Area under the curve of temporal estrogen and progesterone measurements during assisted reproductive technology: Which hormone is the main determinant of cycle outcome?

Aim: Is there any relationship between estrogen and progesterone concentrations during assisted reproductive technology (ART)? Which hormone is the main determinant of impaired endometrial receptivity?

Methods: This study was conducted from July to December 2016 at the in vitro Fertilization/Intracytoplasmic Sperm Injection unit at Zeynep Kamil Women and Children's Health Training and Research Hospital. A total of 289 women who underwent ART were prospectively screened and areas under the curve of temporal estrogen (AUCEM) and progesterone measurements (AUCPM) were calculated for each participant. Women were included if they had regular menstrual cycles, normal serum prolactin levels and had not received hormone treatment within three months. ART was indicated in all patients for unexplained infertility. Patients were divided into two groups: with (n = 90) and without (n = 199) embryo implantation. The relationship between the two AUCs and ART success was assessed in terms of embryo implantation and clinical pregnancy.

Results: Implantation was successful in 90 (31.1%) women, and a fetal heart rate was detected in 83 (28.7%) cases. There was a significant correlation between AUCEM and AUCPM (r = 0.525, P < 0.001). Multivariate regression analysis showed significant associations between failure of implantation, lack of clinical pregnancy and AUCEM (beta coefficient = 0.311, P < 0.001; beta coefficient = 0.297, P < 0.001, respectively) after adjusting for AUCPM.

Conclusion: Our data showed that the degree of endometrial estrogen exposure is the main factor functioning as a detrimental effect of ovarian stimulation on endometrial receptivity.