Metformin in Women with Type 2 Diabetes in Pregnancy (Mity): A Multicentre, International, Randomized, Placebo-Controlled Trial
Metformin is a more frequently prescribed drug. Despite previous researches, there is a lack of existing evidence to guide clinicians for the use of metformin along with insulin in pregnant women with type 2 diabetes. Feig and Colleague (2020) conducted a multi-centre, international, randomized, placebo-controlled trial to study “Effect of metformin in women with type 2 diabetes” published in The Lancet Diabetes and Endocrinology Journal. A summary of the findings can be studied below:
Objectives:
To study the effect of metformin administration with standard insulin regime on neonatal mortality and morbidity in pregnant women with type 2 diabetes. To study several maternal and neonatal outcomes.
Method:
Women with type 2 diabetes during pregnancy were selected at 25 centers in Canada and four centers in Australia. They were randomly assigned with metformin 1000 mg twice daily or placebo, along with insulin. Participants were instructed to check fasting blood glucose levels before the first and last meal of the day, 2h after each meal. Follow up visit was conducted on monthly basis. Insulin dosage was recommended to meet the target glucose level.
Findings:
This was the first large methodologically appropriate randomized trial of its kind. No difference was reported in neonatal mortality and morbidity between women receiving metformin and placebo. On the other hand, lower insulin requirement, fewer cesarean birth, better glycemic control, and less gestational weight gain were reported in women on metformin. A high proportion of infants were small for gestational age in the metformin receiving group. These infants are at higher risk of perinatal complications as per previous researches. The study reports no serious neonatal outcome when metformin is combined with insulin. The use of metformin can be a cost-saving approach for women belonging to the lower-income populations because this drug reduces insulin dose by 45 units per day.
Limitations:
The cause for newborns in the metformin group having small gestational age is unknown. The authors suggest that the study might not apply to 15% of women who are treated with metformin alone. To open up broader understanding, authors suggest a future study to cover the development of children in the metformin group till their adulthood.