O-25: Serum Stem-Cell-Factor Assay in Elderly Poor Responder Patients Undergoing IVF: A New Biomarker to Customize Follicle Aspiration Cycle by Cycle.
Since the success rate in older poor-responder (POR) infertile women is expected to be extremely low irrespective of the treatment protocol, clinicians continue the search for biomarkers which may predict cases in which proceeding with follicle aspiration may be appropriate. Experimental studies on murine model suggest that SCF(Stem- Cell-Factor) produced by ovarian cumulus granulosa cell is a critical factor involved in the promotion of follicular growth and development of oocytes. In humans, SCF produced during follicular phase may reflect a successful stimulation and oocyte maturation, and so, it may be a predictor of IVF(invitro- fertilization) outcome. The aim of our research project is to understand if in POR infertile women undergoing IVF, the serum SCF (s-SCF) concentrations may correlate to intraintra- follicular SCF (f-SCF) concentrations according to different COH (controlled-ovarian-hyperstimulation) protocols. Moreover we evaluate if s-SCF concentrations before ovulation induction may represent a new tool to establish whether or not to perform follicle aspiration in elderly POR patients undergoing IVF.
Materials and methods
We recruited 37 elderly (43-50 years old) infertile women scheduled for their first fresh nondonor IVF treatment. All eligible patients underwent COH with standard long-protocol (rFSH starting dose 300IU) and, in the event of treatment failure (35 patients), repeat a cycle with LH-protocol (300 IU rFSH+150 IU rLH) within 6 months from the first treatment. When at least 3 follicles exceeded 16mm in diameter we administered rhCG for ovulation induction. Oocyte retrieval took place 35 hours after hCG administration. When obtained, 1 or 2 embryos were transferred 3 days after pick-up. From 144 samples collected at pick-up day, s-SCF and f-SCF levels were measured by ELISA-Kit to evaluate whether different protocols of COH may be associated with different levels of f-SCF and s-SCF, whether a correlation exists between f-SCF and s-SCF and whether a cut off value of s-SCF at ovulation induction might be associated with number and quality of oocytes and embryos obtained.
No differences were observed between the two protocols in terms of both f-SCF and s-SCF levels. The comparison between f-SCF and s-SCF levels showed a strong linear correlation (P<0.001). The comparison between s-SCF levels and clinical outcomes showed a statistically significant correlation between both the number of MII oocytes retrieved (P<0.001) and embryos obtained after fertilization (P<0.001). Cases with at least 3 MII oocytes showed s-SCF values >800 pg/mL, 2 MII oocytes >600 pg/mL and 1 MII oocytes >400 pg/mL. In 100% of cases with s-SCF <400 pg/mL no MII oocytes were recovered. All 5 pregnancies occurred in patients with s-SCF values >1000 pg/mL.
S-SCF, strongly correlating with f-SCF, demonstrated a good accuracy in predicting both cycles in which no oocytes and cycles in which at least one, two or three oocytes will be collected.