A 33?year?old woman, gravida 1, para 0, came to the hospital with the chief complaint of severe dysmenorrhea and infertility. Her menstrual cycle was regular, bleeding moderately for 3–5 days with an interval of 30 days. She was diagnosed with ectopic pregnancy and received the left salpingectomy in September 2014. Intraoperative exploration showed a slightly enlarged retroverted uterus with a wide fundus and a normal right fallopian tube. As a further examination of infertility, hysterosalpingography was done in January 2016, which showed a unicuate uterus (left) with an obstructed unilateral fallopian tube. She was referred to the Department of Obstetrics and Gynecology at Peking Union Medical College Hospital in February 2016. Her basic body temperature showed biphasic patt. The sperm test of her husband was normal. Physical examination indicated two vaginal orifices in the vestibule, with a vertical septate lying in between. The left lateral vaginal lumen could be easily expanded and speculated, and a normal cervix was seen at its top. In contrast, the cervix was unable to be seen through the right lateral vaginal lumen, which was narrow and difficult to be exposed or inspected. Pelvic ultrasound scan showed that the uterus was 4.7 cm × 6.0 cm × 3.6 cm in size, along with the Y?shaped endometrium of 0.8 cm in thickness, and a normal echo in the muscular layer. No abnormalities were found at the bilateral adnexa areas or pelvic cavity. Besides, the bilateral renal areas and ureters were found normal in the ultrasound scan as well.