Early pregnancy health behaviors, adverse pregnancy outcomes, and maternal blood pressure after pregnancy

Background: Individual health behaviors are associated with pregnancy outcomes, but their joint effects are rarely considered and their associations with health beyond pregnancy are uncertain. We aimed to examine associations between combinations of first trimester health behaviors with adverse pregnancy outcomes (APOs) and blood pressure 2-7 years after delivery, and to estimate the proportion of associations with later blood pressure that were mediated by APOs. Methods: Participants in the nuMoM2b and follow-up Heart Health Study prospective cohort were included. Physical activity, diet, sleep duration, and smoking were scored using the Life's Essential 8 framework. APOs were prospectively abstracted from medical records and included hypertensive disorders of pregnancy, preterm birth, gestational diabetes, small-for-gestational-age birth, or stillbirth. Latent profiles of health behaviors were constructed with structural equation modelling. Models were built using first trimester cardiovascular health scores on a scale of 0-100 for each of the four health behaviors. Risk of APOs and incident hypertension, and differences in continuous blood pressure 2-7 years after delivery based on behavioral profiles were assessed with Poisson or linear regression. Mediation analysis examined the proportion of associations between behavioral profiles and blood pressure mediated by APOs. Results: Among 8,700 nulliparas, four behavioral profiles were identified: Healthiest Behaviors (36%), Healthy Activity/Sleep with Poor Diet/Smoking (21%), Healthy Sleep Only (32%), and Least Healthy Behaviors (11%). Forty-nine percent (4,497) returned for blood pressure assessment 2-7 years after delivery. Adjusted risk of APOs was 12-23% higher across the less healthy behavioral profiles compared to the Healthiest Behaviors profile. Further, adjusted systolic and diastolic blood pressures were 0.86 and 1.04 mmHg higher, respectively, 2-7 years after delivery in those with less healthy behavioral patterns compared to the Healthiest Behaviors profile. Eleven percent of the association between behavioral profiles and diastolic blood pressure was mediated by APOs. Rates of incident hypertension were not significantly different across behavioral profiles. Conclusions: Less healthy combined health behavior profiles in early pregnancy were associated with APOs and higher blood pressure 2-7 years after delivery. The observed associations with later blood pressure were predominately direct effects, with limited mediation through APOs.