Obstetrical and Perinatal Outcomes in Female Survivors of Childhood and Adolescent Cancer: A Population-Based Cohort Study

Abstract

Background: The likelihood of pregnancy and risk of obstetrical or perinatal complications is inadequately documented in female survivors of pediatric cancer. Methods: We assembled a population-based cohort of female survivors of cancer diagnosed at age 21 years and younger in Ontario, Canada, between 1985 and 2012. Survivors were matched 1:5 to women without prior cancer. Multivariable Cox proportional hazards and modified Poisson models assessed the likelihood of a recognized pregnancy and perinatal and maternal complications. Results: A total of 4062 survivors were matched to 20 308 comparisons. Median (interquartile range) age was 11 (4-15) years at cancer diagnosis and 25 (19-31) years at follow-up. By age 30 years, the cumulative incidence of achieving a recognized pregnancy was 22.3% (95% confidence interval [CI] = 20.7% to 23.9%) among survivors vs 26.6% (95% CI = 25.6% to 27.3%) among comparisons (hazard ratio = 0.80, 95% CI = 0.75 to 0.86). A lower likelihood of pregnancy was associated with a brain tumor, alkylator chemotherapy, cranial radiation, and hematopoietic stem cell transplantation. Pregnant survivors were as likely as cancer-free women to carry a pregnancy >20 weeks (relative risk [RR] = 1.01, 95% CI = 0.98 to 1.04). Survivors had a higher relative risk of severe maternal morbidity (RR = 2.31, 95% CI = 1.59 to 3.37), cardiac morbidity (RR = 4.18, 95% CI = 1.89 to 9.24), and preterm birth (RR = 1.57, 95% CI = 1.29 to 1.92). Preterm birth was more likely in survivors treated with hematopoietic stem cell transplantation (allogenic: RR = 8.37, 95% CI = 4.83 to 14.48; autologous: RR = 3.72, 95% CI = 1.66 to 8.35). Conclusions: Survivors of childhood or adolescent cancer are less likely to achieve a pregnancy and, once pregnant, are at higher risk for severe maternal morbidity and preterm birth.