Newswise — Fewer than 1 in 4 pregnant women meet physical activity guidelines set by doctors and health officials, according to a University of North Carolina at Chapel Hill study.

Guidelines set by the American Congress of Obstetricians and Gynecologists in 2002 recommend pregnant women get 30 minutes or more of moderate exercise daily, or on most days, if they have no medical or obstetric complications. Similar guidelines issued by the Department of Health and Human Services in 2008 suggest pregnant women get at least 150 minutes of moderate intensity aerobic activity per week.

“Physical activity during pregnancy has a number of health benefits,” said Kelly Evenson, Ph.D., research associate professor of epidemiology in the UNC Gillings School of Global Public Health and author of the new study. “It may help prevent gestational diabetes, support healthy gestational weight gain and improve mental health.”

According to the study, women in their first trimester were more likely to meet the physical activity recommendations than those in more advanced stages of their pregnancy, Evenson said. Women with health insurance and non-Hispanic whites were more likely to meet the guidelines than others. Walking was the most common leisure time physical activity reported.

The findings were published in the March 2010 issue of the journal Preventive Medicine.

Evenson said the study would help health-care providers and policymakers better understand which women are getting the exercise they need during pregnancy, and what method of physical activity they are most likely to choose.

“These data could be used to set national objectives, such as with the Department of Health and Human Services’ ‘Healthy People’ initiative,” she said. “By having this data, we can monitor trends over time to determine if more women are getting exercise throughout their pregnancy.”

“Healthy People” involves professionals, policymakers, researchers and the general public in putting together national health objectives to increase the quality and years of healthy life, and eliminate health disparities among people of all ages.

For the study, Evenson and Fang Wen, a programmer in the public health school’s epidemiology department, used data from the National Health and Nutrition Examination Survey collected between 1999 and 2006. The data included interviews with 1,280 pregnant women aged 16 or older. The questionnaire defined moderate intensity activities as tasks that caused light sweating or a slight to moderate increase in breathing or heart rate, and vigorous intensity as activities that caused heavy sweating or large increases in breathing or heart rate.

The proportion of women who were active enough to meet the guidelines’ recommendations was about 23 percent.

The national survey also showed 23 percent of women reported getting some activity going to and from work or school; 54 percent got moderate to vigorous household activity; and 57 percent reported moderate to vigorous leisure activity within a month before the interview. Moderate to vigorous leisure time activity was significantly greater among women in the first trimester compared to third trimester.

For more information on the National Health and Nutrition Examination Survey, visit http://www.cdc.gov/nchs/nhanes.htm.