Physical activity during pregnancy and offspring cardiovascular risk factors: findings from a prospective cohort study

Objectives: The long-term consequences of maternal physical activity during pregnancy for offspring cardiovascular health are unknown. We examined the association of maternal self-reported physical activity in pregnancy (18 weeks gestation) with offspring cardiovascular risk factors at age 15. Design: Prospective cohort study. Setting: The Avon Longitudinal Study of Parents and Children (ALSPAC). Participants: 4665 maternal-offspring pairs (based on a sample with multiple imputation to deal with missing data) from the ALSPAC, a prospective cohort based in the South West of England with mothers recruited in pregnancy in 1991-1992. Primary and secondary outcome measures: Offspring cardiovascular risk factors at age 15; body mass index (BMI), waist circumference, systolic blood pressure, diastolic blood pressure, glucose, insulin, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and triglycerides. Results: Greater maternal physical activity was associated with lower BMI, waist circumference, glucose and insulin in unadjusted analyses. The magnitude of associations was generally small with wide Cls, and most associations attenuated towards the null after adjusting for confounders. The strongest evidence of association after adjustment for confounders was for glucose, although the 95% Cl for this association includes the null; a one SD greater physical activity during pregnancy was associated with a -0.013 mmol/L difference in offspring glucose levels (equivalent to approximately one-third of a SD; 95% Cl -0.027 to 0.001 mmol/L). Conclusions: Our results suggest that maternal physical activity in pregnancy, measured at 18 weeks gestation, is unlikely to be an important determinant of later offspring cardiovascular health. There was some suggestion of association with offspring glucose, but given that all other associations (including insulin) were null after adjustment for confounders, this result should be interpreted with caution.