Risk of being born preterm in offspring of survivors with childhood or adolescent central nervous system tumor in Sweden.

An increasing number of patients with central nervous system (CNS) tumor could survive to reproductive age. However, it is largely unknown whether the history of CNS tumor might affect pregnancy outcome. We aimed to explore the risk of being born preterm among children of CNS tumor survivors. By linking several nationwide registers in Sweden, we identified 1,369 children whose parents were childhood or adolescent CNS tumor survivors. Children whose parents did not have CNS tumor were matched randomly with a 5:1 ratio to generate the reference group. Conditional logistic regression was used to calculate the odds ratio (OR) and 95% confidence interval (CI). The prevalence of preterm birth (PTB) was 6.9% among children of survivors with CNS tumor and 5.2% among the matched controls. Children of survivors had an increased risk of PTB (adjusted OR = 1.29, 95%CI 1.01-1.65) compared to the matched controls. This risk was increased specifically among offspring of those diagnosed in childhood (adjusted OR = 1.53, 95%CI 1.14-2.06) but not adolescence (adjusted OR = 0.89, 95%CI 0.56-1.41). For families with more than one child, the risk was slightly lower among the second child as compared to the first child. The risk was negatively associated with time interval between parental diagnosis and childbirth. Parental medulloblastoma and ependymoma were most strongly associated with a higher risk of PTB. Children of survivors with CNS tumor experienced an elevated risk of PTB. However, the risk diminishes gradually after parental diagnosis of CNS tumor. Offspring of childhood CNS tumor survivors and medulloblastoma or ependymoma survivors may have the highest risk of PTB.