Management of Postpartum Hypertensive Disorders of Pregnancy

Abstract

Background. Hypertensive disorders of pregnancy (HDP) are increasingly common and have important implications for maternal health, healthcare utilization, and health disparities. There is limited evidence to support best management of postpartum individuals with HDP, including home blood pressure (BP) monitoring (HBPM) and choice of antihypertensive agents. For patients experiencing preeclampsia with severe features, there is robust evidence supporting delivery of the infant and treatment with magnesium sulfate (MgSO4). However, MgSO4 may cause unpleasant side effects and, less commonly, toxicity. Patients receiving MgSO4 require additional monitoring (e.g., urinary catheterization) and often have activity restrictions, which impact their postpartum experience. Evidence regarding the optimal (lowest effective) dose and (shortest effective) duration of MgSO4 treatment is needed. Methods. We searched Medline®, Cochrane, Embase®, CINAHL®, and ClinicalTrials.gov from inception to December 1, 2022. After double screening, we extracted study data and risk of bias assessments into the Systematic Review Data Repository Plus (SRDR+; https://srdrplus.ahrq.gov). We evaluated the strength of evidence (SoE) using standard methods. The protocol was registered in PROSPERO (registration number CRD42022313075). Results. We found 13 eligible studies (3 randomized controlled trials [RCTs], 2 nonrandomized comparative studies [NRCSs], 8 single-arm studies) evaluating postpartum HBPM, 17 RCTs evaluating pharmacological treatment of postpartum HDP, and 43 studies (41 RCTs and 2 NRCSs) that compared alternative MgSO4 regimens. HBPM programs probably increase submission of any BP measurements during recommended time intervals (moderate SoE) and may increase the number of BP measurements obtained overall (low SoE). Studies have not found that HBPM affects the rate of BP treatment initiation (low SoE), but HBPM may reduce unplanned hypertension-related hospital admissions (low SoE). Most patients were satisfied with management related to HBPM (low SoE), and HBPM probably compensates for racial disparities in office-based follow-up (moderate SoE). In patients with preeclampsia or gestational hypertension (HTN), oral furosemide may shorten the duration of postpartum hypertension (low SoE). There was insufficient evidence regarding the comparative benefits and harms of other antihypertensive medications. Compared with 24-hour treatments, shorter duration MgSO4 regimens shorten the urinary catheterization time (high SoE), time to ambulation (high SoE), and time to breastfeeding (moderate SoE); and may shorten time from delivery to contact with the infant and decrease toxicity as manifested by lost deep tendon reflexes (both low SoE). Loading dose only regimens increase the risk of a recurrent seizure in patients with eclampsia (moderate SoE). Lower dose MgSO4 regimens, compared to standard dose regimens, reduce early signs of magnesium toxicity (high SoE), may approximately double the risk of recurrent seizure in patients with eclampsia (low SoE), but may not affect 5-minute Apgar scores in infants of patients with preeclampsia with severe features (low SoE). There is insufficient evidence regarding potential harms of concomitant use of nifedipine or other antihypertensive medications. Conclusion. HBPM probably improves ascertainment of BP, allowing early recognition of hypertension in postpartum patients, and probably compensates for racial disparities in office based follow-up. The evidence suggests furosemide may shorten the duration of postpartum HTN. However, further evidence is needed regarding the comparative benefits and harms of the antihypertensive medications used to treat postpartum HTN. Large pragmatic trials, augmented by analysis of real-world data, are needed to evaluate the effect of postpartum HBPM on clinical event outcomes (not only process outcomes) and on the comparative effectiveness of alternative antihypertensive treatments. Given that lower dose MgSO4 regimens reduce Mg toxicity, and shorter regimens decrease urinary catheterization time, time to ambulation, time to breastfeeding, and time from delivery to contact with the infant, evidence is needed to identify MgSO4 regimens with the lowest effective dose and shortest effective duration that minimize side effects and toxicity but still prevent seizures among patients with preeclampsia with severe features.