Clin Exp Reprod Med.  2018 Sep;45(3):135-142. 10.5653/cerm.2018.45.3.135.

Early gonadotropin-releasing hormone antagonist protocol in women with polycystic ovary syndrome: A preliminary randomized trial

  • 1Department of Obstetrics and Gynecology, Seoul National University College of Medicine, Seoul, Korea.
  • 2Her Yoo Jae Hospital, Goyang, Korea.
  • 3Institute of Reproductive Medicine and Population, Medical Research Center, Seoul National University College of Medicine, Seoul, Korea.
  • 4Department of Obstetrics and Gynecology, Cheil General Hospital and Women's Healthcare Center, Dankook University College of Medicine, Seoul, Korea.
  • 5Department of Obstetrics and Gynecology, CHA Bundang Fertility Center, CHA University School of Medicine, Seongnam, Korea.
  • 6Department of Obstetrics and Gynecology, CHA Gangnam Fertility Center, CHA University School of Medicine, Seoul, Korea.


To prospectively evaluate the efficacy and safety of a fixed early gonadotropin-releasing hormone (GnRH) antagonist protocol compared to a conventional midfollicular GnRH antagonist protocol and a long GnRH agonist protocol for in vitro fertilization (IVF) in patients with polycystic ovary syndrome (PCOS).
Randomized patients in all three groups (early antagonist, n=14; conventional antagonist, n=11; long agonist, n=11) received 21 days of oral contraceptive pill treatment prior to stimulation. The GnRH antagonist was initiated on the 1st day of stimulation in the early antagonist group and on the 6th day in the conventional antagonist group. The GnRH agonist was initiated on the 18th day of the preceding cycle. The primary endpoint was the number of oocytes retrieved, and the secondary endpoints included the rate of moderate-to-severe ovarian hyperstimulation syndrome (OHSS) and the clinical pregnancy rate.
The median total number of oocytes was similar among the three groups (early, 16; conventional, 12; agonist, 19; p=0.111). The early GnRH antagonist protocol showed statistically non-significant associations with a higher clinical pregnancy rate (early, 50.0%; conventional, 11.1%; agonist, 22.2%; p=0.180) and lower incidence of moderate-to-severe OHSS (early, 7.7%; conventional, 18.2%; agonist, 27.3%; p=0.463), especially among subjects at high risk for OHSS (early, 12.5%; conventional, 40.0%; agonist, 50.0%; p=0.324).
In PCOS patients undergoing IVF, early administration of a GnRH antagonist may possibly lead to benefits due to a reduced incidence of moderate-to-severe OHSS in high-risk subjects with a better clinical pregnancy rate per embryo transfer. Further studies with more subjects are required.


Gonadotropin-releasing hormone antagonist; In vitro fertilization; Ovarian hyperstimulation syndrome; Polycystic ovary syndrome; Pregnancy

MeSH Terms

Embryo Transfer
Fertilization in Vitro
Gonadotropin-Releasing Hormone*
Ovarian Hyperstimulation Syndrome
Polycystic Ovary Syndrome*
Pregnancy Rate
Prospective Studies
Gonadotropin-Releasing Hormone
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