Effects of oral glibenclamide versus subcutaneous insulin on perinatal outcome of patients with gestational diabetes mellitus: A randomized clinical trial

Background: The first-line treatment for gestational diabetes mellitus remains insulin, but oral hypoglycemic agents are easier and cheaper to use. The aim of the current study was to compare the efficacy and safety of oral glibenclamide and subcutaneous insulin on the serum glucose control and perinatal outcome of patients with gestational diabetes mellitus. Materials and methods: This randomized clinical trial was conducted during a 2-year period from 2017 to 2019 in two tertiary healthcare centers in Shiraz, Iran. We included 84 singleton pregnancies between 24 and 34 weeks of gestation diagnosed with gestational diabetes mellitus. Patients were randomly assigned to oral glibenclamide (n = 44) or subcutaneous insulin (n =40) according to a standard protocol and followed until delivery. The primary endpoint was to compare the glycemic level of patients, and the secondary outcomes included pregnancy adverse events and neonatal complications such as preeclampsia, preterm and premature rupture of membranes, preterm labor, placental abruption, maternal hypoglycemia, birth weight, neonatal hypoglycemia, hyperbilirubinemia, respiratory distress syndrome, and neonatal intensive care unit admission. Results: The two study groups had comparable baseline characteristics. After treatment, the two study groups were comparable regarding fasting blood glucose (p = 0.398) and 2 h postprandial glucose (p = 0.085). There was no significant difference between the two groups regarding the rate of preeclampsia (p = 0.250), preterm rupture of membranes (p = 0.998), preterm labor (p = 0.495), hypoglycemia (p = 0.476), and abruption (p = 0.815). There was no significant difference between the two study groups in birth weight (p = 0.863) and the Apgar score at 1 (p = 0.190) and 5 min (p = 0.055). The rates of neonatal adverse events including hypoglycemia (p = 0.999), hyperbilirubinemia (p = 0.160), neonatal intensive care unit admission (p = 0.852), and respiratory distress syndrome (p = 0.665) were comparable between the two groups. Conclusion: The results of the current study demonstrate that oral glibenclamide is as effective and safe as subcutaneous insulin in glycemic control and maternal and neonatal outcomes in women with gestational diabetes mellitus. Thus, it could be used as first-line treatment of gestational diabetes mellitus.