(1161) Association between physical activity level and chronic inflammatory and vascular pathology in the placenta

Chronic placental inflammation (CI) and maternal vascular malperfusion (MVM) are associated with adverse pregnancy outcomes. While regular physical activity is recommended in pregnancy, the association between activity level and placental histology is unknown, and may reflect underlying effects of activity level on pregnancy. The objective of this study is to characterize the association between activity level and placental CI and MVM in obese and non-obese patients.

Study Design:

This is a secondary analysis of a subset of a clinical trial comparing group vs individual prenatal care on pregnancy outcomes for 2,146 patients. Patients with complete placental histology and International Physical Activity Questionnaire (IPAQ) were included. Birth outcomes and demographics were obtained from chart review and patient surveys.  Patients were categorized into high activity vs low or moderate activity. BMI at first prenatal visit was categorized as obese (BMI ≥30) or non-obese (BMI < 30).  Log binomial models were used to assess the association between activity level and placental histology among obese and non-obese women.

Results:

299 patients met inclusion criteria. 40.4% of low/moderate activity group were obese and 38.3% of the high activity group were obese (Table 1). 44.5% of placentas had CI and 45.8% had MVM.  Among obese patients (n= 119), high physical activity was not associated with CI or MVM (Table 2).  Contrastingly, among non-obese women, high activity trended towards an increased risk of CI (aRR 1.35, 95% CI 0.96, 1.90) and was associated with increased risk of MVM (aRR 1.48, 95% CI 1.07, 2.06, p = 0.02).

Conclusion:

High activity was not associated with CI or MVM among obese women, but among non obese women was unexpectedly associated with increased MVM and trended with an increased risk of CI. Future research should further examine activity level and pregnancy physiology including placental analysis.