Late Effects of Treatment for Childhood Cancer (PDQ®): Treatment - Health Professional Information [NCI] - Late Effects of the Reproductive System
Fertility was evaluated among the 5,149 female CCSS participants and 1,441 female siblings of CCSS participants, aged 15 to 44 years. The RR for ever being pregnant was 0.81 (95% CI, 0.73–0.90; P < .001) compared with female siblings. In multivariate models among survivors only, those who received a hypothalamic/pituitary radiation dose of greater than 3,000 cGy (RR = 0.61; 95% CI, 0.44–0.83) or an ovarian/uterine radiation dose greater than 500 cGy were less likely to have ever been pregnant (RR = 0.56 for 500–1000 cGy; 95% CI, 0.37–0.85; RR = 0.18 for >1000 cGy; 95% CI, 0.13–0.26). A summed alkylating agent dose score of 3 (RR = 0.72; 95% CI, 0.58–0.90; P = .003) or 4 (RR = 0.65; 95% CI, 0.45–0.96; P = .03) was associated with lower observed risk of pregnancy compared with those with no alkylating agent exposure. Those with a summed alkylating agent dose score of 3 or 4 or who were treated with lomustine or cyclophosphamide were less likely to have ever been pregnant. A follow-up study of the same cohort demonstrated impaired fertility in female survivors who received modest doses (22–27 Gy) of hypothalamic pituitary radiation and no or very low doses (<0.1 Gy) of ovarian radiation, providing support for the contribution of the role of luteal phase deficiency to infertility in some women.
Fertility may be impaired by factors other than the absence of sperm and ova. Conception requires delivery of sperm to the uterine cervix, patency of the fallopian tubes for fertilization to occur, and appropriate conditions in the uterus for implantation. Retrograde ejaculation occurs with a significant frequency in men who undergo bilateral retroperitoneal lymph node dissection. Uterine structure may be affected by abdominal irradiation. A study demonstrated that uterine length was significantly shorter in ten women with ovarian failure who had been treated with whole abdomen irradiation. Endometrial thickness did not increase in response to hormone replacement therapy in three women who underwent weekly ultrasound examination. No flow was detectable with Doppler ultrasound through either uterine artery of five women, and through one uterine artery in three additional women.
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.[48,49,52,53,54,55,56,57,58,59,60]
- 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.
- In a retrospective cohort analysis from the CCSS of 1,148 men and 1,657 women who had survived cancer, there were 4,946 pregnancies. Irradiation of the testes in men and pituitary gland in women and chemotherapy with alkylating drugs were not associated with an increased risk of stillbirth or neonatal death. Uterine and ovarian irradiation significantly increased the risk of stillbirth and neonatal death at doses higher than 10 Gy. For girls treated before menarche, irradiation of the uterus and ovaries at doses as low as 1 Gy to 2.49 Gy significantly increased the risk of stillbirth or neonatal death.
- 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.