Safety of Insulin Glargine Use in Pregnancy

The prevalence of diabetes in women of childbearing age is increasing. As such, the number of pregnancies complicated by diabetes will inevitably increase. New insulin analogues such as the long-acting analogue insulin glargine may represent beneficial treatment options in pregnancy by ensuring that patients achieve excellent glycemic control without risk of maternal hypoglycemia.

The study was done to determine the fetal safety of insulin glargine use in the treatment of diabetes in pregnancy compared with NPH insulin therapy.

A systematic review and meta-analysis was performed of all original human studies that reported neonatal outcomes among women with pregestational or gestational diabetes who were managed with either insulin glargine or NPH insulin during pregnancy. A systematic literature search was conducted from 1980 to June 1, 2010. Outcomes included large size for gestational age, macrosomia, neonatal hypoglycemia, neonatal intensive care unit admissions, birth trauma, congenital anomalies, preterm delivery, perinatal mortality, respiratory distress, and hyperbilirubinemia. Relative risk ratios and weighted mean differences were computed with 95% confidence intervals.

Eight studies reporting on a total of 702 women with pregestational or gestational diabetes in pregnancy treated with either insulin glargine (n = 331) or NPH insulin (n = 371) met the inclusion criteria. There were no statistically significant differences in the occurrence of fetal outcomes studied with the use of insulin glargine compared to NPH insulin.

Several new insulin analogues have become available during the past decade, yet data on the fetal safety of insulin glargine are scarce. By avoiding high peaks in insulin concentrations, insulin glargine may be beneficial in diabetic pregnancies where both tight glycemic control to reduce fetal complications and the prevention of maternal hypoglycemia are imperative. In a meta-analysis of 8 studies, we found no statistically significant increased risk for any of the fetal outcomes studied. In addition, there were no statistically significant differences in mean gestational age at birth or in birth weight between patients treated with either glargine or NPH insulin in women with pregestational diabetes, gestational diabetes, or combined cohorts.

In summary, the systematic review and meta-analysis did not detect an increase in the incidence of adverse fetal outcomes with the use of insulin glargine in pregnancy when compared with NPH insulin. These results have important clinical implications for the use of insulin glargine in pregnancy and will potentially improve the options for women, with diabetes in pregnancy, who wish to achieve excellent control of their glucose levels without the fear of adverse fetal complications.

The Annals of Pharmacotherapy. 2011;45(1):1-8