Physical activity, uteroplacental and umbilical circulation, and the risk of gestational hypertension/preeclampsia

Despite extensive research, etiology of hypertensive disorders during pregnancy and the roles of promising preventive factors remain unknown. The goal of this work was to investigate the association of physical activity and uterine and umbilical artery blood flow, thus making inference about maternal-fetal circulation and placental resistance. The work also investigated the association between physical activity before and during early pregnancy and the development of gestational hypertension and preeclampsia.;Data were collected through the third phase of the Pregnancy, Infection, and Nutrition Study. Information on exercise before pregnancy was collected through a self-administered questionnaire at 24-29 weeks' gestation. Self-reported physical activity was obtained through a telephone interview at 17-22 weeks' gestation. Uterine and umbilical artery Doppler flow velocimetry waveforms were recorded through ultrasound examinations at 15-20 weeks' and 24-29 weeks' gestation. Diagnoses of gestational hypertension and preeclampsia were made through information collected at prenatal care visits.;Our findings indicate that physical activity during pregnancy does not appear to be associated with meaningful changes of resistance in uterine and umbilical arteries that would be related to maternal-fetal haemodynamics and blood volume delivery. Thus, physical activity during pregnancy was not associated with major alterations of maternal-fetal circulation.;Exercise before pregnancy through the 2nd trimester was associated with a slightly reduced risk of gestational hypertension. A reduced risk of gestational hypertension was also found among women reporting total moderate to vigorous physical activity and recreational activity in the highest category during pregnancy, but no association was found with work activity.;Exercise before pregnancy through the 2nd trimester was associated with an increased risk of preeclampsia. Total, work, and recreational activity during pregnancy generally had no association with the risk of preeclampsia.;In conclusion, this study generally provides evidence that self-reported physical activity was not associated with maternal-fetal circulation and few associations were identified for the development of hypertensive disorders. These findings support the public health and American College of Obstetric and Gynecology physical activity guidelines for pregnant women.