For survivors who maintain fertility, numerous investigations have evaluated the prevalence of and risk factors for pregnancy complications in adults treated for cancer during childhood. Pregnancy complications including hypertension, fetal malposition, fetal loss/spontaneous abortion, preterm labor, and low birth weight have been observed in association with specific diagnostic and treatment groups.[46,47,48,50,51,52,53,54,55,56,57,58] In a study of 4,029 pregnancies among 1,915 women followed in the 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 radiation and 1.7-fold higher in those treated with pelvic radiation. Chemotherapy exposure alone did not increase risk of miscarriage. Compared with siblings, survivors were less likely to have live births, more likely to have medical abortions, and more likely to have low birth weight babies. In the same cohort, another study evaluated pregnancy outcomes of partners of male survivors. Among 4,106 sexually active males, 1,227 reported they sired 2,323 pregnancies, which resulted in 69% live births, 13% miscarriages, 13% abortions, and 5% unknown or in gestation at the time of analysis. Compared with partners of male siblings, there was a decreased incidence of live births (RR = 0.77), but no significant differences of pregnancy outcome by treatment. In the National Wilms Tumor Study, records were obtained for 1,021 pregnancies of more than 20 weeks duration. In this group, there were 955 single live births. Hypertension complicating pregnancy, early or threatened labor, malposition of the fetus, lower birth weight (<2,500 g), and premature delivery (<36 weeks) were more frequent among women who had received flank radiation, in a dose-dependent manner. Results from a Danish study confirm the association of uterine radiation with spontaneous but not other types of abortion. Thirty-four thousand pregnancies were evaluated in a population of 1,688 female survivors of childhood cancer in the Danish Cancer Registry. The pregnancy outcomes of survivors, 2,737 sisters, and 16,700 comparison women in the population were identified. No significant differences were seen between survivors and comparison women in the proportions of live births, stillbirths, or all types of abortions combined. Survivors with a history of neuroendocrine or abdominal radiation therapy had an increased risk of spontaneous abortion. Thus, the pregnancy outcomes of survivors were similar to those of comparison women with the exception of spontaneous abortion.
Progress in reproductive endocrinology has resulted in the availability of several options for preserving or permitting fertility in patients about to receive potentially toxic chemotherapy or radiation therapy. For males, cryopreservation of spermatozoa before treatment is an effective method to circumvent the sterilizing effect of therapy. Although pretreatment semen quality in patients with cancer has been shown to be less than that noted in healthy donors, the percentage decline in semen quality and the effect of cryodamage to spermatozoa from patients with cancer is similar to that of normal donors.[59,60,61,62] For those unable to bank sperm, newer technologies such as testicular sperm extraction may be an option. Further micromanipulative technologic advances such as intracytoplasmic sperm injection and similar techniques may be able to render sperm extracted surgically, or even poor-quality cryopreserved spermatozoa from cancer patients, capable of successful fertilization.