Type 2 diabetes and pregnancy

The management of pregnancy in a woman with type II diabetes requires specialist advice preconceptually and during pregnancy.

The summary of guidance from Diabetes UK regarding the management of pregnancy in women with Type 2 diabetes is presented below (1):

• women on oral hypoglycaemic agents or whose HbA1c is above normal should be started on insulin before conception;oral hypoglycaemic therapy should be stopped
• those not attending for pre-pregnancy counselling should be started on insulin as early as possible if preprandial blood glucose levels exceed 6.0 mmol/l, or if HbA1c is elevated
  • oral agents should be stopped as soon as pregnancy is confirmed
• management should then be as for women with Type 1 diabetes

There is evidence relating to maternal and neonatal complications in pregnancies of diabetic women treated with oral hypoglycaemic agents (2):

• a cohort study including all consecutively registered, orally treated pregnant diabetic patients set in a diabetic obstetrical service at a university hospital
  • 50 women treated with metformin, 68 women treated with sulphonylurea during pregnancy and a reference group of 42 diabetic women treated with insulin during pregnancy
  • the prevalence of pre-eclampsia was significantly increased in the group of women treated with metformin compared to women treated with sulphonylurea or insulin (32 vs. 7 vs. 10%, P < 0.001)
  • no difference in neonatal morbidity was observed between the orally treated and insulin-treated group; no cases of severe hypoglycaemia or jaundice were seen in the orally treated groups. However, in the group of women treated with metformin in the third trimester, the perinatal mortality was significantly increased compared to women not treated with metformin (11.6 vs. 1.3%, P < 0.02)
• the authors concluded that treatment with metformin during pregnancy was associated with increased prevalence of pre-eclampsia and a high perinatal mortality

There is evidence comparing the outcomes of pregnancies in women with type II diabetes with pregnancies in the general population (3):

• hypertension/pre-eclampsia was two times, polyhydramnios three times, and postpartum haemorrhage six times more common than in non-diabetic women
• the authors concluded that women with Type 2 diabetes have a less satisfactory pregnancy outcome compared with the general population. Infants have a two-fold greater risk of stillbirth, a 2.5-fold greater risk of a perinatal mortality, a 3.5-fold greater risk of death within the first month and a six-fold greater risk of death up to 1 year compared with regional/national figures. The children had an 11 times greater risk of a congenital malformation

Reference:

1. Diabetes UK. Recommendations for the management of pregnant women with diabetes (including gestational diabetes). 2003
2. Diabet Med. 2000 Jul;17(7):507-11.
3. Diabet Med. 2003 Sep;20(9):734-8.