A Norwegian study has shown that low impact aerobics could not only assist pregnant women in staying healthy, but also help to prevent their newborn baby being overweight.

A heavier birth weight (known as fetal macrosomia) increases risk for both mother and baby. In newborns with a weight of more than 8.8 pounds (4kg), the risk of delivery problems, C-sections, postpartum haemorrhage and low Apgar scores (a simple method of quickly assessing the health of newborns) increase. Links between heavier birth weights and obesity later in life have also previously been drawn.

Data from the Norwegian Mother and Child Cohort study, which included information on nearly 37,000 women, was used. Two-thirds of the subjects were of normal weight, while 20 per cent were classified overweight, but not obese.

Babies birth weights did not seem to be affected by pre-pregnancy exercise, just by that during pregnancy. The researchers found that in women who were pregnant for the first time and who regularly exercised during their second and third trimesters had up to 28 per cent lower chance of giving birth to a ‘too-big’ baby. Expectant mothers who were still working out regularly at the 30-week stage had a 23 per cent lessened risk of delivering a too-big baby.

Commenting on the findings, Dr Robert Welch, chairman of obstetrics and gynaecology at Providence Hospital in Southfield, Michigan, said, ‘Women often adopt healthier habits before and during pregnancy, like stopping caffeine use. This study suggests that adding exercise to that list may be icing on the cake’.

The results seemed to show that pregnant women who had already had previous children did not achieve the same level of benefit through exercise, although low-impact aerobics appeared to reduce the likelihood of having a too-large baby.

Welch advised that in more progressed stages of pregnancy women should not do any exercise which involves laying flat on their back, as this position can restrict blood flow to mother and baby. He also advises that pregnant women keep their heart rate to below 120bpm, which provides an aerobic workout without negatively affecting blood flow.

Source: Obstetrics and Gynecology