Dose of GnRH agonist (nafarelin acetate) affects intrafollicular PAPP-A expression in controlled ovarian hyperstimulation cycle

Objective: To determine the effect of dose of GnRH agonist on the follicular environment in controlled ovarian hyperstimulation (COH) cycles. Study design: Twenty-eight IVF patients with normal ovarian function were divided into three groups: group I received GnRHa (nafarelin acetate/Synarel) intranasally at 200μg daily, group II received 400μg daily until hCG injection, and group III was given 400μg daily before the initiation of ovarian stimulation, then 200μg daily before the day of hCG injection. Serum estradiol, progesterone, and leptin levels were measured on the day of hCG injection. After aspiration, expression of pregnancy-associated α-plasma protein (PAPP)-A in the follicular fluid of dominant follicles (>20mm) was determined by Western blot analysis. Results: No significant difference was noted in serum estradiol, progesterone, and leptin levels. But intrafollicular PAPP-A expression was significantly higher in group II compared to other groups (P<0.05). Conclusion: The dose of GnRHa may have an impact on the intrafollicular environment of dominant follicles in COH cycles.