Obstetric considerations

For women with hyperglycaemia in pregnancy (including gestational diabetes), obstetric aspects of care need to be considered. Management should be individualised. No strong evidence-based guidelines on scanning, monitoring fetal wellbeing, or delivery decisions are available for women with hyperglycaemia in pregnancy (including gestational diabetes).

Women with hyperglycaemia in pregnancy at high risk of adverse pregnancy outcomes (eg those with diabetes mellitus in pregnancy, early gestational diabetes, concurrent elevated blood pressure) should have growth and wellbeing scans as for women with pre-existing diabetes (see Obstetric considerations for women with pre-existing diabetes for information about scanning). At the time of writing, most women with hyperglycaemia in pregnancy (including gestational diabetes) have a growth and wellbeing scan at 34 to 36 weeks’ gestation. There is some suggestion that a scan sooner after diagnosis (ie around 30 weeks’ gestation) may identify pregnancies that have the most risk of fetal macrosomia, and possibly of intrauterine growth restriction.

Vaginal delivery is preferred unless there are obstetric reasons for caesarean section. Timing of delivery needs individual consideration; it will usually be aimed for 38 to 40 weeks’ gestation. General recommendations for timing of delivery are:

• delivery around the due date (would occur by 41 weeks’ gestation)—for women in whom glycaemic targets are achieved with diet alone, and without elevated blood pressure or concerns about fetal growth (macrosomia or intrauterine growth restriction)
• early delivery (around 39 weeks’ gestation)—for women in whom glycaemic targets are achieved who are using antihyperglycaemic drugs but have no other complicating factors
• early delivery (more likely to be around 36 to 38 weeks’ gestation)—for women in whom glycaemic targets are not achieved, or those with elevated blood pressure, falling insulin requirements, or a fetus with intrauterine growth restriction or macrosomia.

Women with hyperglycaemia in pregnancy (including gestational diabetes) who require antenatal glucocorticoids to improve fetal lung maturity should be admitted to hospital for glycaemic management. Almost all women, even those in whom glycaemic targets are achieved with diet alone, will require insulin to treat the glucocorticoid-induced hyperglycaemia.