Mother’s exercise may have long term benefits for children

A study by researchers at the Liggins Institute has shown that women who maintained regular, moderate, aerobic exercise through later pregnancy had babies with birth weights that were lower (but still healthy) than those in a control group.

Research at the Liggins Institute and elsewhere has shown that the intrauterine environment is an important factor in determining childhood growth and an individual’s later-life health. Recent studies have suggested that high birth weight babies have an increased risk of becoming obese as they grow up (with the consequent possibility of developing diabetes and other metabolic diseases).

Associate Professor Paul Hofman, who led this study, says that this modest reduction in birth weight may lead to a long-term decrease in the risk for obesity in offspring of the women who exercised during pregnancy.

The team also found lower cord blood levels of growth related peptides in offspring from the exercise group, suggesting that regular exercise may have affected the hormonal regulation of fetal growth.

In non-pregnant individuals, exercise is associated with an increased sensitivity to insulin, the hormone that regulates glucose metabolism. During pregnancy women normally develop a degree of ‘insulin resistance’ which is thought to be a necessary adaptation in order to maintain a regular supply of nutrients to the fetus. This study showed that while the exercise programme reduced birth weight, maternal glucose metabolism, and thus the nutrient supply to the fetus, was not affected.

This study is the first of its kind to demonstrate the potential long-term benefits of moderate exercise during pregnancy. However Hofman cautions that the reduced birth weight and levels of growth factors may be associated with potentially negative long-term consequences and emphasises the need to monitor these children closely as they grow up.

The research was published on line ahead of print in Journal of Endocrinology and Metabolism, May 2010, 95(5).
Exercise Training in Pregnancy Reduces Offspring Size without Changes in Maternal Insulin Sensitivity
Sarah A Hopkins, James C Baldi, Wayne S Cutfield, Lesley McCowan and Paul L Hofman.