Activity restriction and risk of adverse pregnancy outcomes

SMFM recommends against activity restriction (AR) during pregnancy for any indication, however, AR is still commonly recommended. Outside of pregnancy, physical activity is protective against the development of hypertension (HTN) and cardiovascular disease but there are scant data on the associations of AR with hypertensive disorders of pregnancy and other adverse pregnancy outcomes (APOs). Secondary analysis of the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be (nuMoM2b) prospective cohort. Nulliparous singletons were followed at 8 sites from September 2010 - September 2013. Demographic and clinical data were collected at 4 timepoints, and participants were surveyed about AR recommendations at 22w0d-29w6d and delivery. We excluded patients with missing data on AR and age. Patients were grouped according to history of AR, and outcomes included: gestational HTN, preeclampsia, preterm delivery, and small for gestational age (SGA) neonate. Associations between AR and outcomes were examined using uni- and multivariable logistic regression model adjusting for APO risk factors to account for potential confounders. Of 10,038 participants, 9,312 met inclusion criteria and 1,386 (14.9%) were recommended AR. 3,197 (34%) had an APO [719 (52%) in the AR group and 2,492 (31%) in the no AR group]. The AR group had higher proportions of White race, obesity, chronic hypertension, renal disease, and short cervix. After adjustment for baseline differences in demographics and medical comorbidities, the AR group had significantly increased odds of gestational HTN [OR 1.61 (95% CI 1.35-1.93)], preeclampsia/eclampsia [OR 2.52 (95% CI 2.05-3.08)] and preterm birth [OR 3.18 (95% CI 2.58-3.92)], but not delivery of an SGA neonate. These findings were unchanged after adjusting for short cervix (Table). AR in pregnancy was associated with increased odds of hypertensive disorders of pregnancy and preterm birth but not SGA after adjustment for risk factors, but the direction of association needs further investigation. AR should not be recommended for any obstetric indication.