]. Surgery, if needed, is recommended to be done between the 13^th and 28^th weeks of gestation or should be considered after early cesarean delivery. Patients with LV outflow tract obstruction and CoA are at higher risk of small-for-gestational-age (SGA) infants and premature births[28]. Regional anesthesia is suitable, but single-shot spinal anesthesia should be avoided due to sudden hemodynamic changes. Postpartum care includes monitoring for HF and deterioration of LV function.

MS: MS poses a significant risk during pregnancy, with pulmonary edema being the most common complication[29]. Pre-pregnancy severe MS (< 1.5 cm² valve area) should be corrected before pregnancy. Anticoagulation is indicated for atrial fibrillation, left atrial (LA) thrombosis, prior embolism, spontaneous echo contrast in the LA, LA volume index ≥ 60 mL/m², or when associated with HF. Mild MS is usually well-tolerated, while moderate or severe MS often leads to HF symptoms, especially in the second trimester. HR control is crucial, with beta blocker (BB; metoprolol) and calcium channel blocker (CCB; diltiazem), which are safe during pregnancy[30]. Diuretics should be used cautiously. Physical activity should be limited; bed rest is advised in moderate to severe cases. MS can cause atrial fibrillation, which is challenging to manage during pregnancy, and electrical cardioversion may be needed[31]. Balloon valvuloplasty is considered if medical management fails, preferably in the second trimester[27]. In most cases, congenital MS due to parachute mitral valve is not amenable to balloon valvuloplasty, highlighting the importance of accurate pre-conception valve characterization. Planned cesarean section is preferred for symptomatic severe MS, while mild MS can be managed with vaginal delivery and epidural analgesia. Maternal mortality is highest during labor and the immediate postpartum period. Postpartum care includes monitoring for pulmonary edema and fetal outcomes like intrauterine growth retardation (IUGR) and preterm delivery.

CoA: Women with unrepaired CoA, classified as mWHO class IV, are at risk for aortic dissection at the site of narrowing, placental hypoperfusion, and IUGR; therefore, pregnancy is contraindicated[6]. Before conception, it is recommended that patients undergo special imaging studies, such as computed tomography or cardiac magnetic resonance imaging (CMR), to assess aortic structure and dimensions. Consequently, unrepaired CoA or aortic aneurysm (aortic diameter > 5 cm) should be repaired before proceeding with pregnancy. According to the mWHO stratification, those with repaired CoA but having residual coarctation (> 20 mmHg gradient or aortic lumen < 1.2 cm) and aneurysm at the prior coarctation site fall into mWHO classes II and III. The primary concern for women with a history of prior CoA, even after repair, is the development of hypertension (30%) and preeclampsia during pregnancy[32,33]. Aspirin 81 mg daily beginning in the second trimester given increased risk of pre-eclampsia is recommended. During pregnancy, close BP monitoring should be conducted at least every trimester with careful measurement of all four extremities. Labetalol, nifedipine, and methyldopa are the preferred medications for managing hypertension[30]. During the second trimester, it may be necessary to reduce the dosage as a 5-10 mmHg decrease in systolic BP commonly occurs due to pregnancy-related physiological changes. Diuretics should be used cautiously as they can lead to placental hypoperfusion. Salt restrictions for pregnancy-related hypertension are not recommended because of concerns for poor fetal growth[34]. Hypertensive crises may require intravenous sodium nitroprusside or nitroglycerin. For cases of refractory BP control or maternal or fetal hemodynamic compromise, invasive interventions such as percutaneous stenting of re-coarctation sites may be considered[35].

Mechanical valve for valvular ACHD: Patients with a history of valve replacement who are hospitalized for delivery face a significant risk of adverse maternal and fetal events, irrespective of the valve type. Studies indicate that outcomes for mechanical heart valves and bioprosthetic heart valves are comparable[36]. Managing anticoagulation in women with mechanical valves is challenging due to the risk of valve thrombosis, and warfarin can cause teratogenic effects, particularly during weeks 6-12 of pregnancy. The risk to the fetus depends on the dose of warfarin, with lower risks observed when the daily dose is ≤ 5 mg before conception. Warfarin is preferred if the dose requirement is < 5 mg/day during the second and third trimesters[36]. Heparin and low molecular weight heparin (LMWH) can be used during the first trimester. Careful management of LMWH is crucial, with a peak anti-Xa target of 1.0-1.4 IU/mL taken 3-4 hours after a twice-daily LMWH dose[37]. Changes in anticoagulation regimen during pregnancy should be handled while hospitalized, providing a sense of security and reassurance. Women on warfarin should transition to LMWH or heparin at 36 weeks' gestation to minimize the risk of fetal hemorrhage and maternal bleeding during delivery. Regional anesthesia is contraindicated within 24 hours of the last LMWH dose. If labor begins while the mother is on warfarin, a cesarean delivery is advised. Administering vitamin K to the mother does not guarantee reversal of warfarin effects in the fetus.

Pulmonary stenosis

In pulmonary stenosis (PS), the increased CO during pregnancy leads to a rise in the transvalvular gradient but is typically well tolerated during pregnancy[38]. Medical optimization with diuretics to control right-sided HF is sometimes necessary. Balloon valvuloplasty may be considered in patients who remain symptomatic despite medical management. Vaginal delivery is recommended in medically optimized patients. However, it's crucial to stress the importance of BP control, as women with isolated PS may be at increased risk for hypertensive disorder of pregnancy, underscoring the significance of this aspect[39].

