(265) Early Pregnancy Blood Pressure Trajectories Predict Preeclampsia and Gestational Hypertension Among Low Risk Pregnancies

Thursday, February 9, 2023

10:30 AM – 12:00 PM

Objective: Develop and validate a prediction model for risk of preeclampsia (PE) and gestational hypertension (GH) using early pregnancy blood pressure (BP) patterns plus risk factors (RF) routinely available in clinical settings among low and moderate risk pregnancies.

Study Design: Retrospective cohort of 249,892 low or moderate risk singleton pregnancies delivered at Kaiser Permanente Northern California hospitals in 2009-2019. Electronic health records excluded prior hypertension, heart, kidney or liver disease and history of PE. All BPs were < 140/90 at < 20 weeks gestation. Data were randomly divided into a training dataset (N=174,925;70%) for model development and a validation dataset (n=74,967;30%). We used group-based trajectory modeling of longitudinal clinical systolic BPs to identify early pregnancy BP trajectory (BPT) groups < 20 weeks. We fit multinomial logistic regression models to predict early PE (< 34 weeks), late PE (≥34 weeks) and GH including BPT alone or with multiple RF (BMI, parity, age, race/ethnicity, diabetes) vs. an initial BP alone or with other RF. C-statistics generated from the validation dataset evaluated model predictive performance.

Results: The sample of 249,892 low to moderate risk individuals had mean (SD) maternal age of 30.9 y (5.3), BMI of 26.0 kg/m² (5.8), 57% were nulliparous, and 63% were from Black, Hispanic, or Asian groups, and 100% had all normal BPs < 20 weeks. Overall, 992 (0.4%) developed early PE, 10,612 (4.3%) late PE, and 10,854 (4.3%) GH. BPT group models performed much better (C-statistic:0.664-0.732) than models with initial BP only (0.630-0.700), multiple RF alone, or in combination (Table 1). The best model performance (0.729-0.768) to predict early PE, late PE and GH included BPT groups plus BMI, parity, age, race/ethnicity, and diabetes.

Conclusion: Six BP patterns plus RF available in routine clinical care improved prediction of early and late PE, and GH in lower risk pregnancies. Our findings show promise to guide surveillance and strategies to distinguish risk among ostensibly low risk groups.

Primary Author(s)

EG
Erica Gunderson, PhD
Senior Research Scientist
Kaiser Permanente Northern California
Oakland, California, United States

Presenting Author(s)

Mara Greenberg, MD (she/her/hers)
Clinical and Research Director, Regional Perinatal Service Center
Kaiser Permanente Northern California
Berkeley, California, United States

Coauthor(s)

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Baiyang Sun, MPH
Kaiser Permanente Northern California Division of Research
Oakland, California, United States
MN
Mai Nguyen-Huynh, MD
Kaiser Permanente Northern California
Oakland, California, United States
JR
James Roberts, MD
Magee-Womens Research Institute
Pittsburgh, Pennsylvania, United States
SA
Stacey Alexeeff, PhD
Research Scientist
Kaiser Permanente Northern California
Oakland, California, United States