According to the Malmo University Hospital in Sweden, the major concern with exercise during pregnancy was the correlation between hyperthermia in the mother, or elevated body temperature, and neural tube defects in her baby. Some research has disproved this notion, however. During a normal, healthy pregnancy, exercise, especially the aerobic kind, is beneficial.
Kansas City University of Medicine and Biosciences
A study completed in 2008 and led by Linda May of the Kansas City University of Medicine and Biosciences found that babies as well as mothers benefit from exercise during pregnancy. May and her colleagues studied 10 women and found that their fetuses exhibited much lower heart rates after their mothers exercised than those whose mothers did not. May concluded that maternal exercise is instrumental in the healthy development of a baby's heart.
Malmo University Hospital, Sweden
In 2005, researchers in Sweden determined that while maternal hyperthermia is associated with fetal neural tube defects, a mother's exercise does not necessarily cause hyperthermia if she is healthy. Forty pregnant women and 11 non-pregnant women participated in low-impact aerobics, with their core body temperatures recorded before, during and after the exercise session. Their temperatures did not dramatically increase during or after exercise. However, the women were pushed to only approximately 69-percent exertion, so the university's findings only rule out hyperthermia during exertion of up to 70 percent of a woman's maximum heart rate.
National Institute of Public Health, Denmark
After the Danish National Birth Cohort issued an opinion that maternal exercise contributes to preterm births, the National Institute of Public Health conducted a study of more than 87,000 women between 1996 and 2002. The results actually showed a 40-percent decrease in risk of premature birth. Only 4.9 percent of the exercising women, who engaged mostly in swimming, bicycling and low-impact aerobics, suffered preterm labor. NIPH's conclusion was that women who exercise during pregnancy are less likely than their non-exercising counterparts to go into labor early.
Physicians' Opinions
Despite compelling evidence that some exercise is beneficial to pregnant mothers and their babies, a study by Northern Arizona University revealed that only approximately half of the obstetricians surveyed recommended exercise to their patients. NAU polled 85 physicians who specialized in obstetrics and gynecology and two who specialized in other fields. Most reported that they were still reluctant to suggest exercise to pregnant women who did not regularly exercise before they conceived and advised against strenuous exercise even to women who exercised before becoming pregnant. Half of those doctors who did recommend exercise advised their patients to cut back in their third trimesters.
References
- "Journal of Sports Science and Medicine"; Recommendations Regarding Exercise During Pregnancy; Pauline L. Entin and Kelly M. Munhall; Sept. 2006
- American Physiological Society: Exercise During Pregnancy Leads to a Healthier Heart for Moms- and Babies-To-Be
- PubMed: Low-Impact Exercise During Pregnancy -- A Study of Safety
- "American Journal of Epidemiology"; Physical Exercise During Pregnancy and the Risk of Preterm Birth; Mette Juhl, et al.; Feb. 2008
