Influence of cancer in pregnancy on obstetric and neonatal outcomes: an observational retrospective cohort study.

Objective: The study aimed to review the oncological characteristics and treatment of pregnancy-associated cancers and analyze the obstetric and neonatal outcomes to provide evidence-based recommendations for reproductive function preservation, oncological treatment, and obstetric management.

Methods: We conducted an observational retrospective cohort study among pregnant patients with cancer in 7 Chinese tertiary A hospitals from 2003 to 2021. We conducted multiple logistic regression to determine the influence of various factors on preterm birth and small-for-gestational-age infants, log-binomial regression to analyze temporal changes, and χ² tests to explore the effects of cancer type/treatment.

Results: Of 204 women, 17% terminated their pregnancies; 59% received pre-delivery treatment. Every 6 years, the rates of pregnancy termination (relative risk [RR]=0.48; 95% confidence interval [CI]=0.35-0.67) and iatrogenic preterm births (RR=0.73; 95% CI=0.54-0.98) reduced, and that of pre-delivery treatment increased, mainly due to increased rates of surgery (RR=1.87; 95% CI=1.31-2.67). Maternal systemic diseases were related to small-for-gestational-age infants (odds ratio [OR]=12.02; 95% CI=1.82-79.43). Chemotherapy with taxanes plus platinum-based agents was related to adverse obstetric outcomes (OR=1.87; 95% CI=1.42-2.46; p<0.05). Thyroid (OR=0.36; 95% CI=0.22-0.57) and ovarian cancer (OR=0.70; 95% CI=0.50-0.98) were associated with fewer cesarean sections. Thyroid cancer was associated with fetal growth restriction (OR=5.21; 95% CI=1.21-22.55).

Conclusion: Rates of pregnancy termination in cancer declined. Taxane plus platinum-based chemotherapy was associated with adverse obstetric outcomes. Cancer type influenced outcomes.

Trial registration: Chinese Clinical Trial Register Identifier: ChiCTR2100044292.