News

23rd April 2004

Weight loss before pregnancy may reduce risk of pre-eclampsia

Achieving a healthy weight before becoming pregnant may reduce the likelihood of developing the pregnancy condition pre-eclampsia, says new research from the US.

Scientists at the Magee Women's Research Institute in Pittsburgh studied nearly 1200 pregnant women to try to discover what factors increase the likelihood of developing the condition, which affects up to one in 10 pregnancies in the UK.

Pre-eclampsia - or pregnancy-induced hypertension - is characterised by high blood pressure, protein in the urine and swelling of the hands, feet and face. It develops because of problems in the placental blood supply and causes reduced blood flow to both mother and baby. If it is not carefully monitored, pre-eclampsia may become very serious and is a major cause of premature birth.

All the women in the study were expecting their first baby and when the research team assessed all the elements that may have affected the likelihood of participants developing the condition, one main factor stood out - their pre-pregnancy weight. The results showed that the higher a woman's body mass index (a calculation of body weight in relation to height) before pregnancy, the more likely she was to develop pre-eclampsia.

Researchers found that risk of pre-eclampsia rose sharply with increased pre-pregnancy body weight, with women who were considered obese being three times as likely to develop the condition as women with a normal body weight.

One of the scientists, Dr Lisa Bodnar, said that the most surprising finding was that women who were considered underweight before pregnancy were only half as likely to develop pre-eclampsia as women whose weight was within the normal range.

She said the results of the study indicate that fat tissue itself is playing a role in the development of pre-eclampsia, and went on to comment that understanding how the relationship between body fat and pre-eclampsia works could help scientists find ways to treat the condition.

For women planning a pregnancy, these findings suggest that it's important to be within the normal weight range before becoming pregnant if possible. However, while the study indicates that losing weight before becoming pregnant may help reduce the risk of pre-eclampsia, the researchers stress that weight loss during pregnancy is inadvisable.

• How will I know if I'm at risk of pre-eclampsia? Find out here
• Have you experienced pre-eclampsia? Tell us your story in Your shout