Metformin therapy and diabetes in pregnancy

■ No adverse pregnancy outcomes with metformin use have been reported, except in one unmatched study. Otherwise, the studies are small and non-randomised, with the exception of one prospective, randomised controlled trial, currently under way, comparing metformin with insulin in women with gestational diabetes mellitus (the MiG trial). No long-term follow-up data for offspring of mothers receiving metformin have been published. ■ Any woman with diabetes should be as close to euglycaemia as possible before pregnancy. ■ In some circumstances (eg, severe insulin resistance), metformin therapy during pregnancy may be warranted. ■ When metformin treatment is being considered, the individual risks and benefits need to be discussed with the patient so that an appropriate decision can be reached.