Tetralogy of Fallot

For patients with unrepaired tetralogy of Fallot (TOF; Figure 5B), surgical repair is recommended before pregnancy. Pregnancy is not advised for women with unrepaired TOF whose oxygen (O₂) saturation is below 90%, due to the significant maternal and perinatal complications associated with cyanosis. However, women with repaired TOF generally tolerate pregnancy well (mWHO risk class II)[6]. However, up to 12% of these patients who had an initial repair with a transannular patch are particularly prone to severe pulmonary regurgitation (PR) and subsequent right ventricle (RV) dilation. RV dysfunction and/or moderate to severe PR are significant risk factors for right-sided HF, arrhythmia, and thromboembolism (TE)[40]. Treatment includes diuretics and afterload-reducing medications such as hydralazine. Pulmonary valve replacement may be required, although the best timing of this intervention is still a matter of debate[1]. Although uncommon, adverse maternal events can occur, often linked to LV dysfunction, severe pulmonary hypertension (PH), and significant PR with RV dysfunction[41]. Depending on the severity of symptoms and myocardial dysfunction, early delivery may be required, with potential escalation to admissions into the intensive care unit (ICU) and mechanical support. However, vaginal delivery is preferred in most women with repaired TOF except those with decompensated HF.

Valvular regurgitant ACHD

For pregnant women with mild to moderate mitral regurgitation (MR) and AR, it's important to focus on managing symptoms. Chronic mild to moderate AR and MR are typically well tolerated, but women with severe MR are at increased risk of HF, especially in the postpartum period, due to volume shifts[42]. Therefore, treatment should focus on using diuretics to maintain euvolemia, BB for HR control, and vasodilators like hydralazine and nitrates for afterload reduction[30]. Atenolol is not recommended due to the increased risk of fetal growth restriction. Renin-angiotensin-aldosterone system inhibitors are contraindicated in pregnancy due to their teratogenic effects. Labetalol, methyldopa, nifedipine, or amlodipine can be used safely for afterload reduction[30]. Patients with AR and/or MR with pre-existing symptoms or LV systolic dysfunction can progress to HF.

Pulmonic and tricuspid regurgitation (TR) are commonly associated with ACHD. TR is more frequent due to infective endocarditis or Ebstein anomaly. When there is no pre-existing right-sided HF before conception, women generally fare well during pregnancy. However, those who have undergone right-sided heart valve procedures are susceptible to atrial arrhythmias and right-sided HF, potentially necessitating diuretic therapy in the later stages of pregnancy and postpartum. Surgical intervention for regurgitant lesions is rarely required during pregnancy, except in cases of infective endocarditis complicated by valvular regurgitation due to the potentially life-threatening risks to the mother and fetus if it goes untreated. Maternal risk is largely determined by the presence of concomitant LV dysfunction or PH. Additionally, severe symptomatic TR or RV dysfunction can increase maternal risk, particularly through the development of atrial fibrillation. Vaginal delivery with epidural anesthesia and a shortened second stage of labor is advisable to minimize hemodynamic stress.

Ebstein anomaly

In women with uncomplicated Ebstein’s anomaly (Figure 5C), pregnancy is often well-tolerated (mWHO risk class II)[6]. Ebstein anomaly is often associated with atrial septal defect (ASD), right atrial (RA) dilation, and Wolff-Parkinson-White syndrome. Consequently, pregnancy may lead to progressive cyanosis, TE and/or arrhythmias in women at risk. The prognosis is less favorable if RV dysfunction is already present before pregnancy. The fatal complication rate (3%-17%) correlates closely with the degree of HF and with associated left-sided valve disease or cyanosis[43-45]. It's crucial to advise against pregnancy for symptomatic patients with cyanosis and/or HF (mWHO risk class IV)[6]. Women with cyanosis (an arterial O₂ saturation < 90%) and hematocrit > 60% are indicators of a poor prognosis. Women with cyanotic ACHD face an elevated risk of miscarriage, preterm birth, fetal distress, and congenital anomalies in their children.

Fontan circulation

Fontan circulation represents a complex form of ACHD in which systemic venous blood flows passively into the pulmonary arteries without a subpulmonary ventricle[46]. Over the past two decades, most centers have transitioned to performing lateral tunnel or extracardiac conduit Fontan procedures (Figure 5D), given the long-term complications of the atrio-pulmonary Fontan approach, such as significant RA dilation, atrial arrhythmias, and increased risk for TE[47-49]. Pregnancy in women with Fontan circulation poses substantial challenges due to increased volume and pressure demands on the circuit[50]. This often leads to complications such as hepatic congestion, gastric congestion, and cardiorenal syndrome arising from renal venous congestion[51].

A comprehensive pre-pregnancy evaluation of Fontan physiology is critical and should include echocardiography, CMR, cardiac catheterization, and liver biochemical and ultrasound assessments[52]. Pregnancy is contraindicated (mWHO class IV) in the presence of severe complications like cyanosis, impaired ventricular function, atrioventricular valve (AV) regurgitation, arrhythmia, elevated Fontan pressures, protein-losing enteropathy, or plastic bronchitis[6]. Also, women with Fontan circulation face heightened risks of HF, TE, and hemorrhage during pregnancy and the postpartum period[53,54]. Expert consensus recommends therapeutic LMWH and aspirin for those with high thromboembolic risk and low-dose aspirin or prophylactic LMWH for those at lower risk[55]. Despite the complexity of management, maternal mortality during pregnancy is relatively low, and patients can often be managed effectively without significant long-term sequelae[56].

Fetal outcomes, however, tend to be less favorable. The live birth rate among women with Fontan circulation is reported at approximately 40%-50%[56]. Common complications include prematurity, IUGR, and SGA, driven by adverse hemodynamics, maternal medication effects, and the neurohormonal environment of Fontan circulation[57,58]. Additionally, BB (atenolol) is associated with risks such as IUGR, preterm birth, neonatal bradycardia, and hypoglycemia[30]. Placental abnormalities, including low weight, chorionic hematoma, and histological hypoxic changes, further contribute to poor fetal outcomes[59].

