Full-term live birth in a woman with 17α-hydroxylase and 17,20-lyase deficiency with assisted reproductive technology: a case report.

BACKGROUND: 17α-hydroxylase deficiency, which is caused by a CYP17A1 gene mutation, is a rare type of congenital adrenocortical hyperplasia that mainly manifests as hypertension, hypokalaemia and sexual dysplasia. To date, few pregnancies associated with this syndrome have been reported. CASE PRESENTATION: We describe a 35-year-old Chinese woman with nonclassical congenital adrenal hyperplasia (NCCAH) due to 17α-hydroxylase/17,20-lyase deficiency who achieved pregnancy after in vitro fertilization (IVF) and frozen-thawed embryo transfer. She had secondary amenorrhea since she was 27, and subsequently, high level of progesterone in the follicular phase was found during a blood test. A compound heterozygous mutation was found in the CYP17A1 gene, c.1263G > A and c.985_987delinsAA. The patient was given standardized treatment with dexamethasone. Due to ovulation disorder, IVF was performed. She underwent whole embryo vitrification freezing. Frozen-thawed embryo transplantation was performed following the artificial cycle protocol of endometrium preparation, resulting in a singleton pregnancy. At 39 weeks and 1 day of gestation, caesarean section was performed due to the breech position of the foetus. CONCLUSION: A high level of progesterone reduces endometrial receptivity. Standardized treatment with dexamethasone and frozen-thawed embryo transfer with an artificial cycle protocol of endometrium preparation should be the choice for infertile female patients with CYP17A1 deficiency.