Prenatal allostatic load and adverse pregnancy outcomes: a systematic review and meta-analysis

Background

Allostatic load (AL) denotes the cumulative physiological dysregulation resulting from chronic stress exposure. This systematic review and meta-analysis aimed to evaluate the association between prenatal AL and adverse pregnancy outcomes (APOs), and to synthesize current evidence to inform prenatal health strategies and potentially reduce the incidence of APOs. Methodology: This study systematically searched PubMed, Web of Science, Embase, PsycINFO, China National Knowledge Infrastructure, Wanfang, VIP China Science and Technology Journal Database, and SinoMed databases for relevant studies examining prenatal AL and APOs published from September 1993 to 22 June 2026. Two researchers independently screened the literature, extracted data, and assessed the risk of bias using the Newcastle-Ottawa scale. Meta-analysis was performed using R software (version 4.4.3). The study protocol is registered in PROSPERO (CRD420251076952).