The Grapevine

Walking May Help Women With High BMI, History Of Pregnancy Loss

Walking could help improve chances of pregnancy for women with a history of pregnancy loss, according to researchers from the University of Massachusetts Amherst. 

A study titled "A prospective study of physical activity and fecundability in women with a history of pregnancy loss" was published in the journal Human Reproduction on April 10.

Fecundability refers to the probability of being pregnant in a single menstrual cycle. For the study, the researchers wanted to explore how physical activity could impact fecundability as previous research suggested it can alter endocrine function.

"We were happy to be able to add scientific evidence to general recommendations about physical activity. This is especially true for the results about walking for even limited blocks of time. Walking has great potential as a lifestyle change because of its low cost and availability," said Brian Whitcomb, associate professor of biostatistics and epidemiology in the School of Public Health and Health Sciences.

Recent graduate Lindsey Russo conducted the study along with Whitcomb, who was her advisor. From four medical centers in the U.S., they recruited a total of 1,214 healthy women. The participants were aged between 18 to 40 years and experienced one or two prior pregnancy losses.

The participants were tracked for up to six menstrual cycles during their attempts to conceive. Those who were successful were followed through pregnancy. Tracking involved collection of urine samples, the use of a fertility monitor, and assessment of physical activity with the help of the International Physical Activity Questionnaire (IPAQ-SF).

After completion and analysis, the authors reported that fecundability varied significantly by body mass index. Women who were overweight or obese saw improved chances of pregnancy associated with walking at least 10 minutes at a time. 

"One of our main findings is that there was no overall relationship between most types of physical activity and the likelihood of becoming pregnant for women who had already had one or two pregnancy losses, except for walking, which was associated with higher likelihood of becoming pregnant among women who were overweight or obese," explained Russo.

Moderate levels of activity, sedentary behavior and other such categories were not associated with fecundability in the overall analysis or when classified by BMI. Regarding limitations of the research, the authors stated that the participants chosen may not be representative of the general population.

The relationship cannot be established as causal yet since physical activity is related to other behaviors and lifestyle factors. Exercise habits may also differ in women with a history of miscarriage compared to those without, they added.

The researchers concluded that the study supported positive evidence for the benefits of physical activity in women who are attempting to conceive, adding that women with a higher BMI could especially benefit from walking. They also expressed interest in further study to understand the underlying mechanisms of how walking and vigorous activity could affect fecundability.