Gestational diabetes explained

​Gestational diabetes (GDM) is diabetes which develops during pregnancy. It is a very common condition with about 10-15% of women developing GDM during their pregnancy. GDM usually starts in the second half of the pregnancy especially, generally after 20 completed weeks. Pregnant women with GDM will have abnormally raised bloods sugars.

All pregnant women are tested for GDM at 24 to 28 weeks. Women with a high-risk of developing GDM are tested as early as 12 weeks. We recommend testing for GDM with the Oral Glucose Tolerance Test (OGTT). The previous screening test, Glucose Challenge Test (GCT), should not be used unless there are special conditions.

Women diagnosed with GDM are instructed to follow a strict diet and exercise program. In some cases, to enable optimal control of blood sugars, some women may be required to take tablets or have insulin injections. Tablets are the preferred approach as research has shown that pregnant women are generally more compliant with taking tablets that having to inject insulin.

There are several increased risks factors for pregnant women with diabetes, with 30 from 100 women having larger than average babies. GDM pregnancies are more likely to require some form of intervention in labour and are an increased risk for having a caesarean section delivery.

It is recommended that women with GDM start expressing and storing breast milk from 36 weeks of gestation. For women with GDM who require medication or injections, induction of labour at 38 – 39 weeks of gestation is recommended. Women with GDM who have controlled bloods sugars with diet alone, induction of labour at 39-40 weeks is recommended.

Research has shown that the women with GDM are at increased risk of developing GDM in the future pregnancies and developing type 2 diabetes later in life.
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All women with GDM should have a repeat 75 gr GTT at 6 weeks post-delivery to confirm that the bloods sugars have returned to normal.