Relationship between serum estradiol level, ultrasound follicle count, number of oocytes retrieved and their influence on IVF/ICSI treatment outcomes: a retrospective cross-sectional study

This retrospective cross-sectional study investigates determinants on follicular development, oocyte retrieval and pregnancy outcome. It assessed the clinical practicability of monitoring parameters in relation to predict a successful treatment. Analysis of serum-estradiol (E2), sonographic follicle count, number of oocytes and optimizable parameters have therefore been carried out based on patient files from the IVF outpatient clinic at the Department of Gynecology, Obstetrics and Reproductive Medicine, Homburg/Saar, Germany. Equidirectional connection occurred between serum-E2, sonographic follicle count and number of oocytes (p < 0.001). There was no significant difference between sonographic and punctured follicle count (p = 0.428), but between sonographic/punctured follicle count and number of oocytes obtained (p < 0.01). Increasing endometrial thickness was associated with increasing serum-E2 (p = 0.003) and number of oocytes (p < 0.001), but not with the follicle count (p > 0.05). Additionally, age was inversely associated with sonographic follicle count and number of oocytes (p < 0.001) but not with E2 (p > 0.05). BMI, nicotine and stimulation protocol had no association with the observed parameters (p > 0.05). Mean differences in follicle numbers can be used for predicting expectable numbers of oocytes. Due to comparable numbers of follicles visualized on the day of ovulation induction and the number of follicles punctured, more emphasis should be placed in optimizing oocyte retrieval procedures.