Fetal and neonatal outcomes of pregnancies complicated by maternal sleep-disordered breathing: a systematic review

Introduction Maternal obstructive sleep apnea (OSA) and the broader spectrum of sleep-disordered breathing (SDB) during pregnancy may be associated with fetal and neonatal outcomes, but the literature is heterogeneous and uses clinically distinct exposure definitions. This systematic review aimed to evaluate associations between maternal SDB and fetal/neonatal outcomes while preserving differences in exposure ascertainment. Methods Following PRISMA 2020, the review was re-audited using updated PubMed and Web of Science searches, backward and forward citation searching, and ClinicalTrials.gov and WHO ICTRP registry searches. Exposures were classified as (1) objectively confirmed OSA/SDB, (2) administrative-code-defined OSA, and (3) symptom-, snoring-, or questionnaire-defined SDB risk. No meta-analysis was conducted because clinically comparable subsets were insufficient for quantitative pooling. Results The completed re-audit identified 64 eligible publications mapped to 53 conservative cohort/dataset families (55 if two probable overlap pairs are treated as separate): 22 objective/physiologic, 11 administrative/clinical, and 31 symptom/questionnaire publications. Objective studies showed mixed findings, with fetal-growth or neonatal signals in selected cohorts but null findings in several other objectively assessed populations. Administrative-code OSA was repeatedly associated with preterm birth and selected neonatal outcomes, although exposure misclassification and residual confounding remain important. Symptom/questionnaire studies were heterogeneous, with associations varying by symptom definition, timing, and outcome. Conclusion Current evidence does not establish a consistent fetal or neonatal risk pattern for objectively confirmed maternal OSA/SDB. Administrative-code and symptom/questionnaire evidence suggests associations for selected outcomes, particularly preterm birth, but should not be interpreted as a single homogeneous OSA effect. Systematic review registration https://www.crd.york.ac.uk/PROSPERO/ , identifier CRD420251110706.