The postpartum period introduces additional hemodynamic challenges as uterine blood is auto-transfused back into circulation, and pressure on the inferior vena cava from the baby’s mass is relieved. This 48-72-hour window is a critical time for monitoring, particularly in patients at risk of decompensation. Post-delivery, Fontan patients should remain in the ICU for at least 24-48 hours with close monitoring of fluid balance, HR, and BP. A thorough echocardiographic assessment before discharge is essential, focusing on Fontan conduit flow, thrombus detection, AV regurgitation, and ventricular function. TE prophylaxis should continue for at least six weeks postpartum[60]. Prolonged LMWH use is preferred to minimize the risk of severe bleeding, which can be unpredictable and difficult to manage with warfarin therapy.

Congenital systemic RV with bi-ventricular circulation

Patients with systemic morphological RV (sRV), including congenitally corrected transposition of the great arteries (ccTGA) or also called L-transposition of great arteries (Figure 5E) and dextro-transposition of the great arteries (d-TGA) with a Mustard or Senning atrial baffle repair (Figure 5F), have a high likelihood of maternal and neonatal morbidity and IUGR[61]. Pregnancy is generally well tolerated, but an sRV ejection fraction < 40% and clinical signs of HF and severe TR before pregnancy are significant risk factors for maternal complications[62]. These include maternal death, supraventricular or ventricular arrhythmias requiring treatment, HF, aortic dissection, endocarditis, ischemic coronary events, and other TE events[63].

Contrary to d-TGA after Senning and Mustard (which is no longer the preferred surgical procedure), women with a history of d-TGA and an arterial switch operation (Figure 5G), with normal LV function pre-pregnancy and normal CPET, pregnancy is tolerated relatively well (mWHO II)[64]. During preconception counseling, most women with a normal CPET should be reassured that the risk of pregnancy is low[65].

Left-to-right shunt ACHD

Left-to-right shunt lesions, such as ASD, ventricular septal defect (VSD), partial anomalous pulmonary venous return, and patent ductus arteriosus (PDA), result in increased pulmonary blood flow (Figure 5H) and are at risk of developing PH. ASD is the most common form of CHD observed during pregnancy. In contrast, undiagnosed moderate or large VSD and PDA are extremely rare. Most women with a small VSD or PDA, uncomplicated by PH, have a low risk (mWHO I) of hemodynamic deterioration during pregnancy, as these shunt lesions are highly resistant to flow[66]. Atrial arrhythmias are common in patients with a prior history of delayed ASD closure. In the rare case of marked clinical deterioration, catheter-based closure of the ASD is the first-line treatment. However, repaired atrioventricular septal defect (AVSD) with significant left AV valve regurgitation poses a higher risk of pregnancy complications (class III) and should be managed as described under MR[30,42]. Vaginal delivery is generally preferred, but cesarean delivery may be indicated in cases of severe ventricular dysfunction or hemodynamic instability. Close monitoring during the postpartum period is essential due to the significant hemodynamic changes after delivery.

Eisenmenger syndrome

Eisenmenger syndrome (ES) is a severe form of PH that arises in patients with AVSD, VSD, ASD, or PDA, leading to increased pulmonary blood flow and irreversible pulmonary vascular disease. Preconception counseling is essential for women with ES, emphasizing that pregnancy is contraindicated (mWHO class IV)[6]. This counseling involves a detailed discussion of the significant maternal and fetal risks associated with ES, including elevated maternal mortality, arrhythmias, HF, and fetal complications such as prematurity, IUGR, and stillbirth[67].

With advancements in PH treatment and new approaches to managing pregnant women during the peripartum period, maternal mortality has decreased but remains significant, ranging from 11% to 25%[68]. There have been reports of favorable pregnancy outcomes in women with ES[69]. Despite this, pregnancy remains associated with unpredictable risks and may accelerate the progression of PH. Women with PH can deteriorate at any time during or after pregnancy, necessitating that physicians inform patients about the risks so that women and their families can make informed decisions[70]. If pregnancy is continued, PH therapies need to be adjusted. It is recommended to discontinue endothelin receptor antagonists (ERA) such as bosentan, ambrisentan, macitentan, soluble guanylate cyclase stimulators such as riociguat, and oral prostaglandin receptor agonists such as selexipag due to potential or unknown teratogenicity[30,71]. Despite limited evidence, CCB (nifedipine), phosphodiesterase type 5 inhibitors (sildenafil, tadalafil), and parenteral and inhaled prostanoids are considered safe during pregnancy[30,72,73].

Delivery planning should be individualized based on the severity of PH, maternal and fetal status, and obstetric considerations. This individualized approach, which considers the unique circumstances of each patient, is a considerate and attentive way to manage the situation. Vaginal delivery is generally well-tolerated in women with well-compensated ES, but the mode of delivery should be determined in consultation with a multidisciplinary cardio-obstetrics team[74]. In some cases, cesarean section may be preferred to minimize the risk of hemodynamic changes during labor and delivery. Close monitoring should continue in the postpartum period to detect and manage any potential complications, such as HF exacerbation or arrhythmias[75]. Medications should be adjusted as the pharmacokinetics can change throughout gestation, and contraception should be discussed to prevent unplanned pregnancies in women with ongoing risks[76].

