Hospital readmissions and blood pressure management in the early postpartum period following hypertensive disorders of pregnancy.

BACKGROUND: Hypertensive disorders of pregnancy (HDP) affect 8-10% of pregnancies. They are an important cause of maternal morbidity, with crucial implications for long-term cardiovascular health. Whilst antenatal blood pressure (BP) management is well described and evidence-based, postnatal treatment thresholds are higher, management varies, and supporting evidence is limited. OBJECTIVES: To characterise postnatal BP trajectories in women with HDP and assess the prevalence of severe hypertension and emergency hospital presentation. STUDY DESIGN AND MAIN OUTCOME MEASURES: A retrospective cohort study used routinely collected NHS data from three maternity sites from women exposed to antihypertensive medication either during pregnancy, or within six weeks postpartum. 15,884 BP readings from 570 women were analysed between May and November 2024. Mixed regression models assessed blood pressure trajectories across the treatment groups. RESULTS: Severe postnatal hypertension (≥160/110 mmHg) occurred in 39% of women. 29% required ≥1 readmission to maternity triage. Antihypertensives prescribing at discharge was highly variable, with 28 regimens used; 38% of women were discharged without antihypertensive medication. BP peaked five days postpartum, whereas the median discharge occurred on day three. Amlodipine was associated with lower odds of re-admission compared with no treatment (OR 0.58 [95% CI 0.35-0.94]) and labetalol (0.54 [0.50-0.58]), and with a faster early BP decline (p < 0.001). CONCLUSION: Postnatal hypertension following HDP is common and remains a major driver of re-attendance. Differences in BP profiles by discharge medication suggest that antihypertensive choice influences early postnatal outcomes. Prospective studies and trials are needed to inform prescribing practices and to reduce morbidity.