(674) Mean arterial pressure as an early predictor of preeclampsia: A retrospective cohort study

Objective: To estimate the utility of early pregnancy mean arterial pressure (MAP) for predicting later preeclampsia diagnosis, and to compare the predictive ability of MAP with that of the risk categories recommended by the United States Preventive Services Task Force (USPSTF).

Study Design: A retrospective cohort study of all pregnant patients with a first prenatal visit by 16 weeks’ gestation and delivered in our system from 1/2021 – 12/2022. MAP was calculated using data captured at the initial visit. Patients’ preeclampsia risk was assigned based on 2021 USPSTF guidance, in which elevated risk was defined as having 1 high risk or 2 or more moderate risk factors for the condition and low risk was defined as having none. The primary outcome was diagnosis of preeclampsia. The predictive abilities of MAP and the USPSTF risk categories were estimated using area under the receiver operating characteristic curves (AUROC). The Youden index was used to identify an optimal MAP cut-point, and the predictive characteristics of this value were compared to those associated with an elevated USPSTF risk category.

Results: Of 1325 patients, 146 (11.0%) developed preeclampsia. MAP outperformed the USPSTF risk categories with respect to predicting this diagnosis, as evidenced by an AUROC of 0.73 compared to 0.64 (Χ² = 2.70, p = 0.10). The optimal MAP cut-point for predicting preeclampsia was 88.5 mm Hg. Contrasted with an elevated USPSTF risk category, MAP predicted preeclampsia with improved sensitivity (74.7 vs 61.6%), comparable specificity (62.3 vs 66.6%), and improved positive and negative predictive values (19.7 vs 18.6%; 95.2 vs 93.3%). MAP was similarly predictive of preeclampsia regardless of a patient’s determined risk for the condition.


Conclusion: Early pregnancy MAP is a modest predictor of preeclampsia and has improved characteristics as a screening test relative to application of the USPSTF risk categories. Particularly among low-risk patients – who might not otherwise be prescribed aspirin for preeclampsia prophylaxis – early pregnancy MAP may be considered as an adjunct for preeclampsia risk stratification.