Study finds diabetes drug has no effect on birthweights

A new study led by the University of Edinburgh, in collaboration with the Universities of Warwick, Sheffield and Liverpool, has revealed that treating obese pregnant women with a diabetes drug does not stop their babies from being born overweight.

It had been hoped that the treatment would help to reduce obesity rates and lower the number of difficult births. It is thought that the additional weight gain in the womb is caused by exposure to excess blood sugar.

Heavier babies are more likely to grow into overweight adults. They also have a higher risk of illnesses later in life, such as diabetes and heart disease.

226 obese pregnant women were treated with the diabetes drug metformin — which helps to regulate blood sugar — from the second trimester until their babies were born. There was no difference in the weight of babies born to these mothers compared with a group of 223 women who received a dummy pill. There was also no effect on the number of birth complications, such as miscarriages and still births.

The treatment did help to reduce blood sugar levels in the mothers-to-be. It also helped to lower the levels of other markers that have been linked to pre-eclampsia and premature births.

Heavier babies are more likely to grow into overweight adults. They also have a higher risk of illnesses later in life, such as diabetes and heart disease. The researchers will need to follow the babies involved in the study for longer to determine whether the treatment lowers their chances of developing these health problems.

Professor Jane Norman, director of the Tommy’s Centre for Maternal and Fetal Health at the University of Edinburgh, said: “The children of obese pregnant women face a lifetime of long-term health complications as they grow up. The results of the EMPOWaR study emphasise the importance for women to be of normal weight before pregnancy.”

The research was funded by the Efficacy and Mechanism Evaluation Programme, a Medical Research Council and National Institute for Health Research partnership, and is published in The Lancet Diabetes and Endocrinology.