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.

Source
University of North Carolina at Chapel Hill

The research team studied a group of 13,475 women from the Nurses’ Health Study II. During 10 years of follow-up, 860 incident GDM cases were identified. After adjustment for known risk factors for GDM including age, family history of diabetes, parity, physical activity, smoking status, sugar-sweetened beverage intake, alcohol intake, prepregnancy BMI, and Western dietary pattern, intake of sugar-sweetened cola was positively associated with the risk of GDM. No significant association was found for other sugar-sweetened beverages or diet beverages.

“Compared with women who consumed less than 1 serving per month, those who consumed more than 5 servings per week of sugar-sweetened cola had a 22% greater GDM risk,” notes Dr. Chen.

Gestational diabetes mellitus (GDM), defined as glucose intolerance beginning during pregnancy, is one of the most common pregnancy complications. Women with GDM are at increased risk for complications and illness during pregnancy and delivery, as well as post-pregnancy type 2 diabetes. Children of mothers with GDM are at increased risk for obesity, glucose intolerance, and early onset diabetes.

Although the underlying mechanism remains unclear, available evidence suggests that the main defect in the development of GDM is relatively diminished insulin secretion coupled with pregnancy-induced insulin resistance. The researchers discuss a number of explanations of their findings. Consuming a large amount of sugar-sweetened beverages could contribute to a high glycemic load (GL) by providing a large amount of rapidly absorbable sugars. High-GL foods induce a greater plasma glucose response after eating which can result in insulin resistance and impaired beta cell function. (Pancreatic beta cells make insulin.) In addition, higher sugar intake itself may lead to impaired pancreatic cell function.

“We don’t know why significant association was only found in sugar-sweetened cola, but not other types of sugar-sweetened beverages – fruit drinks, other soft drinks, etc.,” says Dr. Chen. “One of the explanations could be the tremendous popularity of cola in the US.”

Previous studies in children and adults have shown that regular consumption of sugary drinks is associated with excess caloric intake, greater weight gain, and increased risk of obesity. Sugary drinks have also been linked to type 2 diabetes and other metabolic disorders.

“This is the first study on the impact of sugar-sweetened beverages on GDM risk,” notes Dr. Chen. “This finding is important because sugar-sweetened beverages are the leading source of added sugars in the American diet, particularly in the age group most likely to conceive. Cutting down sugary drinks is clearly an important way to reduce this common pregnancy complication.”

According to the National Health and Nutrition Examination Survey 1999-2001, from 1977 to 2001, soft drink intake increased from 4.1% to 9.8% for 19- to 39-year-olds. In percentage terms, soft drink intake was highest among this age group in comparison to other ages.

This study was supported by the National Institutes of Health and part of the work was done when Dr. Chen received an Intramural Research Training Award Fellowship under Dr. Cuilin Zhang (senior author) at the Division of Epidemiology, Statistics, and Prevention Research at the NICHD.

Source:
Leslie Capo
Louisiana State University Health Sciences Center