Metformin does not reduce birth weight in obese mothers

The diabetes drug metformin does not reduce the likelihood of an obese women without diabetes having an overweight baby, according to a new study.
The complication of excessive birth weight – also known as macrosomia – commonly affects women who give birth while obese.
There can be excessive blood glucose in the wombs of obese pregnant women, making them significantly more insulin resistant and hyperglycemic than pregnant women of a normal weight.
Researchers at the University of Edinburgh therefore examined if metformin – which lowers blood glucose levels – could reduce the weight of the babies from obese women.
In the EMPOWAR trial, which was conducted across 15 NHS hospitals in the United Kingdom, metformin was given to 226 women from their second trimester until the birth of their baby, while 223 women were given a placebo.
No significant differences were observed in the birth weight of the children. The mean birth weight was 3463g in the placebo group and 3462g in the metformin group.
Metformin did lower the blood glucose levels of the pregnant women, but did not have an effect on the number of birth complications, such as stillbirths and miscarriages.
The researchers hope that follow-up studies on the babies will determine if metformin affects health outcomes in the long-term.
Jane Norma, director of the Tommy’s Centre for Maternal and Fetal Health at the University of Edinburgh in Scotland, said: “The children of obese pregnant women face a lifetime of long term health complications as they grow up. The results of [this] study emphasise the importance for women to be of normal weight before pregnancy.”
The results of this study were published in The Lancet Diabetes and Endocrinology.