Reproductive outcomes in male childhood cancer survivors: a linked cancer-birth registry analysis.

OBJECTIVE To compare the risk of reproductive and infant outcomes between male childhood cancer survivors and a population-based comparison group. DESIGN Retrospective cohort study. SETTING Four US regions. PARTICIPANTS Cancer registries identified males younger than 20 years diagnosed with cancer from 1973 to 2000. Linked birth certificates identified first subsequent live offspring (N = 470). Comparison subjects were identified from remaining birth certificates, frequency-matched on year and age at fatherhood, and race/ethnicity (N = 4150). MAIN EXPOSURE Cancer diagnosis before age 20 years. OUTCOME MEASURES Pregnancy and infant outcomes identified from birth certificates. RESULTS Compared with infants born to unaffected males, offspring of cancer survivors had a borderline risk of having a birth weight less than 2500 g (relative risk, 1.43 [95% confidence interval, 0.99-2.05]) that was associated most strongly with younger age at cancer diagnosis and exposure to any chemotherapy (1.96 [1.22-3.17]) or radiotherapy (1.95 [1.14-3.35]). However, they were not at risk of being born prematurely, being small for gestational age, having malformations, or having an altered male to female ratio. Overall, female partners of male survivors were not more likely to have maternal complications recorded on birth records vs the comparison group. However, preeclampsia was associated with some cancers, especially central nervous system tumors (relative risk, 3.36 [95% confidence interval, 1.63-6.90]). CONCLUSIONS Most pregnancies resulting in live births among partners of male childhood cancer survivors were not at significantly greater risk of complications vs comparison subjects. However, there remains the possibility that prior cancer therapy may affect male germ cells with some effects on progeny and on female partners.