(541) Preconception and First Trimester Blood Pressure: Risks of Hypertensive Disorders in Pregnancy Using AHA Guidelines

This retrospective study utilized the Clalit Health Services database,and included all singleton pregnancies from 2010 to 2023 with at least one BP measurement within one year before conception until 13 weeks of gestation. Participants were classified into three groups according to the AHA guidelines:normotensive, elevated BP (systolic BP [SBP] of 120-129 mm Hg with diastolic BP [DBP] < 80 mm Hg), and stage 1 hypertension (SBP of 130-139 mm Hg or DBP of 80-89 mm Hg). Patients with chronic hypertension were excluded. Maternal, neonatal, and composite hypertensive outcomes were compared between the groups. Subgroup analyses were conducted for patients with obesity (BMI ≥ 30) and those with pre-gestational diabetes mellitus (PGDM). A logistic regression model adjusted for maternal age, aspirin use, BMI, and PGDM was utilized.

Results:

The study included 57,524 women. Of these, 46,924 (81.6%) were normotensive, 6,636 (11.5%) had elevated BP, and 3,964 (6.9%) had stage 1 hypertension. The incidence of composite hypertensive adverse outcome increased in a dose-response manner: 2.8% in the normotensive group, 6.4% in the elevated BP group, and 8.2% in the stage 1 hypertension group (p < 0.001). Neonatal NICU admissions were more common in the elevated BP and stage 1 hypertension groups compared to the normotensive group (p < 0.001). Logistic regression revealed that elevated BP, stage 1 hypertension, maternal age ≥35 years, and PGDM were independently associated with increased odds of composite hypertensive outcome: OR 2.22 (95% CI 1.94-2.55), OR 2.75 (95% CI 2.34-3.24), OR 1.88 (95% CI 1.57-2.27), and OR 1.55 (95% CI 1.29-1.86), respectively (p < 0.001 for all).

Conclusion:

Preconceptional and first-trimester elevated BP and stage 1 hypertension, as defined by the AHA guidelines, are associated with an increased risk of maternal HDP.