Maternal and Fetal Outcome in Gestational Diabetes Mellitus (GDM) Treated with Diet and Metformin - A Preliminary Retrospective Analysis

Context: Metformin therapy for treatment of GDM (Gestational Diabetes Mellitus) is not yet approved by FDA. Objectives: To assess the glycaemic control in women with GDM who received metformin therapy and to know the maternal side-effects and effects on the fetus-neonate. Material and Methods: A preliminary retrospective cohort analysis of 38 women with GDM who received metformin along with dietary advice for control of GDM. The maternal analysis included the time of initiation of metformin therapy, the glycaemic control, the need to add insulin and the side-effects. Fetal outcome analysis included Apgar score at birth, birth weight, neonatal hypoglycaemia, still birth rate and congenital malformations. The goals of glycaemic control were achieved by a pre-prandial Blood sugar of 60-70 mg%; post prandial blood sugar of 120-140mg%. Results: The mean age was 27.5 years and gestational age at diagnosis and initiation of metformin therapy was 24 weeks and 3 days. Twenty-four percent were diagnosed during first trimester. Ninety percent achieved glycaemic control with a dose of 1500 mg of metformin. Ten percent required an increment in dose up to 2250 mg and an addition of small dose of insulin only after 35 weeks of gestation. The mean birth weight was 3.12 kg and 13% were LGA. There were no cases of maternal or neonatal hypoglycaemia and no stillbirths, congenital anomalies or neonatal deaths. Conclusion: Metformin therapy resulted in optimum control of blood sugar in most of the women with GDM without any significant side-effects in the mother or in the fetus-neonate.