Does "Sitting" Stand Alone? A Brief Report Evaluating the Effects of Prenatal Sedentary Time on Maternal and Newborn Anthropometric Outcomes.

BACKGROUND: Research on sedentary behavior and effects on maternal and newborn outcomes has been inconclusive. The objective of this report was to correlate sedentary time with maternal and fetal anthropometric measurements and compare the effect on sedentary time based on meeting prenatal activity guidelines. METHODS: Healthy pregnant women (N = 61) in their second trimester (24-28 wk gestation) provided 7-day accelerometry data. Outcomes, including neonatal weight, length, and body fat percentage, were collected 24 to 48 hours after delivery. Placenta weight was measured immediately after delivery. Gestational weight gain was calculated by subtracting self-reported prepregnancy weight from measured weight at 38 weeks gestation. Correlations between sedentary time and outcomes were tested with Spearman and Pearson coefficient of correlations in all women separately and in accordance with the 2019 Canadian prenatal exercise guidelines. RESULTS: No significant associations were found between sedentary time and the selected outcomes, even when compared by prenatal exercise level. There was no difference in total time spent sedentary between active (576.7 [52.8] min) and inactive women (599.3 [51.6] min). CONCLUSIONS: Meeting exercise recommendations during pregnancy does not significantly decrease total sedentary time. Future studies should aim to evaluate the health effects of both decreasing sedentary time and meeting prenatal exercise guidelines.