Aortopathies

Marfan syndrome: Marfan syndrome is diagnosed based on revised Ghent criteria and is confirmed by genetic testing[77]. The risk of aortic dissection during pregnancy in women with Marfan syndrome is approximately 3%[78]. Aortic size significantly influences this risk, with even those with an aortic root diameter of < 4 cm facing a 1% dissection risk. Although data is limited, it is generally advised that women with an aortic root diameter > 4.5 cm avoid pregnancy due to the heightened risk of dissection[79]. For those with an aortic root size between 4 and 4.5 cm, additional factors such as the family history of dissection and the rate of aortic growth (≥ 0.3 cm/year) are considered high-risk. Distal aortic dissection and dissection of other vessels also pose risks. Consequently, even after successful aortic root replacement, patients remain susceptible to further events in the abdominal aorta[80]. Studies on aortic growth during pregnancy in Marfan patients have shown mixed results; some indicate no significant increase, while others report growth exceeding 0.3 cm, with a partial decrease in diameter postpartum[81]. Other significant cardiac complications include progressive MR due to mitral valve prolapse, new arrhythmias, and HF resulting from ventricular dysfunction[82].

Bicuspid aortic valve: The bicuspid aortic valve is more common (2% of the population), but aortopathy associated with bicuspid aortic valve accounts for 6% of type A dissections during pregnancy[83]. The current evidence supports that hemodynamic wall stress, in combination with an underlying connective tissue disorder or genetic abnormality of the ascending aortic media, leads to bicuspid aortopathy, but overall, the risk of aortic dissection is small. There is a need for close monitoring of aortic dimensions with echocardiography or other imaging modalities to assess for aortic dilation in women planning for pregnancy[84]. Optimization of BP control during pregnancy, labor and delivery is warranted with medications, such as BB, to reduce the risk of aortic complications. Pregnancy should be avoided when the aorta diameter is > 5 cm with a pre-existing bicuspid aortic valve[6]. Careful management of chronic or gestational hypertension should include labetalol, nifedipine, and methyldopa during pregnancy.

Loeys-Dietz syndrome: Loeys-Dietz syndrome (LDS) is an autosomal dominant connective tissue disorder caused by mutations in TGFβR1, TGFβR2, TGFβ2, TGFβ3, and SMAD3 genes[85]. It affects connective tissue and can lead to aortic dissection, with most dissections occurring in the third trimester (50%) or postpartum (33%)[86]. Vessel tortuosity in the head and neck is a hallmark finding for this disorder and may extend to the uterine vessels. Identification of women with LDS before or early in pregnancy is essential to allow for adequate surveillance of aortopathy and to ensure delivery at a tertiary care center with expertise in aortic surgery. Managing LDS during pregnancy requires a multidisciplinary approach to ensure both maternal and fetal safety. Optimization of BP control with medications, such as labetalol, nifedipine, and methyldopa, is needed to reduce the risk of aortic complications. Recent studies in LDS have not shown that vaginal delivery increases the risk of uterine rupture. Thus, vaginal delivery may be considered[87]. The ACC and ESC recommend CMR imaging for the aorta post-delivery and at six months postpartum to monitor aortopathy[6,88].

Turner syndrome: Turner syndrome (TS) is linked to a higher risk of CHD, aortic dilation, hypertension, diabetes, and atherosclerotic events[89]. Although aortic dissection is rare in TS, it occurs six times more frequently in younger individuals compared to the general population[90]. Pregnancies in women with TS, conceived with either autologous or donated oocytes, are considered high risk because of the risks of aortic dissection, especially when associated with bicuspid aortic valve and CoA. Pregnancy should be avoided if the aortic diameter index exceeds 2.5 cm/m². Even after aortic root surgery, patients remain at risk for type B dissection[91]. Effective BP control and diabetes management are crucial for all TS patients during pregnancy.

Vascular Ehlers-Danlos syndrome: Severe vascular complications are predominantly associated with type IV Ehlers-Danlos syndrome (EDS). Maternal mortality is notably high due to risks of uterine rupture and dissection of major arteries and veins. Consequently, pregnancy is considered extremely high risk and is generally not recommended. Women with EDS should participate in a shared decision-making process when considering pregnancy[92].

ROLE OF INVASIVE PROCEDURES

TAVR

Ideally, severe AS is identified and treated before conception. Preconception treatment options for native and bioprosthetic aortic valves include surgical aortic valve replacement (SAVR), TAVR, or a Ross procedure. During pregnancy, percutaneous balloon valvuloplasty can alleviate symptoms in native AS and may temporarily improve hemodynamics in patients with severe symptoms who do not respond to medical management. Balloon angioplasty typically serves as a palliative measure, postponing surgery until after childbirth. However, it carries the risk of significant AR and related hemodynamic instability. TAVR offers an alternative method for aortic valve replacement with lower immediate risks to both the mother and the fetus compared to SAVR.

The role of TAVR in pregnant women with AS is generally limited due to the potential for greater fetal exposure to radiation and the more critical nature of aortic valve function for the mother's overall health during pregnancy. Orwat et al[26] found that the peak aortic gradient of ≥ 50 mmHg before pregnancy was an independent predictor of complications during pregnancy. The development of symptoms such as dyspnea, near syncope or syncope, and arrhythmias is also an indicator of a complicated course[93]. The decision to proceed with TAVR during pregnancy should be made on a case-by-case basis, considering the potential risks and benefits to both the mother and the fetus in consultation with a cardio-obstetrics team. Fetal radiation exposure can cause miscarriage, IUGR, mental retardation, and major malformations. The risk to the fetus depends on the radiation dose and gestational age. The highest risk is during organogenesis (weeks 2-8) and neuronal stem cell proliferation (weeks 8-14)[94]. There are anecdotal experiences of successful TAVR during pregnancy, but further research is needed to recommend TAVR as an option for the treatment of severe symptomatic AS during pregnancy[95-101]. There is limited data available in the literature on how women with a previous TAVR for severe AS or TAVR in prior SAVR will tolerate subsequent pregnancies[102].

