Diabetes alternative "safe" for pregnant women: study

An alternative treatment to insulin injections for pregnant women with gestational diabetes has been shown as safe and effective in a new trial led by researchers in Adelaide and Auckland.

A clinical trial of 751 women with gestational diabetes in Australia and New Zealand compared two treatments: insulin injections, and the oral anti-diabetic drug metformin.

The results of the trial, published in The New England Journal of Medicine, show that the babies of mothers treated with metformin were no different from the babies of mothers treated with insulin alone, either at birth or at 6-8 weeks of age.

"No serious adverse effects were associated with the use of metformin," said University of Adelaide Clinical Senior Lecturer Dr Bill Hague (Discipline of Obstetrics & Gynaecology).

"More than half the women taking metformin could be managed with tablets alone. If extra insulin was necessary, the dose was less than that required for women taking insulin alone," he said.

Gestational diabetes is a complication in about 5% of pregnancies and is on the increase. Where the diabetes can't be controlled through diet and exercise, insulin therapy is often used to significantly improve the health outcomes for both baby and mother.

"But the use of insulin requires injections and women need to be educated in its use," Dr Hague said. "Insulin therapy can also cause low blood glucose and weight gain in the mother, whereas use of metformin usually returns blood glucose to normal, rather than dropping it too low, and is also associated with maternal weight loss.

"Oral medication therefore can offer considerable advantages. Women in this trial certainly preferred to use metformin rather than insulin.

"To date, however, metformin use in pregnancy remains controversial - before this study there were only two reported small randomised trials comparing metformin with insulin," he said.

Dr Hague said the children born within this trial were currently being assessed at two years of age, and further follow-up data were needed to establish long-term safety.