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Poster Session II Thursday, February 14 • 4:00 PM - 5:30 PM • Octavius Ballroom • Caesars Palace| Volume 220, ISSUE 1, SUPPLEMENT , S288-S289, January 01, 2019

425: Early pregnancy blood pressure trajectory and risk of preeclampsia

      Objective

      Recently updated ACC/AHA guidelines redefine blood pressure (BP) categories as Stage 1 hypertension (systolic 130-139mmHg or diastolic 80-89mmHg), Elevated (systolic 120-129mmHg and diastolic <80mm) and Normal (<120/<80 mmHg), but their relevance to an obstetric population is uncertain. We sought to evaluate preeclampsia risk based on early pregnancy BP category and trajectory.

      Study Design

      This is a secondary analysis from a prospective observational study of nulliparous women with singleton pregnancies conducted at eight clinical sites between 2010-2014 (nuMoM2b cohort). Women included in this analysis had no history of pre-pregnancy hypertension (HTN) or diabetes. We compared the frequency of preeclampsia and gestational HTN among women based on BP category at first study visit (Normal, Elevated, or Stage 1 HTN) and systolic BP trajectory between two study visits. BP trajectories were categorized based on systolic BP difference between visit 1 and 2 as stable (<5mmHg difference), upward (≥5mmHg) or downward (≤-5mmHg) and by change in category between visits. Associations of BP category and trajectory with preeclampsia risk were assessed via univariate analysis and multinomial logistic regression analysis including co-variates identified in a backward stepwise approach.

      Results

      8,924 women were included in the analysis. Study visit 1 occurred at mean gestational age (GA) 12.1 ± 1.5 weeks and study visit 2 at mean GA 19.0 ± 1.6 weeks. First trimester BP category was significantly associated with subsequent preeclampsia and gestational HTN, with increasing BP category associated with a higher risk. Stage 1 HTN at baseline was associated with an increased risk for all categories of pregnancy-associated HTN; increased in a stepwise fashion over Elevated BP at baseline (see table). Systolic BP trajectory was significantly associated with preeclampsia risk (p<0.001) as was change in BP category between visits (p<0.001). Compared with a stable systolic trajectory, an upward trajectory was associated with an aOR 1.77 (95%CI 1.45-2.17) of preeclampsia after adjustment for maternal age, race, body mass index and first trimester BP (see figure).

      Conclusion

      In nulliparous women, BP category and systolic trajectory in early pregnancy are independently associated with preeclampsia risk. These findings may aid in identification of women who might benefit from risk- reducing interventions in the late first and early second trimester, such as low-dose aspirin.
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