Moderate exercise helps prevent gestational diabetes, reduce weight gain during pregnancy

Gestational diabetes is one of the most frequent complications of pregnancy. It is associated with an increased risk of serious disorders such as pre-eclampsia, hypertension, preterm birth, and with induced or caesarean birth. It can have long term effects on the mother including long term impaired glucose tolerance and type 2 diabetes. The children of mothers with gestational diabetes are more likely to become overweight or obese and have a higher risk of developing diabetes themselves.

Gaining more weight than is recommended during pregnancy carries similar risks, and these women are also less likely to lose the excess weight after the baby is born.

In this systematic review, the research team from Spain looked at the results of enrolling healthy pregnant women, who did little or no exercise, into exercise programmes. Analysis of 13 trials, involving more than 2,800 women, found that exercise reduced the risk of gestational diabetes by more than 30% -- for women who exercised throughout pregnancy this was even greater (36%). This effect was strongest for women who combined toning, strength, flexibility and aerobic exercise.

Exercise was also helpful in reducing excessive weight gain -- those who exercised were on average a kilogram lighter. This held true for the weight gain even if the exercise programme was started in the second trimester of pregnancy.

Gema Sanabria- Martinez, from Virgen de la Luz Hospital and lead author of the study, said, "Exercise is not something to be feared during pregnancy -- the moderate levels of exercise used in these studies had significantly positive effects on health and were found to be safe for both mother and baby."

Mike Marsh, BJOG Deputy Editor-in-chief added, "This careful analysis of previous studies shows a beneficial effect of exercise on healthy pregnant women who ordinarily did little or no exercise. It may influence recommendations for exercise in pregnancy in such women. Further studies are needed to establish whether this effect is seen in all pregnant women."