(242) Stage 1 hypertension before 20 weeks of gestation is associated with postpartum anti-hypertensive use

Objective: Stage 1 hypertension (HTN), as defined by the American Heart Association, is associated with an increased risk of hypertensive disorders of pregnancy (HDP). Our objective was to evaluate if stage 1 HTN before 20 weeks of gestation was associated with persistent anti-hypertensive medication use at 6 weeks postpartum (PP).

Study Design: This was a retrospective cohort study at a single tertiary care center of all patients who delivered singleton gestations after 20 weeks of gestation between 2014-2016. Patients with chronic HTN and those who did not have 6 week PP data were excluded. Stage 1 HTN was defined as a maximum blood pressure (BP) of 130-139/80-89 before 20 weeks of gestation. Normotensive patients were those with all BPs < 130/80 before 20 weeks of gestation. The primary outcome was anti-hypertensive medication use at the 6 week PP visit, and the secondary outcome was PP re-admission for HDP. Multivariable logistic regression was used to adjust for potential confounders.

Results: 1546 normotensive patients were compared to 465 patients with stage 1 HTN before 20 weeks of gestation. Patients with stage 1 HTN were more likely to develop a HDP. Compared to normotensive patients, those with stage 1 HTN were significantly more likely to require anti-hypertensive medication at 6 weeks PP (8.8% vs. 2.9%, aOR 2.23; 95% CI, 1.41-3.54), even when the analysis was restricted to patients who developed a HDP (P=0.02). Patients with stage 1 HTN were also significantly more likely to be re-admitted for a HDP (3.9% vs. 1.5%, aOR 2.11; 95% CI, 1.10-4.06).

Conclusion: Stage 1 hypertension before 20 weeks gestation should be considered a risk factor for persistent anti-hypertensive use at 6 weeks PP and re-admission for HTN, and targeted for future study.