Obstetric Complications and Pregnancy Outcomes in Cancer Survivors: A Systematic Review and Meta-Analysis

<b>Background:</b> With advances in cancer diagnosis and therapy, survival after childhood and young-adult cancers has improved markedly. As survivorship extends, understanding long-term health sequelae, including obstetric outcomes, has become increasingly important. However, the reproductive safety of pregnancy following cancer remains insufficiently characterized. This systematic review and meta-analysis aims to provide a comprehensive evaluation of obstetric outcomes following pregnancy in survivors of childhood and young-adult cancers. <b>Methods:</b> We conducted a systematic review and meta-analysis (PROSPERO: CRD42024573707) of PubMed, Embase, and Cochrane databases to identify controlled studies assessing obstetric complications among female cancer survivors, published between 1 January 2000 and 31 June 2024. Random effects meta-analyses were used to estimate pooled risk ratios (RRs) with 95% confidence intervals (CIs). Heterogeneity, subgroup analyses, and meta-regression were performed to identify sources of variation. <b>Results:</b> Of 6032 records screened, 16 studies involving 89,123 survivors and 21,569,191 controls were included. Cancer survivorship was associated with higher risks of preeclampsia (RR 1.37, 95% CI 1.17-1.62), gestational diabetes (RR 1.29, 95% CI 1.05-1.59), and miscarriage (RR 1.16, 95% CI 1.01-1.35), but not with anemia in pregnancy (RR 1.16, 95% CI 0.98-1.39) or hypertensive disorders (RR 1.21, 95% CI 0.99-1.49). Cancer type emerged as a potential prognostic factor for preeclampsia. <b>Conclusions:</b> Female cancer survivors are at significantly increased risk of major obstetric complications, underscoring the need for anticipatory preconception counselling and enhanced antenatal surveillance. Future research should delineate cancer- and treatment-specific risks to inform precision reproductive care in this growing survivorship population.