Transcatheter pulmonary valve replacement

Like TAVR, transcatheter pulmonary valve replacement (TPVR) during pregnancy is classified as a high-risk procedure. However, it can be performed in specific scenarios where the mother's cardiac health is severely compromised by a failing RV, particularly when there is a history of prior surgical repair or intervention for RV outflow tract, such as TOF with residual PS and PR. Recently, there have been a few reported cases of successful TPVR during pregnancy[103,104]. For pregnant women with significant PS and PR who exhibit symptoms or are at risk of maternal or fetal complications, TPVR may be considered a viable alternative to surgical intervention[93]. Duarte et al[105] reported no major adverse cardiac events, including endocarditis or mortality, in nine pregnancies among seven women with various forms of ACHD who had undergone TPVR before pregnancy. From an obstetric perspective, it is important to note that preterm birth was common in these pregnancies, occurring in five out of nine cases[105].

MANAGEMENT OF CV COMPLICATIONS

Maternal history of ACHD increases the risk of stroke, HF, and arrhythmia during pregnancy and the peripartum period[2].

Stroke

Pregnant and postpartum women have a threefold increased risk of stroke compared to non-pregnant women of the same age, and this risk is further heightened by the presence of ACHD[106]. Physiological changes during pregnancy, including hemodynamic shifts, venous stasis, hypercoagulability, and immune modulation, contribute to this heightened risk. The immediate postpartum period presents the highest stroke risk for mothers[60,107]. Common causes of pregnancy-related strokes include TE associated with cyanotic ACHD and Fontan circulation, cervical artery dissection, cerebral venous thrombosis, cerebral vasospasm or subarachnoid hemorrhage from reversible cerebral vasoconstriction syndrome, and hypertensive intracerebral hemorrhage, often linked with posterior reversible encephalopathy syndrome[108]. Risk factors for stroke encompass migraines, hypertensive disorders of pregnancy, diabetes, infections, cerebrovascular malformations, moyamoya disease, antiphospholipid syndrome, and fibromuscular dysplasia[107,108]. Urgent neurological assessment is warranted for pregnant or postpartum women presenting with symptoms such as new-onset headache, high BP, severe pain, or focal neurological deficits. Managing high-risk cerebrovascular conditions in pregnant women demands personalized care and close monitoring by a multidisciplinary cardio-obstetrics team and neurologist. Delivery planning should focus on obstetric considerations, though cesarean delivery might be necessary for patients with recent acute stroke and elevated intracranial pressure[109]. Experiencing a stroke during pregnancy can lead to lasting health issues, making it crucial to transition postpartum care to either primary or specialty care to ensure optimal vascular health[110].

HF

HF is the most common complication among women with preexisting heart disease, regardless of the cause, whether related to valvular disorders, ventricular dysfunction, PH, or ACHD[5]. The ROPAC study identified several predictors for HF during pregnancy, including cardiomyopathy, left heart stenotic ACHD, d-TGA with Mustard or Senning operation, ccTGA, ES, Fontan, pre-existing HF, and PH[59,111]. Those with repaired TOF or pulmonary atresia with residual PS and PR, are more likely to develop right-sided HF[5,6]. Pregnancy is contraindicated in women with severe systemic ventricular dysfunction (LVEF < 30%), NYHA class III or IV)[6,112].

For pregnant women with stable HF on medications, monitoring during pregnancy includes echocardiograms every trimester and monthly after 24 weeks until delivery[113]. Drug levels should be monitored throughout pregnancy and postpartum due to changes in plasma volume. Medications such as angiotensin receptor-neprilysin inhibitors (ARNI), sodium-glucose cotransporter-2 inhibitors (SGLT2is), angiotensin converting enzyme inhibitors (ACEis), angiotensin receptor blockers (ARBs), carvedilol, statins, spironolactone, amiodarone, and atenolol should be discontinued during pregnancy due to potential or unknown fetotoxicity, and should be substituted with alternative afterload-reducing agents such as hydralazine and oral isosorbide dinitrate[30]. Selective BBs such as metoprolol and bisoprolol are favored[30]. Women with ventricular dysfunction require close monitoring throughout pregnancy and delivery at a specialized tertiary center with a cardio-obstetrics team. Patients should be instructed to rest in a lateral decubitus position. Symptomatic women may need bed rest and may require admission to the ICU.

Acute HF usually occurs in the late second or third trimester or early postpartum, often triggered by eclampsia or preeclampsia[113]. Differentiating between normal pregnancy symptoms and HF is vital. While avoiding radiation is preferable, a chest radiograph may be necessary to diagnose pulmonary edema. Regular transthoracic echocardiograms and serum NT-pro BNP help assess heart function. Treating potential triggers like hypertension or anemia is important. Loop diuretics like furosemide should be used carefully to avoid reducing placental flow[30]. Inotropic drugs like dopamine, dobutamine, or milrinone may be used if oral HF therapies are ineffective[114]. There is some concern for excessive vasodilation with milrinone in pregnancy in the setting of already decreased SVR. If HF is refractory, care should be provided at a center equipped for a ventricular assist device (VAD)[115-119]. Pregnancy is contraindicated for women with a left VAD (LVAD), but unplanned pregnancies can still occur. In a review of nine pregnancies while on LVAD, one maternal death was reported[120]. During pregnancy, LVAD speed may need to be increased to provide adequate CO. Specific guidelines for anticoagulation for LVAD during pregnancy are not well-defined.

In select cases, pregnancy after heart transplantation can be considered[121]. Contraindications include being less than one year post-heart transplant, reduced graft function, nonadherence, presence of donor-specific antibodies, significant cardiac allograft vasculopathy, poorly controlled hypertension, diabetes, renal dysfunction, and active infections[122]. Mycophenolate mofetil and mycophenolic acid are teratogenic and should be discontinued, with azathioprine being a suitable alternative[123].

