2009년 미국불임학회(ASRM) P-279 Extended duration of gonadotropin releasing hormone(GNRH) antagonist was associated with a significant decrease in pregnancy rate. (GnRH 길항제를 장기간 사용하는 것은 임신율 감소와 중요한 상관관계가 있다.)

S. G. Kim1, S. J. Kim1, I. H. Park1, M. H. Kim2, Y. Y.Kim2, K. H. Lee1.
1 Infertility Lab., mamapapa & Baby Obstetrics and Gynecology Clinic, ULSAN, Republic of Korea
2 Ellemedi Obstetrics and Gynecology Clinic, Changwon, Republic of Korea

OBJECTIVE

In GnRH antagonist flexible protocol, there are individual variation in start timing and duration of GnRH antagonist. The objective of this study is to confirm whether the duration of GnRH antagonist could influence on pregnancy rates.

DESIGN

Retrospective analysis

MATERIALS AND METHODS

GnRH antagonists were began using a flexible start based on lead follicle size of 12 -14 mm. Patients were divided into four groups according to duration of GnRH antagonist. Group A (n=125): 4days, B (n=218): 5days, C (n=96): 6days, D (n=25): 7days. Duration of GnRH antagonist use in shorter than 3days and in longer than 8days were excluded, because of small sample size. IVF outcomes were statistically analyzed by t test. P value <0.05 was considered statistically significant.

RESULTS

The 464 embryo transfers performed during the study period resulted in 215 pregnancies (46.3%). The mean±SD age of the patients (Group A: 34.3±4.3; B: 34.2±4.0; C: 34.6±4.6; D: 34.7±4.3) and the number of embryos transferred (3.5±1.1; 3.5±1.2; 3.8±1.1; 3.6±1.5) were comparable in four group. However, pregnancy rate, the number of retrieved oocytes (14.6±10.6; 11.8±7.7; 12.2±6.6; 9.4±7.1) shows decreasing tendency as duration GnRH antagonist prolonged. Group A, B and C was no significant difference between regimens for pregnancy rate. Moreover, pregnancy rate showed a significant decrease for 7days (32.0%) of GnRH antagonist dosing when compared to either 4days (52.8%), 5days (45.0%) or 6days (44.8%), respectively (p <0.05).

CONCLUSION

Extended duration of GnRH antagonist in flexible protocol was associated with a significant decrease in pregnancy rate. Extended duration of GnRH antagonist may be a predictor of risk for poor cycle outcome. Especially, pregnancy rate in 7days duration of GnRH antagonist was significant decrease. GnRH antagonists can be administered just before the expected LH surge and need to be administered only for a few days. So, shorter period in administration of GnRH antagonist is able to predict a good result in pregnancy rate.