(Reuters) - Moderate exercise is encouraged during pregnancy for plenty of reasons, but it may also help women avoid gaining too much weight, say UK researchers.
They reviewed studies since the 1990s looking at whether exercise alone helps prevent excess weight gain during pregnancy, and found that it does, or helps with weight loss after delivery, and found that it doesn’t.
They also found a total of only five solid studies on those questions.
“There isn’t enough research being conducted regarding the effects of exercise on gestational weight gain or postpartum weight loss,” said Dr. Kirsty Elliot-Sale of the Sport, Health and Performance Enhancement Research Group at Nottingham Trent University, who led the review.
“Of those few good - as defined by appropriate research design - studies, exercise seems to be an effective tool during pregnancy to limit excessive gestational weight gain but so far exercise (walking) has not been shown to be effective for postpartum weight loss,” Elliot-Sale told Reuters Health by email.
The U.S. Institute of Medicine advises women who are normal weight before they get pregnant to gain 25 to 35 pounds during their pregnancy. Women who are overweight should gain from 15 to 25 pounds, and obese women should gain from 11 to 20 pounds, according to IOM guidelines.
Elliot-Sale said that weight gain exceeding the appropriate amount has implications for both mothers and infants. It also contributes to postpartum weight retention and ultimately, if unchecked, a higher risk of obesity.
Elliot-Sale added that it’s an area of research that urgently needs to be discussed and addressed.
“Women should be supported and guided during this potentially overwhelming time and losing pregnancy-related weight should be made easier and not overtake this special time,” she said.
Elliot-Sale and colleagues reviewed the results of three research studies that compared exercise programs to regular care, or to other types of interventions during pregnancy, and two studies done during the year following pregnancy.
The researchers found that, on average, women who exercised during their pregnancies gained about five pounds less than their counterparts who didn’t exercise.
There were no differences in weight loss after pregnancy between women who exercised and those who didn’t, according to the results in the British Journal of Sports Medicine.
Elliot-Sale said she still believes that exercise is the answer, which is why she’s now conducting studies on weight loss after pregnancy.
“Obviously, physical activity should be paired with good nutritional practices; however women should be cautioned not to overly restrict dietary energy intake whilst breastfeeding,” Elliot-Sale said.
“I love it and my niche happens to be women and heart disease and trying to get the OB/GYNs to take more of an active role in managing women’s comprehensive health,” said Dr. Mary Rosser.
“I think the more we see in the literature studies like this, the more awareness it raises, not only on the patients’ part, but I’m talking about the providers’ part as well,” said Rosser, an obstetrician/gynecologist at Montefiore Medical Center in New York.
Rosser, who was not involved in the review, said the fact that only five studies were available highlights the need for more research.
“I think that that’s just more evidence that we need more randomized control trials to look at this issue, and it just increases our awareness,” she said.
Rosser said that excessive weight gain during pregnancy and weight retention between pregnancies is becoming more common. She added that doctors are seeing more women who are overweight before ever getting pregnant.
Excessive weight gain could increase the risk of more complicated pregnancies, preeclampsia and gestational diabetes, she noted.
“We also have now seen in the literature that women who have these problems during pregnancy are at up to five times greater risk of having cardiovascular disease in their lifetime,” Rosser said.
Rosser said that women who exercise before pregnancy are more likely to work out during pregnancy, but it’s not too late to start an exercise program during pregnancy.
“We have to educate women that it’s okay to exercise during pregnancy,” she said.
Rosser advises women to talk to their obstetricians and ask about what kinds of activities are safe.
“I am a fan of brisk walking, and if you have no other complications I think that’s very helpful,” she said. “And also psychologically it helps everyone to exercise.”
SOURCE: bmj.co/1yXEL1I British Journal of Sports Medicine, online November 18, 2014.