diabetes and pregnancy

Gestational diabetes now includes both gestational impaired glucose tolerance and gestational diabetes mellitus.

Approximately 1 in 400 pregnancies are complicated by diabetes. 95% of diabetic mothers are insulin dependent.

Most cases of diabetes in pregnancy are seen in patients who were diabetic before conception.

Women who develop diabetes during pregnancy are said to have gestational diabetes. Some will remain diabetic after delivery of the foetus while others will revert to apparent normality. The detection of gestational diabetes is described (1):

• if glycosuria is detetected then a casual timed plasma venous glucose estimation should be performed and interpreted as below
  • a 75 g oral glucose tolerance test (OGTT) should be performed if the random plasma venous glucose concentrations are not diagnostic but are >6.1 mmol/l in the fasting state or more than 2 hours after food or >7.0 mmol/l within 2 hours of food
• diagnosis should be made if fasting venous plasma glucose is >7.0 mmol/l or fasting venous plasma glucose is <7.0>7.8 mmol/l 2 hours after a 75 g glucose load

Before insulin was available, the perinatal mortality associated with diabetes approached 50%. Over the last 60 years, this horrific figure has been reduced to 2% in the best units. Nevertheless perinatal mortality amongst the babies of diabetics is still several times higher than amongst the general population and so continued attention must be paid to the well being of these patients through pregnancy.

At 6 weeks or more postpartum, diabetes UK suggest that a further oral glucose tolerance test should be undertaken in women diagnosed with gestational diabetes (whether or not the patient still has impaired glucose tolerance or impaired fasting glycaemia). These women, whatever the result of the oral glucose tolerance test, are at an increased risk of developing diabetes later in life.

• advice from the UK National Screening Committee on antenatal screening for diabetes..click here

NICE however suggest that (2)

• women who were diagnosed with gestational diabetes should be offered lifestyle advice (including weight control, diet and exercise) and offered a fasting plasma glucose measurement (but not an oral glucose tolerance test) at the 6-week postnatal check and annually thereafter

The management of women with diabetes (Type 1 or Type 2) who become pregnant is described in the linked items in the menu below.

Reference:

• (1) Diabetes UK. Recommendations for the management of pregnant women with diabetes (including gestational diabetes). 2003
• (2) NICE (March 2008). Diabetes in pregnancy Management of diabetes and its complications from pre-conception to the postnatal period