Related Experiment Video
Updated: Oct 3, 2026
Fertility Preservation Through Oocyte Vitrification: Clinical and Laboratory Perspectives
Published on: September 16, 2021
[A prospective, randomized controlled study comparing the effects of gonadotropin-releasing hormone agonist long and
1Institute of Reproductive and Genetics, Chongqing Obstetrics and Gynecology Hospital, Changqing 400013, China.
Objective:
To compare the effects of gonadotropin-releasing hormone agonist (GnRH-a) long and short protocols as part of in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) treatment.
Methods:
One hundred and nine infertile couples accepted a prospective, randomized comparative study for IVF or ICSI treatment were divided into GnRH-a long protocol group (55 cases) and GnRH-a short protocol group (54 cases). GnRH-a long protocol group: GnRH-a was taken by nasal spray 0.9 mg/day starting on day 21 of the previous menstrual cycle. Once the patient was down regulated, gonadotropin (Gn) injection was started. GnRH-a short protocol group: GnRH-a was taken by nasal spray 0.45 mg/day starting on day 2 of the menstrual cycle, and Gn was started on the same day. Two groups had human chorionic gonadotrophin (hCG) administered when the leading follicle was at least 18 mm in diameter. Oocytes were retrieved 36 hours after hCG administration guided by transvaginal ultrasounography. IVF/ICSI were performed as routine.
Results:
Serum follicle stimulating hormone and luteinizing hormone (LH) levels on the day of starting Gn were lower in the long protocol group comparing with the short protocol group [(4.4 +/- 1.2) IU/L Vs (6.3 +/- 1.7) IU/L, (2.7 +/- 1.5) IU/L Vs (4.4 +/- 2.8) IU/L, P < 0.01 respectively]. The levels of serum estradiol (E2), LH and E2 per oocyte on the day of hCG injection were lower in the long protocol group comparing with the short protocol group [(7,119 +/- 3,584) pmol/L Vs (9,523 +/- 3,587) pmol/L, (1.0 +/- 1.0) IU/L Vs (4.0 +/- 3.4) IU/L, (610 +/- 315) pmol/L Vs (935 +/- 450) pmol/L, P < 0.01 respectively]. Patients treated with short protocol were stimulated for a shorter period, required fewer Gn ampoules than the long protocol group [(10.1 +/- 1.5) d Vs (11.1 +/- 1.2) d, (23.4 +/- 8.7) Amps Vs (28.0 +/- 8.6) Amps, P < 0.01 respectly]. There are no statistically differences between the two groups in the numbers of oocytes retrieved, metaphase of second meiosis oocytes, fertilized oocytes, cleaved embryos, high quality embryos and pregnancy rates.
Conclusions:
The GnRH-a long and short protocols have equal effects on controlled ovarian hyperstimulation for in vitro fertilization. Patients who received GnRH-a short protocol required fewer ampoules of gonadotrpins and shorter period of treatment than those who received the GnRH-a long protocol.
