Follicular fluid estradiol is an improved predictor of fertilization/intracytoplasmic sperm injection and embryo transfer outcomes.

The present study is a clinical trial analyzing follicular fluid. The current study aimed to assess whether a correlation exists among estradiol (E2), anti-Mullerian hormone (AMH) and prokineticin 1 (PROK1) levels in the follicular fluid. A total of 81 infertile patients (53 with primary infertility and 28 with secondary infertility) who received routine fertilization (IVF) and embryo transfer (ET) or intracytoplasmic sperm injection at Yuhuangding Hospital (Yantai, China) were included in the present study. On the day of egg retrieval, follicular puncture and follicular fluid extraction were performed on patients using double lumen needles under the guidance of a vaginal ultrasound. In 77 cases, follicular fluid was collected from the follicle with the largest diameter. A total of 53 cases underwent ET and subsequent pregnancy outcomes were traced. Concentrations of E2, AMH and PROK1 in the single follicular fluid specimens were determined. The concentration of E2 in follicular fluid from the largest follicles in absolute pregnancy group was significantly lower than that in absolute non-pregnancy group. The concentrations of PROK1 and AMH in follicular fluid from the largest follicles in absolute pregnancy group were not significantly different from those in absolute non-pregnancy group. The concentration of E2 was associated with the dosage of gonadotropin, but was not associated with age, AMH and PROK1 levels in follicular fluid, fertilization rate or number of usable blastocysts. The area under curve revealed that E2 level in the follicular fluid exhibited a low predictive value for pregnancy outcome. The present study demonstrated that E2 level is a better predictor for the outcome of IVF-ET than AMH or PROK1 levels in the follicular fluid.