The relationship between endometrial thickness and pregnancy rates in GnRH antagonist down-regulated ICSI cycles

Objective. To investigate the effects of endometrial thickness measurements and serum hormone levels on the outcomes of GnRH antagonist down-regulated ICSI cycles. Study design. Forty consecutive infertile women undergoing controlled ovarian hyperstimulation with recombinant FSH and GnRH antagonists for ICSI were enrolled in this study. All patient's age, day 3 FSH, antral follicle count (AFC), serum E2 levels on day 3, E2 on stimulation day 5, E2 on day of hCG administration, endometrial thickness on the baseline (ETMBaseline), on day 5 of stimulation (ETMDay 5), on day of hCG administration (ETMhCG) and cycle outcomes were recorded. The outcomes of pregnant and nonpregnant women were compared. Results. Women's age was 33.6 +/- 4.9. Overall pregnancy rate was 45% (n = 18), clinical pregnancy rate was 27.5% (n = 11) and ongoing pregnancy rate was 20% (n = 8). In pregnant women, baseline AFC was significantly higher compared with nonpregnant women (p = 0.01). There was no significant correlation between ETMhCG and E2 level on the day of hCG, number of retrieved oocytes or patients' age. Conclusion. For achieving pregnancy, endometrial thickness on the day of hCG is not a determining parameter, and the only significant determinent is AFC in GnRH antagonist down-regulated ICSI cycles.