Serum steroids concentration might be used for monitoring the growth of follicles in friendly fertilization.

Steroid levels have been used as the predictive parameters for oocyte maturation and embryo development. In the present study, estradiol and progesterone concentrations in the follicular fluid and serum were evaluated in conventional fertilization (IVF; follicle stimulating hormone [FSH] and/or human menopausal gonadotropin [hMG] after pituitary desensitization) and friendly IVF (no stimulation, clomiphene citrate, small dose of FSH or hMG without pituitary desensitization). The purpose of the present study was to evaluate the differences in steroid distribution between conventional and friendly IVF. Concentrations of estradiol, progesterone, FSH, and luteinizing hormone (LH) in serum and follicular fluid were determined in conventional and friendly IVF protocols by an enzyme-linked immunosorbent assay kit. Correlations between follicular fluid and serum steroid concentrations in these different protocols, and between pregnant cycles and steroid concentrations were evaluated. Two hundred and thirty-four samples of follicular fluid from 74 IVF patients were analyzed. In conventional IVF, there was no relationship in steroid levels in between follicular fluid and serum steroids, whereas serum steroid concentrations correlated with the number of developing follicles. There was a relationship between the serum and follicular fluid estradiol levels ( = 0.467,  < 0.0001) as well as progesterone levels ( = 0.227,  = 0.0488) from friendly IVF patients. Serum steroid concentrations were mainly associated with the number of developing follicles. In the cases of friendly IVF, which had a small number of developing follicles, serum steroids might be used to monitor follicular fluid steroid concentrations. (Reprod Med Biol 2006; : 277-282).