Prevention of hyperglycaemia in pregnancy (including gestational diabetes) in subsequent pregnancies

The increasing prevalence of obesity in women is contributing to the increased incidence of hyperglycaemia in pregnancy (including gestational diabetes) and can be addressed before pregnancy. Optimising a woman’s weight before pregnancy should be strongly encouraged. Losing weight can improve fertility and may reduce the risk of developing gestational diabetes. However, rapid weight loss before conception can lead to rapid weight gain in early pregnancy. Ideally, the woman’s weight should be stable before pregnancy and care should be taken in early pregnancy to avoid rapid weight gain.

At the time of writing, lifestyle interventions (dietary intake and physical activity) during pregnancy to prevent gestational diabetes have shown little or no benefit. Therefore, the focus is on lifestyle interventions before and between pregnancies.

Bariatric surgery can result in significant weight loss for women with class II or class III obesity. It may reduce rates of gestational diabetes, large-for-gestational age babies and pre-eclampsia in subsequent pregnancies. However, there have been reports of increased rates of small-for-gestational age babies, and possibly maternal venous thromboembolism and perinatal mortality in women who have had bariatric surgery. Women who have had bariatric surgery should wait 12 months before trying to conceive. They should take multivitamins and have their blood concentrations of iron, vitamin B₁₂ and vitamin D checked.