title: Effects of letrozole in combination with low-dose intramuscular injection of human menopausal gonadotropin on ovulation and pregnancy of 156 patients with polycystic ovary syndrome.
abstract: OBJECTIVE
  To explore the effects of letrozole (LE) in combination with low-dose intramuscular injection of human menopausal gonadotropin (HMG) on the ovulation induction and pregnancy of patients with polycystic ovary syndrome (PCOS).
  
  
  METHODS
  A total of 156 patients with PCOS infertility were randomly divided into an LE group, a clomiphene citrate (CC) group and an LE + HMG group (n= 52). LE and CC were orally taken according to the prescribed dosage on the 3rd-5th days of menstruation respectively, and 75 IU HMG was given through intramuscular injection. The ovulation induction parameters and pregnancy outcomes were observed.
  
  
  RESULTS
  The number of ovulation cycle of LE + HMG group was significantly higher than that of LE group (χ2=8.451, P<0.001). After injection of human chorionic gonadotropin, both endometrial thickness and number of mature follicles of LE + HMG group were significantly higher than those of other two groups (P<0.001), and the daily estradiol (E2) level was also higher (q=4.531, P<0.05). The pregnancy rate of LE + HMG group was 55.7%, which exceeded those of other two groups (compared to LE group, χ2=4.012, P<0.05). In LE + HMG group, the average medication cycle of clinically pregnant patients was (2.9 ± 0.3) weeks, which was significantly shorter than those of CC and LE groups (F=17.241, P<0.001).
  
  
  CONCLUSIONS
  The regimen using LE in combination with low-dose intramuscular injection of HMG has satisfactory therapeutic effects on ovulation induction, short medication cycle and high clinical pregnancy rate, which is promising for treating patients with PCOS infertility.
authors.affiliation: Zhihua Chen, Department of Gynecology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, P. R. China.
authors.forename: Zhihua
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Mengzhen Zhang, Department of Gynecology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, P. R. China.
authors.forename: Mengzhen
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Yuhuan Qiao, Department of Gynecology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, P. R. China.
authors.forename: Yuhuan
authors.initials: Y
authors.lastname: Qiao
authors.affiliation: Junjuan Yang, Department of Obstetrics and Gynecology, Women and Infants Hospital of Zhengzhou, Zhengzhou 450012, P. R. China.
authors.forename: Junjuan
authors.initials: J
authors.lastname: Yang
keywords: human menopausal gonadotropin; letrozole; ovulation; polycystic ovary syndrome; pregnancy