Labor induction should be based on clinical conditions, ideally after 37 weeks unless early delivery is necessary. In cases of refractory HF, early cesarean section delivery may be required. Fetal lung maturity should be addressed with corticosteroids if needed. O₂ saturation and BP should be monitored during labor, and Swan-Ganz catheterization may be used for acute HF or significant systemic ventricular dysfunction. Women should labor in the left lateral decubitus position to avoid fetal compression of the inferior vena cava, and intravenous fluids should be minimized to prevent volume overload. Post-delivery, volume status should be reassessed, and frequent clinical evaluations should continue in the postpartum period. The first 12 weeks postpartum are crucial for monitoring cardiac function, optimizing HF medications, anticoagulation, contraception, and transitioning care teams[113]. Since ARNI and SGLT2i, both carrying a class 1A recommendation in HF and offering mortality benefits[124], are unsafe for lactating women, it is important to discuss the potential cessation of breastfeeding to facilitate the rapid up-titration of GDMT for HF during the postpartum period.

Arrhythmia

According to the 2023 HRS expert consensus statement, pregnant patients with cardiac arrhythmias should be managed by a cardiac electrophysiologist[125]. Unstable arrhythmias in pregnancy should be managed with electrical cardioversion, avoiding antiarrhythmic medications in the first trimester if possible and using the lowest effective dose[31]. Amiodarone is contraindicated due to the risk of fetal thyroid and neurodevelopmental complications[30]. Supraventricular tachycardia can initially be treated with vagal maneuvers, followed by adenosine, metoprolol, and verapamil as third-line therapy[126]. Atrial fibrillation and atrial flutter can be managed with metoprolol, verapamil, and digoxin, while sotalol, flecainide, and propafenone are options if rhythm control is necessary[126]. Intravenous procainamide is used for atrial fibrillation with pre-excitation[126]. Flecainide is used during pregnancy but may cause maternal visual disturbances, prolonged QT intervals, neonatal HF at toxic levels, cholestasis, and decreased fetal HR variability[30]. Sotalol, used primarily for fetal arrhythmias, carries an increased risk of torsades de pointes due to QT prolongation[126]. ESC guidelines recommend procainamide, flecainide, or sotalol for ventricular tachycardia (VT), with electrical cardioversion for unstable VT during pregnancy[127]. Catheter ablation procedures during pregnancy should use techniques to minimize radiation exposure to as low as reasonably achievable[125]. General anesthesia is preferred over regional anesthesia for cardiac interventions performed during pregnancy. Invasive electrophysiology interventions should be carefully planned and executed with consideration for both maternal and fetal well-being.

FETAL DIAGNOSIS OF CHD IN WOMEN WITH ACHD DURING PREGNANCY

The complexity of the ACHD and whether it has been surgically repaired play crucial roles in determining the risk level of CHD in offspring[128]. Additionally, independent factors related to the cardiac and non-cardiac status of the patients, such as chromosomal anomalies in parents, cardiac treatments received during pregnancy, hypertensive disorders of pregnancy, smoking during pregnancy, gestational diabetes, and pre-pregnancy body mass index < 18.5 kg/m², also influence the outcomes[129]. First-trimester nuchal translucency screening is a significant step during routine obstetric ultrasound and can lead to a fetal echocardiogram to diagnose any CHD[130]. Babies whose parents have a chromosomal anomaly and mothers with CHD during pregnancy should have genetic counseling[131-133]. Cytogenetic fetal karyotyping was traditionally the gold standard of prenatal genetic testing, capable of detecting aneuploidy and large chromosomal rearrangements[134]. However, whole-exome sequencing (WES) has emerged as a powerful tool that sequences the entire coding region of the genome, known as the exome[135]. WES is particularly useful for identifying single-nucleotide variants, insertions, deletions, and copy number variants that may be responsible for fetal anomalies, including CHD[136]. The use of WES in prenatal diagnosis can significantly influence clinical decisions and treatment plans[137]. Prenatal diagnosis of CHD and associated chromosomal anomalies plays a crucial role in risk stratification and delivery planning. Fetal echocardiography helps predict the risk of hemodynamic compromise and identifies newborns who may require urgent cardiac interventions. This allows for the development of individualized perinatal management plans, ensuring that appropriate care is provided immediately after birth.

POSTPARTUM CARE

Figure 6 presents a holistic framework for postpartum care in women with ACHD. It highlights three domains of focus: (1) Postpartum monitoring, emphasizing the re-evaluation of cardiac function, arrhythmia surveillance, and medication optimization; (2) Obstetric risks, including considerations like maternal age, uterine rupture, prematurity, and fetal growth restrictions; and (3) Future CV risks, addressing potential complications such as hypertensive disorders, metabolic syndrome, and HF. The foremost concern is the urgent need for counseling on contraception and future pregnancy planning. This approach underlines the importance of a multidisciplinary effort to balance cardiac health, obstetric safety, and long-term CV outcomes.

Figure 6 Postpartum care for women with adult congenital heart disease. CVD: Cardiovascular disease; IUGR: Intra-uterine growth retardation.

Close cardiac monitoring should be continued in the postpartum period, with specific frequency (e.g., weekly for the first month, then bi-weekly for the next two months), to assess the mother's cardiac function, especially if she has a history of complex ACHD or has experienced any complications during pregnancy or delivery[138]. AHA statement recommends patient-centered holistic care and extending health coverage for one year postpartum to enhance maternal health outcomes and reduce disparities[139]. Women with ACHD should have a long-term care plan that includes regular cardiac evaluations and lifestyle modifications to reduce CV risks.

