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

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.