(184) Risk factors for postpartum refractory hypertension and consequent pregnancy outcomes

To identify risk factors for refractory postpartum hypertension (RPHTN) in women with gestational hypertension (GH) and preeclampsia (PE), and to report outcomes of subsequent pregnancies.

Study Design: A retrospective cohort study of singleton pregnancies diagnosed with GH or PE between 2006-2022, at a single tertiary care center. We compared pregnancy outcomes between RPHTN patients (requiring >1 antihypertensive treatment) and those with an adequate response. The primary outcome was the rate of severe preeclampsia in subsequent pregnancies. The secondary outcomes included subsequent pregnancy cesarean delivery (CD) rate, gestational age at delivery, and birthweight. Chi-square or fisher exact test were used to analyzed categorical variables, and student’s t-test or Mann-Whiteny test were used for continuous variables. p< 0.05 was considered statistically significant.

Results: A total of 3,735 gravidas were included in our study, 3457 in the non-RPHTN group and 278 in the RPHTN group. Women with RPHTN were more likely to be older than 35 years (31.7% vs. 24.6%, p=0.009), had a lower rate of BMI > 30 (56.8% vs. 68.7%, p < 0.008), and a higher rate of severe preeclampsia (54.3% vs. 12.4%, p< 0.001) compared with women with non RPHTN. At the subsequent pregnancy the rate of severe preeclampsia, and cesarean delivery were higher in the RPHTN group (12.2% vs. 4.3%, p< 0.001; 66.1% vs. 36.1%, p< 0.001, respectively) compared with the non RPHTN group. Birth weight was lower in the RPHTN group (3,028+682 vs. 3,216+592 grams, p< 0.001) compared with the non RPHTN group.

Conclusion: RPHTN is associated with advanced maternal age, severe preeclampsia, and low BMI. Subsequent pregnancies in RPHTN patients are linked to higher rates of severe preeclampsia, CD, and low birthweights. Vigilant monitoring in subsequent pregnancies is recommended