Medication management should be continued according to the mother's cardiac condition and the recommendations of her ACHD providers. This may involve adjusting or continuing medications for managing HF, arrhythmias, TE prophylaxis, and any potential drug interactions with breastfeeding[30,38,71]. Many medications, especially for HF, such as ACEi, ARB, ARNI, atenolol, statins, amiodarone, spironolactone, and NSAIDs, are contraindicated as these drugs are secreted in breast milk and can cause adverse effects in neonates[30]. A comprehensive resource for information on the safety of medications during lactation is available from the National Library of Medicine[140]. Discuss contraception options early in the postpartum period to prevent unintended pregnancies, which can pose significant risks for women with ACHD[141,142].

Emotional support: Women with ACHD often experience an increased prevalence of mental health issues such as depression, anxiety, or posttraumatic stress disorder related to complicated pregnancy or birth experiences[143]. Routine mental health screening, counseling, and support are essential components of care for women with ACHD[144]. If these mental health challenges go undetected and untreated, they can have significant consequences on the mother's well-being, her ability to parent, and consequently, on the cognitive and emotional development of her infant.

MANAGEMENT OF CONTRACEPTION FOR WOMEN WITH ACHD

Managing contraception for women with ACHD requires careful consideration of the individual patient's cardiac anatomic and physiologic status, reproductive goals, and potential risks associated with different contraceptive methods[141,142]. A thorough assessment of the patient's cardiac function, exercise tolerance, and risk factors for TE should be performed to guide the selection of an appropriate contraceptive method[145]. Women with ACHD should receive comprehensive counseling and education about the different contraceptive options available, their benefits, risks, potential interactions with cardiac medications, and the risk of unplanned pregnancy[145-147]. Combined hormonal contraceptives are generally considered high-risk for TE. However, they are still at a lower risk compared to pregnancy, so it's important to weigh the risk/benefit ratio and establish another highly effective method of contraception before discontinuing[145-147]. Non-hormonal contraceptive methods, such as barrier methods (e.g., condoms, diaphragms), copper intrauterine devices, or permanent methods (e.g., tubal ligation), may also be considered in women with ACHD, particularly if hormonal methods are contraindicated or not preferred[145-147]. Highly effective contraception is recommended to prevent pregnancy in women with PH. Although progestin-only pills and medroxyprogesterone acetate injections are safe, they are less effective than long-acting, reversible, and permanent contraceptive options. ERA medications may decrease the potency of hormonal contraceptives[71]. If prescribed to women of childbearing age, dual contraceptive techniques with a mechanical barrier are recommended[30]. Finally, emergency contraception can be considered for instances of unprotected intercourse. Options include a single dose of levonorgestrel (which delays ovulation) or progesterone receptor modulators like mifepristone and ulipristal. These methods are generally considered safe for women with ACHD. However, there may be an interaction between warfarin and high-dose levonorgestrel, so monitoring of the INR is advised[147].

IDENTIFYING AREAS OF IMPROVEMENT

Pfaller et al[148] have found that provider-related factors are responsible for nearly three-quarters of preventable events in maternal and fetal outcomes in women with ACHD. These included accurately identifying and appropriately stratifying ACHD, as well as promptly recognizing and responding to worsening clinical status. This finding indicates that enhanced education of healthcare providers on cardiac risk stratification during pregnancy can significantly reduce adverse events. Davis et al[149] highlighted the necessity for establishing the foundational elements of cardio-obstetrics training. Their proposed framework for training encompasses traditional levels I, II, and III, mirroring competency structures in other cardiology subspecialties. The significant gaps in knowledge regarding how pregnancy influences ACHD and vice versa emphasize the urgent need for more comprehensive research on how ACHD workforce availability influences outcomes for women during pregnancy[150]. A study analyzed the workforce for both pediatric and adult congenital cardiology, emphasizing the need for more trained providers from minority populations in the US to improve disparity in the ACHD workforce[151].

Pregnant women with ACHD are more likely to undergo cesarean delivery, which increases the risk of infection and hemorrhage. Easter et al[152] have reported that planned vaginal births for patients with maternal cardiac disease, offering vaginal delivery with assisted second stage, when necessary, resulted in similar cardiac outcomes but lower rates of postpartum hemorrhage compared to cesarean deliveries. These findings suggest that obstetricians should consider reducing cesarean delivery rates for women with ACHD.

Socioeconomic factors also contribute to adverse maternal outcomes[153]. In the United States, non-Hispanic Black pregnant women tend to experience worse outcomes compared to others[154]. In general, women with ACHD face many public health issues, such as disparities and inequity in care towards racial and ethnic groups, and increasing healthcare costs[155]. The AHA supports federal public policy and legislative actions to improve health outcomes for these vulnerable groups during pregnancy[156]. The Further Consolidated Appropriations Act of 2024 allocated additional funding to the CDC, HRSA, NIH, and SAMHSA to enhance maternal health and reduce the nation's high maternal mortality rate, which has been advocated by ACOG committee since 2021[157]. This includes financial support, health insurance coverage, and subsidies for healthcare services, medications, and medical equipment for women with ACHD during pregnancy[158,159].

Studies have shown that increased diversity in the healthcare workforce, including those who provide care for women with ACHD, leads to improved critical thinking and improved scientific research output[160]. However, like many medical specialties, the ACHD subspecialty has an underrepresentation of women and ethnic minorities relative to their proportions in the United States[161]. Also, there has been a wide disparity in the geographic distribution and access to care by ACHD providers[162].

