Association between estradiol levels and clinical outcomes of IVF cycles with single blastocyst embryo transfer

Objective: To determine the correlation of different serum estradiol levels on the trigger day with the clinical and laboratory outcomes of in-vitro fertilization (IVF) cycles comprising a single fresh top-quality blastocyst transfer. Methods: This was a retrospective observational study performed in Morula IVF Clinic Jakarta. Five hundred forty-two women were recruited and grouped according to their serum estradiol levels on the trigger day of follicular maturation as follows: <2 000 pg/mL, 2 000-2 999 pg/mL, 3 000-3 999 pg/mL, and >= 4 000 pg/mL. Clinical pregnancy and miscarriage rates were evaluated as the primary outcomes and embryology laboratory results as the secondary outcomes which consisted of the number of retrieved, mature, and fertilized oocytes, the total sum of derived embryos, and top-quality embryos at cleavage and blastocyst stage. Results: Clinical pregnancy and miscarriage rates did not differ among the groups (P>0.05). Nonetheless, the study demonstrated a positive correlation of the serum estradiol levels with the overall laboratory outcomes including the number of retrieved, mature, and fertilized oocytes, the total sum of derived embryos, and top-quality embryos at cleavage and blastocyst stage (P<0.001). The subject group with estradiol level of >= 4 000 pg/mL was superior to the other groups in its respective median number of retrieved, mature, fertilized oocytes, total derived embryos, and top-quality cleavage- and blastocyst-stage embryos. Conclusions: Although an apparent positive correlation is observed between estradiol levels and laboratory outcomes, serum estradiol level on hCG trigger day is not associated with the clinical outcomes of IVF.