Comparison of metformin versus other treatment modalities in gestational diabetes mellitus

Abstract

INTRODUCTION: Despite evidence to prove both its efficacy and safety, use of metformin is at most restricted to only as an adjunct to insulin preparations. We compared the maternal, fetal and neonatal outcomes associated with GDM in women treated with metformin versus those treated with diet alone and diet plus insulin. Method: An observational study was carried out over a period of six months in 104 GDM patients. Study groups were 43 patients on diet alone (group A), 42 on metformin plus diet (group B), and 19 on diet plus insulin (group C). Maternal, fetal and neonatal outcomes were compared. Results: Fourteen patients in group B subsequently required supplemental insulin. Gestational hypertension 5(12%), 4(10%), 5(26%) (p=0.8) and wound infection among 2(5%), 1(2%), 0(0%) (p=0.6) were seen in groups A, B and C respectively. Four patients with polyhydramnios were seen in group B. Mean birth weights were A=3.07kg, B=3.07kg, C=3.1kg (p=0.96). Macrosomia 5 (12%), 3 (7%), 3 (16%) (p=0.2), neonatal hypoglycemia 2 (5%), 2 (5%), 2 (11%) (p=0.4), five minute Apgar scores 9.9, 9.7, 9.9, and neonatal jaundice 5(12%), 4(10%), 3(16%) (p=0.04) were noted in in groups A, B and C respectively. Single case of respiratory distress was seen in the insulin group. Shoulder dystocia and perinatal deaths were not observed. Conclusion: Maternal and perinatal outcomes were similar among diet alone, diet plus metformin, and diet plus insulin groups. Cost-effectiveness, easy administration, safety profile and convenience of storage would make metformin an attractive option in the management of gestational diabetes mellitus.