Outcomes of in vitro fertilization for women with thyroid cancer: a case report.

BACKGROUND: Pregnancy is a major concern when treating thyroid cancer (TC) in women of childbearing age. The impact of thyroidectomy on pregnancy outcomes remains controversial, and there are few reports on the management of infertile women with TC who require assisted reproductive technology (ART). We present an infertile woman with TC who successfully underwent in vitro fertilization (IVF) and achieved favorable outcomes. CASE PRESENTATION: A 36-year-old woman requested ART after bilateral salpingectomy. Papillary thyroid carcinoma (PTC) was detected during the pre-IVF examination, and the patient refused surgical treatment for subjective reasons. Levothyroxine was administered to control thyroid stimulating hormone (TSH) levels as the patient's TSH levels were above the upper limit. She was treated with the flexible antagonist protocol for controlled ovarian stimulation (COS), and gonadotropin was administered for 9 days, with a total dose of 2250 IU. Oocyte retrieval was performed 36 h after recombinant human chorionic gonadotropin (HCG) administration and 13 oocytes were retrieved. Conventional IVF insemination was performed and 5 usable embryos were ultimately obtained. Artificial endometrial preparation was performed for frozen embryo transfer (FET), and clinical pregnancy was achieved after transferring a 4CB blastocyst. During COS, FET, and pregnancy, thyroid hormones and neck ultrasound of the patient were closely monitored, and the dose of levothyroxine was adjusted to maintain TSH levels below 2.000 mU/L during pregnancy and below 4.000 mU/L pre- and postpartum. Finally, at 39 weeks of gestation, the patient successfully delivered a baby boy by cesarean section. No maternal or neonatal complications were observed, and the PTC remained stable until 6-month postpartum. CONCLUSION: Thyroid surgery for infertile women complicated with PTC may be deferred after completing COS, embryo transfer, and pregnancy. No adverse effects of PTC on IVF outcomes, obstetrical and neonatal outcomes were observed in this case.