A5082 Excessive Umbilical Cord Coiling Confers Risk of Elevated Nocturnal Blood Pressure and Severe/Early-Onset Preeclampsia

Abstract

Objectives: To investigate the associations between umbilical cord (UC) coiling, feto-placental vascular resistance and maternal blood pressure (BP) during pregnancy. Methods: We retrospectively analyzed 502 pregnant women suspected of hypertensive disorders in the third trimester from a hospital-based cohort, who underwent ambulatory blood pressure monitoring and umbilical artery Doppler velocimetry examinations within 14 days before delivery. Results: By applying quantile regression, a significant quantile-dependent positive association between UC coiling index and umbilical artery pulsatility index (UAPIMOM; converted to multiples of median) was observed from above 0.75th quantiles for each parameter. Using the cutoffs both at the 0.75th quantile to define high UC coiling ( ≥ 0.28 coils/cm) and high UAPIMOM ( ≥ 1.30), respectively, a graded increase in BP level was observed from patients with both low, either high and both high categories. Multivariate linear and quantile regression revealed that the high UC coiling/high UAPIMOM interaction was significantly correlated with nighttime mean diastolic BP level. Moreover, UC hypercoiling ( ≥ 0.3 coils/cm) was significantly correlated with nighttime diastolic BP with an average increase of ∼5 mmHg from the 0.05th to 0.70th quantiles and independently predicted the occurrence of severe (odds ratio 2.32, 95% CI: 1.22 to 4.41) and early-onset (odds ratio 2.43, 95% CI: 1.18 to 4.97) preeclampsia after adjusting for covariates. Further mediation analysis showed that elevated high UAPIMOM ( ≥ 1.30) could explain 12.2% of the UC hypercoiling → high nighttime DBP association. Conclusion: The present work identifies excessive UC coiling, and its interaction with increased feto-placental vascular resistance, as novel risk factors for nocturnal BP elevation and preeclampsia.