Prevalence and correlates of objectively measured physical activity and sedentary behavior among US pregnant women

Objective. Physical activity is recommended for pregnant women without medical or obstetric complications. This study described the prevalence and correlates of objectively-measured physical activity and sedentary behavior among United States pregnant women. Methods. Using cross-sectional data collected front the 2003 to 2006 National Health and Nutrition Examination Survey (NHANES). 359 pregnant women >= 16 years wore an accelerometer for 1 week. Results. Women participated in a mean of 12.0 minutes/day (standard error (SE) 0.86) of moderate activity and 0.3 minutes/day (SE 0.08) of vigorous activity. Mean moderate to vigorous physical activity varied by trimester: 11.5 minutes/day in first trimester, 14.3 minutes/day in second trimester, and 7.6 minutes/day in third trimester. On average, women spent 57.1% of their monitored time in sedentary behaviors. In multivariable adjusted models, moderate to vigorous physical activity was higher in the first (p = 0.02) and second (p < 0.001) trimesters compared to the third trimester. and among women with higher household income (p = 0.03) compared to lower household income. In multivariable adjusted models, average counts/minute was higher in the second compared to the third trimester (p = 0.04). Conclusion. Most pregnant women spent more than half of the monitored day in sedentary behaviors and did not meet recommendations for physical activity. (C) 2011 Elsevier Inc. All rights reserved.