(849) Hypertensive Outcomes in Twin Pregnancies with Elevated Blood Pressure Defined by AHA 2017 classification

Twin pregnancies are associated with an increased risk of hypertensive disorders of pregnancy (HDP). In 2017, the American Heart Association (AHA) redefined elevated blood pressure (BP) as systolic BP (SBP) of 120–129 mmHg with diastolic BP (DBP) < 80 mmHg. However, data on the implications of elevated BP within this range among twin gestations remain limited. This study aimed to evaluate the association between elevated BP- measured preconceptionally or in the first trimester—and the risk of HDP in twin pregnancies.

Study Design:
This retrospective cohort study included all nulliparous women with twin pregnancies from 2010 to 2023 who had at least one BP measurement from one year before conception until 13 weeks of gestation. Chronic hypertension was an exclusion criterion. Patients were classified according to the AHA 2017 BP classification. Maternal and neonatal outcomes were compared between the normotensive and elevated BP groups. The composite HDP outcome included preeclampsia (with and without severe features), eclampsia and HELLP syndrome.  A multivariable logistic regression model adjusted for maternal age, aspirin use, BMI, PGDM and chorionicity was utilized.

Results:

A total of 1,070 patients were classified as normotensive and 50 as having elevated BP. Baseline characteristics were similar between groups. The elevated BP group had significantly higher rates of preeclampsia without severe features (22% vs. 9.8%, p=0.017) and  composite HDP (36% vs. 16.8%, p=0.002). In adjusted analysis, both elevated BP and PGDM were independently associated with increased odd of composite HDP outcome: aOR 2.89 (95% CI 1.57-5.31), aOR 1.96 (95% CI 1.17-3.28), respectively, p< 0.001 for both.

Conclusion:

Elevated BP in the preconception and first trimester period is associated with a nearly threefold increased risk of HDP in twin pregnancies.