This corresponds to about 3 weeks in mice. The researchers found fewer pregnancies in mice that had follicles in a mature stage when they received chemotherapy. There was also a highly significant rate of abortion and 10 times the rate of malformation across the treated groups compared with the control group, with a peak of one third of embryos malformed in the group of mice treated during early stages of follicular growth. As the interval between exposure and breeding lengthened, the malformation rate gradually fell, reaching normal levels in the group mated 12 weeks after treatment. It is clear that early fertilisation postchemotherapy can result in a high rate of pregnancy failure and malformation.
More research is needed to know whether the same applies to humans.
Until we know more, it would seem advisable to monitor the pregnancy outcome of all cancer patients who undergo IVF and embryo cryopreservation after chemotherapy, and possibly to screen fetuses and babies for chromosomal aberrations and birth defects. He also suggested that women should avoid becoming pregnant too soon after chemotherapy. This applies not only to cancer patients, but also to women with autoimmune diseases such as lupus, which are also sometimes treated with low, nonsterilising doses of cyclophosphamide. The information provided through OncoLink should not be used for diagnosing or treating a health problem or a disease. It is not a substitute for professional care.