Stillbirth, early death and neonatal morbidity among offspring of female cancer survivors

Background. Increased awareness of the adverse effects of cancer treatments has prompted the development of fertility preserving regimens for the growing population of cancer survivors who desire to have children of their own. Material and methods. We conducted a registry-based study to evaluate the risk of stillbirth, early death and neonatal morbidity among children of female cancer survivors (0-34 years at diagnosis) compared with children of female siblings. A total of 3501 and 16 908 children of female cancer patients and siblings, respectively, were linked to the national medical birth and cause-of-death registers. Results. The risk of stillbirth or early death was not significantly increased among offspring of cancer survivors as compared to offspring of siblings: the risk [Odds Ratio (OR)] of early neonatal death, i.e. mortality within the first week was 1.35, with a 95% confidence interval (CI) of 0.58-3.18, within 28 days 1.40, 95% CI 0.46-4.24 and within the first year of life 1.11, 95% CI 0.64-1.93 after adjustment for the main explanatory variables. All these risk estimates were reduced towards one after further adjustment for duration of pregnancy. Measures of serious neonatal morbidity were not significantly increased among the children of survivors. However, there was a significant increase in the monitoring of children of cancer survivors for neonatal conditions (OR 1.56, 95% CI 1.35-1.80), which persisted even after correcting for duration of pregnancy, that might be related to parental cancer and its treatment or increased surveillance among the children. Conclusion. Offspring of cancer survivors were more likely to require monitoring or care in a neonatal intensive care unit, but the risk of early death or stillbirth was not increased after adjustment for prematurity. Due to the rarity of the mortality outcomes studied, collaborative studies may be helpful in ruling out the possibility of an increased risk among offspring of cancer survivors.