Systematic review links preterm delivery to increased stroke risk in parous women over 8 to 57 years

BACKGROUND: Adverse pregnancy outcomes are linked to increased risk of maternal cardiovascular disease. However, the association between preterm delivery (PTD) and long-term risk of stroke in the mother remains uncertain, particularly in the case of spontaneous PTD. METHODS: A systematic review and meta-analysis were performed to provide an up-to-date synthesis of the evidence on the association between PTD and long-term maternal stroke. PubMed, CINAHL, and Web of Science were searched for relevant articles published between January 1, 2000, and May 6, 2025. Eligible studies included cohort and case-control studies examining populations of parous women. Primary exposure was defined as any PTD; secondary exposures were spontaneous PTD and medically indicated PTD. The primary outcome was defined as any stroke; secondary outcomes were ischemic and hemorrhagic stroke. Two reviewers screened studies, extracted data, and performed quality assessments. Pooled unadjusted and adjusted effect estimates (as defined by the original study) were calculated separately using random effects inverse variance models. RESULTS: Eleven thousand twenty-five studies were screened for eligibility. Across 21 studies including a total of 8.7 million participants, PTD was consistently associated with increased stroke risk. The follow-up period ranged from 8 to 57 years. The primary meta-analysis demonstrated a positive association between any PTD and any stroke (adjusted risk ratio [aRR], 1.66 [95% CI, 1.34-2.05]). A high level of heterogeneity was observed (=97%, =0.15), possibly due to variations in exposure definition, outcome ascertainment, and follow-up durations. Spontaneous PTD (aRR, 1.37 [95% CI, 1.15-1.64]) and medically indicated PTD (aRR, 2.08 [95% CI, 1.70-2.54]) were associated with any stroke. PTD was positively associated with ischemic (aRR, 1.59 [95% CI, 1.45-1.75]) and hemorrhagic stroke (aRR, 1.44 [95% CI, 1.06-1.94]). CONCLUSIONS: Women who have experienced a PTD, including spontaneous PTD, may be at increased risk of stroke in later life. These women may benefit from targeted cardio-metabolic preventive interventions postpartum to reduce their risk.