Effects of invivo exposure to eggs with sperm-immobilizing antibodies in follicular fluid on subsequent fertilization and embryo development invitro.

Abstract

Aims: It has been shown that supplementation of patients' sera that contains sperm-immobilizing antibodies results in failure of fertilization and embryo development invitro. The present study was carried out to investigate if exposing retrieved eggs to a high number of sperm-immobilizing antibodies in the follicular fluid (FF) invivo affected subsequent fertilization and embryo development invitro, even if they were washed with an antibody-free culture medium. Methods: Patients' sera and their FF were collected in 15 invitro fertilization-embryo transfer (IVF-ET) or intracytoplasmic sperm injection-embryo transfer (ICSI-ET) treatment cycles from 11 infertile women with sperm-immobilizing antibodies in their sera. Quantitative sperm-immobilizing antibody titers (SI50 titers) in the sera and FF were evaluated. The fertilization rate, good-quality embryo rate and implantation rate by IVF-ET were compared between infertile patients having higher (10≤) SI50 titers and lower (<10) SI50 titers in their FF. Results: There was a significant correlation in the SI50 titers between the patients' sera and their FF (P<0.0001). After thoroughly washing the collected eggs in culture medium without the patient's serum before IVF, there was no difference in the fertilization rate in the patients with high (10≤) and low (<10) SI50 titers in their FF (P=0.62). However, the good-quality embryo rate in the patients with a high SI50 titer was significantly lower than patients with a low antibody titer (P < 0.05). There was no significant difference in the implantation rate between the two groups (P=0.33). Conclusions: Similar amounts of sperm-immobilizing antibodies existed in the patients' FF and in their sera. ICSI did not seem to be necessary in patients having the antibodies if their sera were not supplemented in the culture media. Even with careful manipulation of eggs, it might be suggested that the harmful effects of sperm-immobilizing antibodies on embryo development cannot be completely avoided, especially in patients with high SI50 titers in the FF. (Reprod Med Biol 2006; 5: 137-143).