Abstract
BACKGROUND: Controlled ovarian hyperstimulation (COH) for in vitro fertilization (IVF) is essential in improving the pregnancy rate, but supraphysiologic levels of estradiol (E2), which are attained during COH and which affect the outcome of IVF, have remained unclear. The aim of this study was to evaluate the association of E2 levels on the day of hCG with embryo quality and pregnancy rates in long protocol in IVF. MATERIALS AND METHODS: We retrospectively reviewed 128 IVF cycles. All the patients were stimulated with long protocol. The patients were categorized into three groups according to the serum E2 levels on hCG administration day (group 1; <1500 pg/ml, group 2; 1500-3500 pg/ml, group 3; >3500 pg/ml). RESULTS: Of the 128 cycles, 23 (18 %) cycles resulted in pregnancy. There were no statistically significant differences between mean age, duration of infertility, BMI and FSH on cycle day 3 in three groups. The number of the retrieved oocytes, the number of obtained embryos, the number of transferred embryos, and pregnancy rates were gradually increased from group 1 to 3 as estradiol levels increased, and these values were statistically significant (P < 0.05). In addition, the correlation between age and IVF outcome was found. Mean age in patients with positive pregnancy test was lower than that in patients with negative pregnancy test, and this difference was statistically significant. CONCLUSION: This study shows that there is a positive association between estradiol level on hCG administration day and pregnancy rates in IVF cycles.