Overview of pregnancy in women with pre-existing diabetes
The prevalence of pre-existing diabetes in pregnancy is increasing in Australia, primarily because of the increase in type 2 diabetes. Pregnant women with pre-existing type 1 or type 2 diabetes are at greater risk of adverse pregnancy outcomes than women with gestational diabetes or those without diabetes. Obesity has an additional adverse impact on pregnancy outcomes for all women with diabetes.
Most women with pre-existing diabetes have successful pregnancies, despite diabetes increasing the risk of fetal and neonatal mortality and morbidity (eg miscarriage, congenital malformations, macrosomia, neonatal metabolic problems, perinatal death). These complications are at least in part related to glycaemic targets not being achieved before or during pregnancy. Diabetes in pregnancy may also increase the risk of obesity and type 2 diabetes in the offspring in later life. The risk of maternal mortality is increased in women with significant cardiovascular disease or metabolic disturbances such as severe hypoglycaemia or diabetic ketoacidosis. Microvascular complications of diabetes (particularly retinopathy and kidney disease) may progress during pregnancy.
Key aspects of managing women with pre-existing diabetes who are pregnant or planning pregnancy are listed in Key aspects of managing women with pre-existing diabetes who are pregnant or planning pregnancy. Ideally, a woman with pre-existing diabetes should be managed before and during pregnancy by an experienced multidisciplinary team.
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pregnancy |
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all stages of pregnancy |
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optimise the glycaemic profile, while minimising risk of hypoglycaemia screen for and optimise management of complications of diabetes |
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counsel the patient about the importance of planning pregnancy and optimising diabetes management refer for diabetes specialist assessment review all drug treatment and stop drugs that are unsafe in pregnancy start high-dose folate supplementation |
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pregnancy: first trimester |
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refer early to an experienced multidisciplinary team warn the patient of high risk of hypoglycaemia during first trimester (particularly in type 1 diabetes) review all drug treatment and stop drugs that are unsafe in pregnancy; however, do not stop all noninsulin antihyperglycaemic drugs suddenly in early pregnancy arrange nuchal translucency scan |
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pregnancy: second trimester |
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arrange fetal anomaly scan start aspirin (unless contraindicated) and calcium supplementation from 12 weeks gestation for pre-eclampsia prophylaxis (see Other complications of diabetes) |
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pregnancy: third trimester |
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monitor for hypertension and pre-eclampsia obstetric considerations (eg fetal growth, mode and timing of delivery) discuss antenatal breast milk expression stop aspirin at 36 weeks gestation |
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withhold metformin (if taken throughout pregnancy) arrange intravenous access to allow insulin and glucose infusion (if necessary) arrange fetal monitoring if awaiting transfer to a major centre |
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monitor for neonatal hypoglycaemia restart metformin (if withheld at labour) and restabilise other antihyperglycaemic drugs warn the patient about risk of hypoglycaemia during breastfeeding and the postpartum period review safety of drugs used during breastfeeding |