Chemotherapy for cancer in childhood can affect the fertility of men and women or even cause birth defects.
For men, drugs like procarbazine, chlorambucil and cyclophosphamide have been shown to be toxic to the testes; sterility can be caused in the majority of male patients after a cumulative dose of 18 grams of alkylating agents like cyclophosphamide (although some begin producing sperm again after 18 months).
For women, chemotherapy can cause ovarian failure and premature menopause in virtually any woman treated, according to some studies. (CA-A Cancer Journal for Clinicians, July/August 1990.)
This could be cause for concern as 5 per cent of cancer patients are under 34.
As for those who do go on to conceive children, a study conducted in New York found that of 202 pregnancies among 306 patients, 8 per cent of the children of women and 7.9 per cent of the children of the men had birth defects. Although this was not considered statistically significant, the study did show that congenital cardiac defects were identified in 10 per cent of the children of women who'd been treated with dactinomycin, compared to 0.6 among a control population.