The expression of matrix metalloproteinase-9 in human follicular fluid is associated with in vitro fertilisation pregnancy

Objective: To investigate the role of matrix metalloproteinase-9 (MMP-9) in the pre-ovulatory follicular fluid and culture media during in vitro fertilisation (IVF) cycle and to develop the zymographic pre-diagnosis marker for successful implantation and pregnancy in human IVF. Design: Controlled clinical study. Setting: IVF Laboratory, Women's Hospital Infertility Clinic and Dongguk University, Korea. Sample: Women undergoing in vitro fertilisation treatment. Methods: Experiments were designed for controlled clinical study with women undergoing IVF treatment. MMP-9 expressions in follicular fluid and culture media samples that had been, collected during transvaginal oocyte retrieval were measured using zymography. MMP-9 activities and expressions were strongly correlated to a higher rate of fertilisation and pregnancy. Main outcome measures: Fertilisation rates and ultrasonic evidence of intrauterine pregnancy by four weeks after embryo transfer. Result: MMP-9 activity was significantly higher in the pregnant group than in the non-pregnant group (P < 0.01.). In contrast, MMP-2 activity was present in the follicular fluid and culture media of all women, and no difference in its expressions was found between the pregnant and non-pregnant groups. No correlation was found between the MMP-9 expression in follicular fluid and culture media and the fertilisation rates. Conclusion: The expression of MMP-9 in the follicular fluid and culture media is a prerequisite for successful pregnancy in IVF cycle. The zymography of MMP-9 activity in follicular fluids of human and culture media was developed as a pre-diagnostic method and zymographic diagnosis marker for successful fertilisation, implantation and pregnancy in human IVF.