Pregnant women with diabetes 'need extra care'

6th February 2012 - The risk of delivering a baby with a birth defect increases by nearly four-fold for women with diabetes compared to those without the condition, according to a new study.

The authors say the extra risk appears to be linked to the mother's blood glucose levels and that pregnant women with diabetes should be given extra care to increase their chances of giving birth to a healthy baby.

The study, led by researchers at Newcastle University and the Regional Maternity Survey Office suggests that as many as one in 13 deliveries to women with Type 1 or Type 2 diabetes involves a birth defect, otherwise known as a major congenital anomaly.

The researchers examined data from 401,149 singleton pregnancies from the north-east of England, 1,677 of which involved pregnant women with diabetes. The analysis showed that the risk of a birth defect in the pregnancies of women with Type 1 or Type 2 diabetes was 7%, compared to an average of around 2% in pregnancies where the mother did not have diabetes.

Blood glucose control

Previous research has established that having diabetes increases the chance of birth defects, but the latest study, published in the journal Diabetologia, is one of the first to quantify the effect of glucose levels on risk.  

Existing guidelines emphasise the need for specialist care before a woman with diabetes gets pregnant. This includes advice about establishing good control over their blood glucose levels before conception and a warning about the risk of unplanned pregnancy. Women should also be told that the risk of miscarriage, congenital malformation, stillbirth and neonatal death can be reduced but not entirely eliminated. 

The guidelines say that women thinking about getting pregnant should maintain their long-term blood- glucose levels at below 6.1%. At this level, the latest research found that the risk of birth defects was one in 34. The risk rose to one in six for a woman with 12.5% blood glucose levels. 

Preparing for pregnancy

Dr Ruth Bell, the study’s lead researcher, said in a statement: "The good news is that, with expert help before and during pregnancy, most women with diabetes will have a healthy baby. The risk of problems can be reduced by taking extra care to have the best possible glucose control before becoming pregnant. Any reduction in high glucose levels is likely to improve the chances of a healthy baby. 

"All young women with diabetes need to know about preparing for pregnancy, and should contact their doctor or diabetes team as soon as possible if they are thinking about pregnancy or become pregnant." 

Dr Iain Frame, director of research for Diabetes UK which funded the study, said in a statement: "This study offers clear evidence that although women with diabetes might still have a higher risk of a birth defect, they can still do something positive to reduce that risk by carefully monitoring their blood glucose level and trying to reduce it if it is high. 

"We need to get the message out to women with diabetes that if they are considering becoming pregnant, then they should tell their diabetes healthcare team, who will make sure they are aware of planning and what next steps they should be taking. Blood glucose control continues to be important throughout pregnancy and should be closely monitored to ensure the best result for the baby: this is why women should be as prepared as possible beforehand."