Adverse Obstetric Outcomes Among Early-Onset Cancer Survivors in Finland.

OBJECTIVE

To evaluate risk of adverse obstetric outcomes and operative deliveries in female cancer survivors (diagnosed younger than 35 years of age) compared with female siblings of survivors.

METHODS

Nationwide cancer and birth registries were merged to identify 1,800 first postdiagnosis deliveries of female cancer survivors and 7,137 first deliveries of female siblings between January 1987 and December 2013. Multiple unconditional logistic regression models were used to estimate the risk for adverse obstetric outcomes and operative deliveries adjusting for maternal age, year of delivery, gestational age, and smoking.

RESULTS

We found a significantly elevated risk for induction of labor, 19.1% in survivors and 15.6% in siblings (odds ratio [OR] 1.17, 95% confidence interval [CI] 1.02-1.35) and cesarean delivery, 23.6% in survivors and 18.6% in siblings (OR 1.15, 95% CI 1.01-1.31) among cancer survivors compared with female siblings. The risks of instrumental vaginal delivery, malpresentation, placental pathologies, and postpartum hemorrhage were not, however, elevated among cancer survivors. The highest risks of adverse obstetric outcomes were seen among women treated in their childhood (aged 0-14 years).

CONCLUSION

Cancer survivors have a small but statistically increased risk for induction of labor and cesarean delivery compared with siblings without a history of cancer. Our findings indicate that pregnancies in cancer survivors are typically uncomplicated and cancer survivors should not be discouraged to have children after their cancer is cured.

LEVEL OF EVIDENCE: II.