To examine several cases of unusual and unexpected pregnancy in the female partners of men treated with brachytherapy for cancer of the prostate.

Self-reported pregnancy of partners of patients who had had prostate brachytherapy was assessed. The dosimetry to the testicles and sperm counts were used to examine the feasibility of pregnancy in the partners.

Three reported cases of pregnancy showed the men to have viable counts of within several or all of the parameters of the World Health Organisation criteria for normal semen analysis.

These cases provide a cautionary tale and suggest that all men being treated with prostate brachytherapy should be counselled about the possibility of continued fertility. Documentation of this 'risk' on the consent form will allow for proper discussion of this issue in a clinical and medicolegal context. The key to addressing this problem is to propagate much better patient information. The topic should be addressed clearly in information booklets for the patients. Prostate brachytherapy may allow for pregnancy to be achieved in the fertile partners of patients, even after full radiation treatment of the patient.