Unanticipated pregnancy with intrauterine growth retardation after radiation-induced ovarian failure. A case report.

BACKGROUND: Ovarian failure is common after pelvic irradiation and is dependent upon radiation dose and patient age. This case report demonstrates the resumption of ovulation and pregnancy subsequent to this diagnosis.

CASE: An enlarging abdominal mass was noted in a 28-year-old female 20 months after resection of a pelvic hemangiopericytoma. She had received postoperative adjuvant hemipelvic radiotherapy and subsequently developed amenorrhea and symptoms of hypoestrogenism. Serum follicle-stimulating hormone (FSH) was elevated. In light of the diagnosis of ovarian failure, the finding of an intrauterine pregnancy on an abdominal computed tomography scout film, performed to rule out a recurrence of the primary tumor, was unexpected.

CONCLUSION: While amenorrhea and elevation in serum gonadotropin levels are common after pelvic irradiation, the clinician must be cognizant of the potential for resumption of ovulation after radiotherapy. The diagnosis of ovarian failure should be based on more than a single serum FSH level. Further, radiation changes in the endometrium and myometrium as well as in uterine blood flow may have an adverse effect on pregnancy outcome. We suspect these effects had an etiologic influence on the fetal growth retardation in this pregnancy.