Three therapies used for glycaemic control in women with gestational diabetes (GDM) have differing effects on the baby’s birth weight, a meta-analysis shows.

Researchers from the University of Cambridge, UK, analysed 33 trials including almost 5000 women with gestational diabetes randomised to metformin, insulin or glibenclamide.

Women randomised to glibenclamide had babies that were 58g heavier on average than those randomised to insulin and 191g heavier than those treated with metformin, the results showed.

Meanwhile, compared with women treated with insulin, those treated with metformin had babies weighing a mean of 74g less at birth, the authors reported in PLOS Medicine.