A study involving nurses who worked with patients exposed to cytotoxic drugs found evidence of minor effects on fertility, although there was no indication of serious effects. There are limited data on the potential adverse effects of chronic low-level exposure to cytotoxic drugs used in cancer chemotherapy, although these agents are known to have high reproductive toxicity at therapeutic doses. The authors therefore carried out this study to quantify the effect on reproduction of occupational exposure to cytotoxic drugs, which is known to be predominantly via dermal absorption. They used self-administered questionnaires to compare outcomes between cytotoxic drug exposed nurses with those not exposed: exposure was defined as working in an oncology department for at least two months over the study period of 1990 to 1997; controls had worked in orthopaedics, obstetrics and gynaecology, or surgery over the same period. Questions related to pregnancy outcome, work-related exposures, and lifestyle. Several methods were used to quantify likely exposure levels. Primary outcome was time to first pregnancy, and other reproductive effects were studied as secondary outcomes.

A total of 4393 nurses (of 5546 eligible) completed the questionnaires and 2426 had at least one pregnancy or were trying to become pregnant. A significant proportion of the control group had to be excluded because they reported exposure to anaesthetic gases, and the final analysis involved 663 unexposed, 324 with background exposure, 178 with low exposure, 177 with median exposure and 177 with high exposure.

High exposure was associated with a longer time to conceive compared to controls, and exposure was also associated with small increases in risk of premature delivery and low birth weight. There was no association between exposure and malformations, spontaneous abortion, stillbirth, and sex of offspring. Based on their results, the authors conclude that low levels of exposure to cytotoxic drugs, as experienced occupationally by nurses, is associated with minor reproductive toxicity. There is an indication of a dose-response effect. They suggest that these results should inform awareness amongst people working with cytotoxic drugs.