Administration of progestogens to hasten pituitary desensitization after the use of gonadotropin-releasing hormone agonist in in vitro fertilization--a prospective randomized study

Abstract

Objective: To assess the effect of administration of adjuvant IM progestogen to patients undergoing IVF who were not pituitary desensitized after 14 days of GnRH agonist (GnRH-a) administration.

Design: Prospective randomized study.

Setting: A tertiary referral center for assisted conception.

Patients: Forty-nine patients undergoing 51 IVF treatment cycles.

Intervention: Patients in whom the endometrial thickness was > 5 mm or who had an ovarian cyst > 15 mm after 14 days of GnRH-a administration were recruited if the serum E2 concentration was > 27.24 pg/mL (> 100 pmol/L). Patients in group 1 (n = 22) received a single IM injection of 100 mg P whereas patients in group 2 (n = 29) did not. Patients in both groups continued to receive SC GnRH-a 500 micrograms/d and had serum E2 levels measured every 3 days until the concentrations were < or = 100 pmol/L.

Main outcome measures: The number of days of GnRH-a administration from recruitment until serum E2 concentration measured < or = 100 pmol/L, number of cycles with withdrawal bleeding, number of days from recruitment to withdrawal bleeding, total dose of hMG used, number of follicles > 14 mm, number of oocytes, number of embryos, and pregnancy rates per cycle commenced and per ET.

Results: There were no significant differences in all the above parameters except in the mean number of days from recruitment to onset of withdrawal bleeding, which were 5.33 +/- 0.7 (mean +/- SEM) and 8.62 +/- 1.26 days in groups 1 and 2, respectively. The pregnancy rate per ET was higher in group 1 (38.88%) when compared with group 2 (19.04%). However, this difference was not statistically significant.

Conclusions: Adjuvant administration of a single IM injection of progestogen hastens the onset of withdrawal bleeding in patients who are not pituitary desensitized after 2 weeks of administration of SC GnRH-a. It does not appear to affect the length of time the serum E2 concentrations take to reach basal levels or to alter the ovarian responsiveness to exogenous gonadotropins.