Oral hypoglycaemic agents for diabetes in pregnancy - an appraisal of the current evidence for oral anti-diabetic drug use in pregnancy.

Introduction: The use of oral hypoglycaemic drugs in pregnancy is not recommended because of reports of foetal anomalies and other adverse outcomes in animal studies and in some human cases. However, recent studies have suggested that some oral hypoglycaemic drugs may be used in pregnancy. This review will examine these studies critically.

Methods: Literature review of articles obtained from a PubMed search of peer-reviewed journals on oral hypoglycaemic drug use in pregnancy.

Results: In two prospective studies, one of which was a randomised controlled trial, glibenclamide was as effective and safe as insulin in gestational diabetes. In several studies, metformin did not increase foetal anomalies or malformations when used during pregnancy in women with polycystic ovary syndrome (PCOS). In one prospective study on infants born to mothers who used metformin in pregnancy, follow-up for 18 months showed no adverse effects. In several prospective and retrospective studies on women with PCOS, metformin was shown to prevent early pregnancy loss, decrease insulin resistance, reduce insulin and testosterone levels, and decrease the incidence of gestational diabetes when these women got pregnant while on metformin and continued to take it throughout their pregnancy. In a single small study, acarbose did not cause any adverse effects during pregnancy.

Conclusions: Recent evidence shows promising findings in the safety and efficacy of some oral hypoglycaemic agents in treating pregnant diabetics. However, larger clinical studies will be needed to ensure the safety and efficacy of these drugs in pregnancy.