Maternal and neonatal outcomes according to the timing of diagnosis of gestational diabetes: A critical appraisal

Table 2 Design of studies comparing of adverse pregnancy outcomes between women having early gestational diabetes and late-onset gestational diabetes

Ref.	Study time	Country	Study design	GDM diagnostic criteria	Adverse outcomes assessed in the study, statical methodology, confounding factors
Feghali et al[31]	January 2009 to October 2012	United States	Retrospective study; PGDM excluded; E-GDM < 24 GW, n = 167; L-GDM ≥ 24 GW, n = 1202; routine GDM care to all	Two step screening using; C & C criteria for both E-GDM and L-GDM; risk-based E-GDM screening	Macrosomia, preterm delivery, gestational hypertension, neonatal morbidity, conditional logistic regression analysis, reference L-GDM, confounding factors; maternal age, maternal race, education, private insurance, nulliparity, prepregnancy BMI, tobacco use, GDM history, 50 g glucose challenge test value, reference L-GDM
Shub et al[32]	January 2005 to January 2016	Australia	Retrospective study; PGDM exclusion: Not mentioned; E-GDM < 20 GW, n = 170; L-GDM ≥ 20 GW, n = 171; no GDM, n = 547; routine GDM care to all	One step screening; same criteria for E-GDM and L-GDM; till 2013: FPG ≥ 5.5 mmol/L, or 2-hour PG ≥ 8 mmol/L. From 2014: IADPSG criteria, risk-based E-GDM screening	Composite obstetric outcome (caesarian, macrosomia, LGA, perineal tear, shoulder dystocia), composite neonatal outcomes (Apgar < 7 at 5 minutes, NICU admission, neonatal hypoglycemia, major birth defect). Multivariate logistic regression, reference “no GDM”. Confounding factors; maternal age, BMI, parity and region of birth
Punnose et al[33]	January 2011 to September 2017	India	Retrospective study; PGDM excluded; E-GDM < 24 GW, n = 255 (< 14 GW, n = 125, 14-23 GW, n = 130); L-GDM ≥ 24 GW, n = 467; routine GDM care to all	One step screening by IADPG criteria for both E-GDM and L-GDM; risk-based E-GDM screening	Premature birth, caesarian delivery, LGA babies, NICU admission, gestational hypertension, induction of labor, macrosomia, Apgar < 7 at 1 or 5 minutes. Multivariate regression analysis, reference “no-GDM”. Confounding factors; age, gravida, gestational age at delivery (except for premature delivery and LGA babies), hemoglobin, socioeconomic level, education, hypertension in pregnancy (except for gestational hypertension), BMI
Yefet et al[34]	August 2005 to January 2018	Israel	Retrospective study; PGDM excluded; study groups, GDM < 14 GW (T1), n = 117, GDM 14-23 GW (T2), n = 116, GDM ≥ 24 GW (T3), n = 2334. Also grouped as E-GDM < 24 GW, n = 233, L-GDM ≥ 24 GW, n = 2334; routine GDM care to all	Two step screening; C & C criteria or NDDG criteria for E-GDM and L-GDM. Risk based E-GDM screening	Composite neonatal outcomes (LGA babies, neonatal hypoglycemia, neonatal hyperbilirubinaemia. Other outcomes: Preterm birth, shoulder dystocia, birth trauma, foetal malformations. Multivariable logistic regression analysis, reference L-GDM. Confounding factors: Type of GDM control (A1 with diet alone, A2 with medications, age, BMI, parity, delivery week
Tirado-Aguilar et al[35]	January 2022 to May 2023	Mexico	Prospective study; PGDM excluded; E-GDM < 24 GW, n = 173; L-GDM 24-28 GW, n = 196; routine GDM care	One step screening, IADPSG for both E-GDM and L-GDM groups. Universal OGTT at first prenatal visit, if negative repeat screening 24-28 GW	Gestational hypertension, neonatal hypoglycemia, respiratory distress syndrome, neonatal asphyxia, neonatal hyperbilirubinaemia, mechanical ventilation, neonatal death. Logistic regression model analysis, reference L-GDM. Confounding factors; maternal age, pregestational BMI
Regnault et al[28]	2018 French National Health Data	France	Retrospective study; PGDM excluded from GDM; 84705 women with hyperglycemia in pregnancy. GDM < 22 GW, n = 31134; GDM 22-30 GW, n = 44412; GDM > 30 GW, n = 8789; no GDM treatment details	Before 24 GW: FPG ≥ 5.1 mmol/L. > 24 GW: IADPSG criteria	Maternal outcomes: Caesarian, pre-eclampsia, ante and post-partum hemorrhage. Neonatal outcomes: Perinatal death, congenital malformations, LGA, Erb’s palsy and calvicular fracture, foetal distress, NICU admission, neonatal hypoglycemia preterm delivery. Multilevel Poisson regression analysis, reference l-GDM. Confounding factors; maternal age, socioeconomic status, and gestational age of delivery except for preterm delivery

PGDM: Pregestational diabetes mellitus; E-GDM: Early-onset gestational diabetes; L-GDM: Late-onset gestational diabetes; GDM: Gestational diabetes mellitus; GW: Gestational weeks; BMI: Body mass index; FPG: Fasting plasma glucose; PG: Plasma glucose; IADPSG: International Association of Diabetes in Pregnancy Study Group; LGA: Large for gestational age babies; NICU: Neonatal intensive care unit; BMI: Body mass index; C & C criteria: Carpenter and Coustan criteria; T1: First trimester; T2: Second trimester; T3: Third trimester; NDDG: National Diabetes Data Group; OGTT: Oral glucose tolerance test.