Many survivors of childhood cancer previously treated with cytotoxic therapy will remain fertile, and, therefore, pregnancy outcomes and the risk of cancer or genetic disease in offspring must be addressed. Young women who have been exposed to radiotherapy below the diaphragm are also at risk of impaired uterine development, which can adversely affect pregnancy outcomes, often resulting in premature labor and low birth-weight infants. The magnitude of the risk is related to the radiotherapy field, total dose and fractionation schedule. Female long-term sur vivors treated with total body irradiation and marrow transplantation are at risk for impaired uterine growth and blood flow, and, if pregnancy is achieved, for early pregnancy loss and premature labor. Despite standard hormone replacement, the uterus of the childhood cancer survivor may be impaired in its development and measure only 40% of normal adult size, the ultimate uterine volume correlating with the age at which radiotherapy was received [18,34-36].
With more childhood cancer survivors retaining fertility, pregnancy outcome data is now available. Of 4,029 pregnancies occurring among 1,915 women followed in the Childhood Cancer Survivor Study (CCSS), there were 63% live births, 1% stillbirths, 15% miscarriages, 17% abortions and 3% unknown or in gestation. Risk of miscarriage was 3.6-fold higher in women treated with craniospinal radiotherapy and 1.7-fold higher in those treated with pelvic radiotherapy. Chemotherapy exposure alone did not increase the risk of miscarriage. Compared with siblings, however, survivors were less likely to have live births and more likely to have medical abortions and low birth-weight babies .
In the National Wilms Tumor Study, records were obtained for 427 pregnancies of >20 weeks duration. In this group, there were 409 single and 12 twin live births. Early or threatened labor, malposition of the fetus, lower birth-weight (<2500 g) and premature delivery (<36 weeks) were more frequent among women who had received flank radiotherapy, in a dose-dependent manner .
Preservation of fertility and successful pregnancies may occur following HSCT. Sanders and colleagues evaluated pregnancy outcomes in a group of females treated with bone marrow transplant. Among 116 treated before puberty and 23 treated after the onset of puberty who retained ovarian function, 32 (28%) and 9 (30%), respectively, became pregnant. Of the 32 pregnancies in those treated with TBI 50% (16) resulted in early termination, compared with a 21 % prevalence of early termination in those treated with cyclophosphamide alone. There were no pregnancies among the women treated with busulfan and cyclophosphamide .
For childhood cancer survivors who have offspring, there is the concern about congenital anom alies, genetic disease or risk of cancer in the offspring. In the report from the National Wilms Tumor Group, congenital anomalies were marginally increased in the offspring of females who had received flank radiotherapy . However, this risk was not observed in a study of 247 offspring of 148 cancer survivors treated at a single institution , or in several larger cohort studies. In a study that compared a group of 2,198 offspring from adult survivors treated for childhood cancer between 1945 and 1975 with a group of 4,544 offspring from sibling controls, there were no differences in the proportion of offspring with cytogenetic syndromes, single-gene defects or simple malformations. Nor was there an effect with respect to the type of childhood cancer treatment used and the occurrence of genetic disease in the offspring . Similar results were reported in a study of 5,847 offspring of survivors of childhood cancers treated in five Scandinavian countries. In the absence of a hereditary cancer syndrome (such as hereditary retinoblastoma), there was no increased risk of cancer . Further follow-ups are needed to determine whether patterns of cancer or genetic disease in offspring change with changes in cancer treatments, further elapsed time and studies of greater numbers of offspring.
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A Beginner's Guide to Healthy Pregnancy. If you suspect, or know, that you are pregnant, we ho pe you have already visited your doctor. Presuming that you have confirmed your suspicions and that this is your first child, or that you wish to take better care of yourself d uring pregnancy than you did during your other pregnancies; you have come to the right place.