Increase in transforming growth factor beta1 in ovarian follicular fluid following ovarian stimulation and in-vitro fertilization correlates to pregnancy.

We have analysed the content of the growth and differentiation regulating peptide, transforming growth factor beta1 (TGFbeta1), in follicular fluid from patients undergoing in-vitro fertilization (IVF), and correlated concentrations of TGFbeta1 with the outcome of the IVF treatment and the concentrations of 17beta oestradiol in serum at ovum retrieval. A total of 88 women with infertility of >3 years duration and age <38 years participated in the study. During IVF treatment, follicular fluid and matched serum samples were collected at ovum retrieval and analysed for TGFbeta1, oestradiol, progesterone, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) using radioimmunoassay and enzyme-linked immunosorbent assay. We found that the TGFbeta1 content in the follicular fluid at the time of oocyte retrieval correlated positively with subsequent pregnancy. In 29 women who became pregnant following IVF, follicular fluid TGFbeta1 values were significantly higher (P=0.005) than in 59 women where IVF was unsuccessful. In the pregnant group, TGFbeta1 values correlated positively with oestradiol at ovum retrieval. TGFbeta1 also correlated positively with the number of fertilized oocytes. TGFbeta1 may thus be important for successful human pre-embryo development, contribute to successful embryo implantation and development and may be necessary for the establishment of pregnancy.