Use of oral anti-diabetic agents in pregnancy: a pragmatic approach

Insulin is the gold standard for treatment of hyperglycemia during pregnancy, when lifestyle measures do not maintain glycemic control during pregnancy. However, recent studies have suggested that certain oral hypoglycemic agents (metformin and glyburide) may be safe and be acceptable alternatives. There are no serious safety concerns with metformin, despite it crossing the placenta. Neonatal outcomes are also comparable, with benefit of reductions in neonatal hypoglycemia, maternal hypoglycemia and weight gain, and improved treatment satisfaction. Glibenclamide is more effective in lowering blood glucose in women with gestational diabetes, and with a lower treatment failure rate than metformin. Although generally well-tolerated, some studies have reported higher rates of pre-eclampsia, neonatal jaundice, longer stay in the neonatal care unit, macrosomia, and neonatal hypoglycaemia. There is also paucity of long-term follow-up data on children exposed to oral agents in utero. This review aims to provide an evidence-based approach, concordant with basic and clinical pharmacological knowledge, which will help medical practitioners use oral anti-diabetic agents in a rational and pragmatic manner. Pubmed search was made using Medical Subject Headings (MESH) terms "Diabetes" and "Pregnancy" and "Glyburide"; "Diabetes" and "Pregnancy" and "Metformin". Limits were randomized controlled trials (RCTs) and meta-analysis. The expert reviews on the topic were also used for discussion. Additional information (studies/review) pertaining to discussion under sub-headings like safety during breastfeeding; placental transport; long-term safety data were searched (pubmed/cross-references/expert reviews).