Exercise During Pregnancy: Good for Babies' Hearts

It's long been known that exercising while pregnant is great for expectant moms. But a new study out of Kansas City, Mo., has found that working out also has a positive effect on these moms' unborn babies.

The study, titled Effects of Maternal Exercise on the Fetal Heart, found that fetuses whose mothers exercised while pregnant had significantly lower heart rates than fetuses whose mothers did not exercise. The study also found that unborn babies exposed to exercise had higher heart-rate variability. Heart rate variability, or HRV, measures beat-to-beat changes in heart rate. Higher HRV measures are thought to be associated with better heart health.

Dr. Linda May, a researcher on the study, said the research definitely suggests that exercise can have a positive effect on people even before they are born.

"This study suggests that a mother who exercises may not only be imparting health benefits to her own heart, but to her developing baby's heart as well," said May, a member of the department of anatomy at Kansas City University of Medicine and Biosciences (KCUMB), in a press release. "As a result of this pilot study, we plan to continue the study to include more pregnant women."

The study included 10 babies from about 24 weeks gestation to full-term. Measures such as breathing and body movements were recorded using magnetocardiography (MCG), which is the magnetic equivalent of an electrocardiogram (ECG). MCG is considered a safe method of measuring electrical currents created by the fetal cardiac and nervous systems. The group of researchers measured the unborn babies' movements about once every four weeks. Researchers found that the difference in fetuses' long- and short-term HRV was "statistically significant" between the exercising and non-exercising groups at 32 weeks. A difference was still seen at 36 weeks, but this difference was not statistically significant.

The 10 women that participated in the study were categorized according to how long they exercised, how intensely they exercised, and how often they participated in physical activity.

May will present the findings of this study at the 121^st meeting of the American Physiological Society. According to the association's website, APS is a non-profit association dedicated to the study of physiology, a science that examines how cells, tissues, organs and molecules affect health. Most of APS' 10,500 members are health professionals of some sort. The association was founded in 1887 and has its headquarters in Bethesda, Maryland.

Newswise Medical News. "Exercise During Pregnancy Leads to a Healthier Heart in Moms- and Babies-To-Be." Available at: http://www.newswise.com/articles/view/538985/?sc=mwhn

"Heart Rate Variability." Available at: http://www.macses.ucsf.edu/Research/Allostatic/notebook/heart.rate.html

The American Physiological Society. "About APS." http://www.the-aps.org/about/index.htm