Interleukin 6 in follicular fluid reduces embryo fragmentation and improves the clinical pregnancy rate.

Purpose: The aim of this study was to evaluate the role of interleukin 6 in embryo development in the in vitro fertilization cycles.

Methods: This was a retrospective cohort study. One hundred and three women undergoing in vitro fertilization and embryo transfer due to a tubal factor were included in the study. The follicular fluid IL-6 levels on oocyte retrieval day from each patient were determined by ELISA. The relationships between follicular fluid IL-6 levels and IVF cycle parameters were investigated.

Results: The levels of follicular fluid IL-6 were not affected by the use of drugs for superovulation or by estrogen. In addition, follicular fluid IL-6 levels did not affect the number of oocytes retrieved or the MII oocyte rate. High levels of follicular fluid IL-6 correlated with a significant increase in the rates of clinical pregnancy. Follicular fluid IL-6 levels did not affect the cell number or the blastomere symmetry of day 3 embryos, but it did significantly reduce the embryo fragmentation rate.

Conclusions: High levels of follicular fluid IL-6 improved the rates of clinical pregnancy and reduce embryo fragmentation.