RENO, NEV. — Metformin controlled blood glucose levels as well as insulin in patients with class A2 gestational diabetes, and was not associated with any adverse maternal or neonatal outcomes, according to a randomized trial with 63 patients.
“We found that metformin appears to be an acceptable way to achieve glucose homeostasis in the A2 diabetes patient,” Christian Briery, M.D., said at the annual meeting of the Society for Maternal-Fetal Medicine.
The study enrolled pregnant patients who were at greater than 11 weeks' gestation but less than 35 weeks' gestation. The women received a starting dose of insulin of 0.7 U/kg daily, in three doses (31 patients) or 500 mg metformin twice daily (32 patients).
The patients were then monitored weekly to see that they achieved a postprandial blood glucose level of less than 120 mg/dL and a fasting glucose level of 60-90 mg/dL, said Dr. Briery of the University of Mississippi Medical Center, Jackson.
In blood glucose measurements taken by the patients at home, the mean fasting glucose level was 96.8 mg/dL in the insulin-treated patients versus 92.6 mg/dL in the metformin-treated group.
Similarly, the researcher reported that the mean postprandial glucose levels ranged in the insulin group from 104.4 mg/dL 2 hours after breakfast to 112.5 mg/dL 2 hours after lunch. The mean postprandial glucose levels in the metformin group ranged from 104.6 mg/dL 2 hours after breakfast to 108.1 mg/dL 2 hours after dinner.
The maternal and delivery measures considered included abdominal delivery, gestational age at delivery, shoulder dystocia, and postpartum hemorrhage.
There was no difference in those measures between the groups.
There was one intrauterine fetal death in the metformin group from a “cord problem” that was determined not to be related to treatment because the mother's glucose levels were consistently normal, Dr. Briery said.
Neonatal outcomes that were considered in the trial include birth weight, 5-minute Apgar score, respiratory distress syndrome, neonatal hypoglycemia, and neonatal ICU admission. Again, the researcher said there was no difference among the groups.
A previous study of metformin use during pregnancy looked specifically at patients who had polycystic ovary syndrome and who conceived while taking the drug. That investigation likewise found no indication of any adverse effects that might normally be associated with the agent.