Aspirin prophylaxis for superimposed preeclampsia in women with chronic hypertension: a retrospective cohort study
In brief
Aspirin cuts superimposed preeclampsia risk by about 80% in chronic hypertension
In a Chinese cohort of 504 pregnancies with chronic hypertension, women who started low-dose aspirin between 8 and 20 weeks had roughly an 80% lower odds of developing superimposed preeclampsia, and a 90% lower odds of early-onset disease. The drug also lowered rates of preterm birth and serious neonatal complications without raising bleeding risk, though the optimal dose needs prospective testing.
- Journal
- Pregnancy hypertension (Q1)
- Published
- 12 September 2026
- Study design
- Prospective / inception cohort
- Evidence level
- Level 2, Moderate (CEBM 2b)
- Authors
- Tianying Zhu, Shengnan Yu, Jing Tian, Junnan Ma, Yunping Wu, Min Xie, et al.
- PMID
- 42731374
- DOI
- 10.1016/j.preghy.2026.101517
Why clinicians should know about it
- Picked for Obstetrics and Gynecology (paper of the day, 15 September 2026): Retrospective cohort, aspirin prophylaxis in chronic hypertension
Abstract
OBJECTIVE: Chronic hypertension (CHT) is a major risk factor for superimposed preeclampsia, but the effectiveness of aspirin prophylaxis in women with CHT remains uncertain, particularly in Asian populations. We evaluated the association of aspirin use with superimposed preeclampsia and related maternal and perinatal outcomes in Chinese women with CHT. METHODS: We conducted a retrospective cohort study of 504 singleton pregnancies with CHT initiating prenatal care at 8-20 weeks of gestation across two coordinated tertiary hospitals (2013-2025). Participants were stratified by aspirin (n = 307) or no aspirin (n = 197). Multivariable logistic regression adjusted for confounders, and dose effects were explored. RESULTS: Compared with no aspirin exposure, aspirin use was associated with lower adjusted odds of superimposed preeclampsia (adjusted odds ratio [aOR], 0.183 [95% CI, 0.119-0.280]), early-onset preeclampsia before 34 weeks (aOR, 0.092 [95% CI, 0.050-0.168]), and preterm preeclampsia before 37 weeks (aOR, 0.142 [95% CI, 0.087-0.231]; all P < 0.001). Aspirin use was also associated with lower risks of preterm birth, placental abruption, thrombocytopenia, small for gestational age, neonatal asphyxia, neonatal intensive care unit admission, respiratory support, hypoxic-ischemic encephalopathy, stillbirth, and perinatal death. In exploratory within-group analyses, higher aspirin dose was associated with lower frequencies of superimposed preeclampsia and several adverse maternal and neonatal outcomes. Aspirin use was not associated with higher rates of cesarean delivery or postpartum hemorrhage. CONCLUSION: In Chinese women with CHT, early-to-mid pregnancy aspirin use significantly reduces superimposed preeclampsia odds and adverse perinatal outcomes without increasing bleeding risks. The potential dose-response pattern requires prospective validation.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.