Spontaneous Abortion in a Danish Population-Based Cohort of Childhood Cancer Survivors

Abstract
Purpose Radiation induces germ-cell mutations in experimental animals that result in adverse pregnancy outcomes, as does uterine damage caused by high-dose radiotherapy. We assessed the risks for spontaneous abortion and stillbirths among cancer survivors who received radiotherapy and subsequently became pregnant. Patients and Methods We identified 1,688 female survivors of childhood cancer in the Danish Cancer Registry. Radiation doses to the ovary and uterus were characterized as high to low. The pregnancy outcomes of survivors, 2,737 sisters, and 16,700 comparison women in the population were identified from nationwide registries. The proportions of pregnancies among survivors that resulted in a livebirth, stillbirth, or abortion were compared with the equivalent proportions among the two comparison groups, and proportion ratios (PRs) were computed with sisters as referent. Results More than 34,000 pregnancies were evaluated, 1,479 of which were among cancer survivors. No significant differences were s...