Pregnancy-Associated Cancer: A Systematic Review and Meta-Analysis.

This study aimed to systematically evaluate and quantify the risk of adverse maternal and neonatal outcomes in patients with pregnancy-associated cancer (PAC). This study was conducted from February 13, 2021, through July 24, 2023. A systematic search of MEDLINE, Embase, Web of Science Core Collection, Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials was conducted to identify studies reporting outcomes for patients with PAC. The study was registered on PROSPERO. Two reviewers independently conducted screening, data extraction, and quality assessment. The associations were quantified using random-effects meta-analysis. The initial search produced 29,401 titles and abstracts, after which 147 unique full-text articles were screened, of which 22 articles with 59,190 pregnancies with PAC from 70,097,167 births were included in the meta-analysis. Women with PAC were at significantly increased risk of cesarean deliveries (risk ratio [RR], 1.58; 95% CI, 1.31-1.89), preterm birth (RR, 3.07; 95% CI, 2.37-3.98), venous thromboembolism (RR, 6.76; 95% CI, 5.08-8.99), and maternal death (RR, 41.58; 95% CI, 20.38-84.83). The only outcome with reduced risk was instrumental mode of delivery (RR, 0.67; 95% CI, 0.52-0.87). Pregnancy-associated cancer increases risk of adverse outcomes, including a 7-fold risk of venous thromboembolism and a 42-fold risk of maternal death. Further research is required to better understand the mechanisms leading to these adverse outcomes, especially for women who are not diagnosed until the postpartum period. Affected women should have counseling regarding their increased risk of adverse outcomes.