Abstract: Objective：To investigate the genetic diagnosis and IVF-ET treatment of congenital adrenal hyperplasia (CAH). Methods：Clinical manifestations, chromosome examinations, biochemistry and steroid hormone measurements were collected in a patient with CAH who had primary infertility. Genotyping was performed using direct gene sequencing. Corticosteroids replancement and IVF-ET therapy were performed. Results：This patient was diagnosed as a CAH due to 21-hydroxylase deficiency (21-OHD) by a heterozygous mutation of CYP21A2 gene. After successful pregnancy with IVF-ET, the patient was given glucocorticoid intervention and prenatal diagnosis. A healthy baby boy was delivered at term. Conclusions：Genotyping is an effective method for CAH genetic diagnosis and prenatal diagnosis. Reducing androgen and progesterone during IVF-ET treatment of CAH patients can improve the pregnant outcome.

Key words: Adrenocortical hyperfunction, Infertility, female, Fertilization in vitro, Congenital adrenal hyperplasia, 21-hydroxylase deficiency, Genotyping