Restrictions on abortion and abortion pills can have significant implications for pregnancy outcomes in women with ACHD and increase total maternal mortality in the United States[163,164]. On June 24, 2022, the Supreme Court of the United States ruled that the constitution does not confer a right to abortion in Dobbs vs Jackson Women’s Health Organization[165]. This landmark decision overturned the precedent set by United States Supreme Court[166], thus ending federal protection for abortion rights and allowing individual states to dictate abortion access for their residents. Under a complete abortion ban, one model predicts a 53.7% increase in single-ventricle cardiac defects, an additional 9 cases per 100000 Live births[167]. This increase would result in an extra 531 neonatal heart surgeries, 16 heart transplants, 77 extracorporeal membrane oxygenation utilizations, and 102 neonatal deaths annually in the United States. Women with hemodynamically significant ACHD (mWHO class III and IV) usually have high-risk pregnancies that pose significant health risks, including increased strain on the heart, risk of HF, arrhythmias, and death[168]. Overall, abortion bans will significantly affect both pregnancy-related and non-obstetric outcomes for pregnant women, such as mental health[169]. The inability to access abortion in high-risk situations could lead to significant psychological stress, anxiety, and trauma for women with ACHD, particularly if women are forced to continue a pregnancy that jeopardizes their health[170,171]. If the United States bans abortion, maternal mortality associated with pregnancy-related causes is expected to increase 21%, with Black women incurring a 33% increase compared with 13% among White women[172]. Findings demonstrate that black women at all educational levels and those with fewer years of education disproportionately experience adverse birth outcomes associated with restrictive abortion policies. Restrictive abortion policies may compound existing racial/ethnic, socioeconomic, and intersecting racial/ethnic and socioeconomic perinatal and infant health inequities[173]. Policymakers and healthcare systems would need to address these issues to mitigate the potential harm to women with ACHD[174]. This vulnerable population may face increased health risks if they are unable to make informed decisions about their pregnancies based on their individual health needs.

FUTURE DIRECTIONS

Emerging evidence underscores the importance of innovative therapies, such as targeted pharmacological agents and minimally invasive interventions, as well as the development of improved screening methods to identify high-risk patients before ACHD worsens[175].

Non-invasive imaging, telemonitoring, and telehealth

Non-invasive imaging techniques, such as speckle-tracking echocardiography, strain imaging, three-dimensional echocardiography, and CMR, continue to advance and may provide more detailed information about the systemic ventricular function of pregnant women with ACHD, allowing for more accurate risk assessment and management decisions. There have also been notable advancements in fetal cardiac therapy, including transplacental pharmacologic treatments, enzyme replacement therapy, and fetal surgery for specific rare and severe CHD conditions such as hypoplastic left heart syndrome and others[176,177]. Advances in remote monitoring technologies, such as wearable devices and telehealth, provide opportunities for more frequent and convenient monitoring of women with ACHD during pregnancy[178]. Wearable devices, including mobile cardiac telemetry monitoring (MCT), enable earlier detection of potential arrhythmia and facilitate prompt intervention. Rodriguez and colleagues[179] researched to explore whether arrhythmia identified through 24-hour MCT monitoring, either before or early in pregnancy, was linked to negative pregnancy outcomes. Among the 141 pregnancies examined, 17% showed positive MCT findings, underscoring the high prevalence of arrhythmias in the ACHD population. Adverse cardiac outcomes were observed in 11% of the pregnancies, with clinically significant arrhythmia events occurring in 3.5%. Recent innovations in telemonitoring technology have expanded capabilities to assess critical metrics, including HR and its variability, O₂ saturation, CO, and SVR[180]. These enhanced evaluations are particularly valuable for complex ACHD patients experiencing chronic low O₂ levels and BP, as they allow for early detection of potential decompensation and timely intervention[181]. Furthermore, telehealth facilitates routine check-ups and specialist consultations, minimizing the need for in-person visits and improving access to care during pregnancy[182].

Patient education and empowerment

Greater emphasis on patient education and empowerment may become a cornerstone of care for women with ACHD, empowering them to take an active role in their care and make informed decisions. This may involve providing comprehensive education on ACHD, its impact on pregnancy, self-care strategies, and supporting patients in shared decision-making processes related to their care during pregnancy[183].

Role of father

Men can significantly influence supporting and advocating for women during their pregnancy, as they have a critical responsibility in child development[184]. In the mother-and-child dyad, the father's role often takes a backseat. Fathers, however, can serve as essential allies in creating better outcomes for mother and baby, and addressing their needs along the way can improve a family's overall well-being. The importance of family for CV health promotion, focusing on (1) Mutual interdependence of the family system; (2) Shared environment; (3) Parenting style; (4) Caregiver perceptions; and (5) Genomics, contributes to overall improvement in CV health[185]. Family-based approaches that target caregivers and children encourage communication among the family unit and address the structural and environmental conditions in which families live and operate are likely the most effective approaches to promote women’s CV health[186].

CONCLUSION

Many women of childbearing age with ACHD now look forward to successful pregnancies and positive outcomes. However, these women still face a higher risk of cardiac complications during pregnancy and the postpartum period. It is crucial to tailor the management of these pregnancies based on the patient’s specific ACHD, current health status, and other existing comorbidities. Managing pregnancies in women with ACHD should involve a multidisciplinary cardio-obstetrics team, comprehensive patient education beginning with preconception counseling and contraception management, and vigilant monitoring throughout pregnancy and the postpartum period. This approach aims to enhance long-term maternal health and reduce the risk of complications. Furthermore, it is important to address socioeconomic disparities among minority women with ACHD for healthcare access during pregnancy. This requires a multifaceted approach, advocating for policy changes that address disparity in healthcare and implementing targeted interventions to support minority women with ACHD. Future advancements in the care of pregnant women with ACHD should prioritize innovative therapies and refined screening strategies to enable the early detection of complications. By integrating predictive tools and personalized management approaches, healthcare providers can proactively mitigate risks, ultimately improving maternal and fetal outcomes.