Review
Copyright ©2012 Baishideng. All rights reserved.
World J Obstet Gynecol. Oct 10, 2012; 1(3): 29-34
Published online Oct 10, 2012. doi: 10.5317/wjog.v1.i3.29
Free radicals generation in an in vitro fertilization setting and how to minimize them
Fanuel Lampiao
Fanuel Lampiao, Department of Basic Medical Sciences, Division of Physiology, College of Medicine, P/Bag 360, Blantyre 3, Malawi
Author contributions: Lampiao F solely contributed to this paper.
Correspondence to: Fanuel Lampiao, PhD, Department of Basic Medical Sciences, Division of Physiology, College of Medicine, P/Bag 360, Blantyre 3, Malawi. flampiao@medcol.mw
Telephone: +265-111-677245 Fax: +265-111-674700
Received: March 23, 2012
Revised: June 20, 2012
Accepted: September 12, 2012
Published online: October 10, 2012
Abstract

Several studies report an increase in both male and female factors in infertility worldwide. In recent years there has been a tremendous increase in couples seeking assisted reproductive technology (ART) procedures in order to have children. However, the success rates of these procedures still remain very low. One of the major contributing factors to the low success rate in ART has been the damage caused by free radicals to the gametes and the developing embryo. The manipulation of gametes and embryos in an in vitro environment when performing assisted reproductive techniques carries the risk of exposure of these cells to supraphysiological levels of free radicals; namely, reactive oxygen species (ROS) and reactive nitrogen species. Oxidative stress can originate from the early steps of ART involving the oocyte, sperm and embryo, as well as in the endometrial environment later on following embryo transfer. The common sources of free radicals in an in vitro fertilization setting include the developing embryo, spermatozoa and leukocytes, semen centrifugation, oxygen partial pressure, light, culture media and cryopreservation/thawing. These free radicals are measured using different techniques, such as the cytochrome C reduction method and chemiluminescence-based techniques. Different efforts are being employed to minimize the excess generation of free radicals in the ART setting, with the aim of improving the success rate, and antioxidant supplementation has emerged as one of the viable routes. Moreover, it is very important to inform ART personnel about the sources of ROS in the laboratory so that they can stop the use of procedures that are deleterious and start to use safer procedures.

Keywords: Reactive oxygen species; Oxidative stress; Assisted reproduction; Spermatozoa; Ovum; Antioxidants