Association of physical activity level during pregnancy with preterm birth and infant adiposity: longitudinal analysis from the MAASTHI cohort, India.

Background: Physical activity during pregnancy is thought to influence birth outcomes, but its association with it is not fully understood. We aimed to examine the association of sedentary behavior during pregnancy with preterm birth and infant adiposity measured at birth, 14 weeks, and one year of age.

Methods: In this cohort study, physical activity during pregnancy was assessed using the physical activity questionnaire. Gestational age at birth was determined soon after delivery and the infants were followed up until one year of age. Infant anthropometric measurements such as weight, length, crown-rump length, mid-upper arm circumference, waist and hip circumference, and skinfold thickness were assessed at each follow-up visit. Multivariable linear and logistic regression models were used to assess the association of sedentary behavior during pregnancy with preterm birth and infant adiposity, after adjusting for confounders.

Results: Among the 1315 pregnant women who participated in the study, 7.1% had sedentary behavior. Sedentary behavior during pregnancy was significantly associated with a higher incidence of preterm birth (OR = 1.43, p = 0.041). Sedentary behavior during pregnancy showed a significant association with adiposity in children as measured through hip circumference (OR = 2.53, p = 0.007) at the 14-week follow-up and the sum of skinfold thickness (OR = 1.53, p = 0.024) at one-year follow-up.

Conclusion: This study highlights a significant association between sedentary behavior during pregnancy and preterm birth, markers of adiposity in children from birth to one year of age. These findings underscore the importance of maintaining moderate physical activity during pregnancy.