FRIDAY, Nov. 21 (HealthDay News) -- Doing aquarobics during pregnancy reduces the amount of pain-killing medication requested by women during labor, according to a Brazilian study that included 71 expectant mothers.

Half the women were assigned to attend three 50-minute sessions a week of aquarobics during their pregnancy, while the other half acted as a control group.

"We found no statistically significant differences in the duration of labor or they type of delivery between the two groups," study author Rosa Pereira, of the University of Campinas in Sao Paulo, said in a news release. "However, only 27 percent of women in the aquarobics group requested analgesia, compared to 65 percent in the control group. This represents a 58 percent reduction in requests."

There's some debate about the wisdom of women exercising during pregnancy. The main concern is that exercise may interfere with fetal/placental demands and compromise fetal development or growth or increase the risk of abnormalities. Pereira and colleagues concluded that aquarobics had no harmful effect on the cardiovascular health of pregnant women and also confirmed the well-being of infants born to the mothers who did aquarobics.

"We've shown that the regular practice of moderate water aerobics during pregnancy is not detrimental to the health of the mother or the child. In fact, the reduction in analgesia requests suggests that it can get women into better psycho-physical condition," Pereira said.

The study was published in the journal Reproductive Health.

More information

The U.S. National Women's Health Information Center has more about labor and birth.