Sperm-immobilizing antibodies block capacitation in human spermatozoa.

Sperm-immobilizing antibodies block human fertilization by interfering with the acrosome reaction (AR). To clarify the mechanism of blockage of AR by sperm-immobilizing antibodies, the authors examined their effects on the increase of intracellular free Ca2+ concentration induced by follicular fluids (Ca2+ influx) in spermatozoa and on their capacitation. Sperm-immobilizing antibodies did not suppress Ca2+ influx induced by follicular fluid, but they inhibited capacitation of human spermatozoa. Namely delta%AR (%AR after addition of an AR inducer--%AR before treatment) induced by progesterone was significantly (p < .0001) lower when spermatozoa were incubated in human tubal fluid medium cotaining antibody-positive serum (1.2%), compared to that when incubated in control medium (19.2%). Furthermore, the proportion of both spermatozoa that became capacitated and ones that had become capacitated decreased significantly (p < .0001) after 2, 4, and 6 h of incubation in medium containing antisperm antibody-positive serum, compared to those of spermatozoa incubated in control medium. In conclusion, sperm-immobilizing antibodies may be closely related to their blockage of capacitation.

Avoidance of oocyte retrieval on the weekend through the use of scheduled ovarian hyperstimulation for in vitro fertilization and embryo transfer.

OBJECTIVE: To avoid oocyte retrieval for IVF-ET during the weekend, the scheduled method of ovarian hyperstimulation, in which oocyte retrieval is planned in advance for Monday through Wednesday, was evaluated. DESIGN: A retrospective study. SETTING: The IVF-ET unit of the Department of Obstetrics and Gynecology at Tokushima University Hospital. PATIENT(S): One hundred seventy-eight cycles in patients undergoing ovarian hyperstimulation for IVF-ET were stimulated according to the scheduled method of ovarian hyperstimulation (scheduled group). One hundred seventy-one cycles in patients of similar age and with comparable causes of infertility were stimulated according to the conventional method of ovarian hyperstimulation for IVF-ET (conventional group). INTERVENTION(S): In the scheduled method, under GnRH-a, the day of oocyte retrieval was determined in advance for IVF-ET. Ovarian stimulation with FSH and hMG was started 12 days before oocyte retrieval. MAIN OUTCOME MEASURE(S): The cancellation and clinical pregnancy rates (PRs), the days of oocyte retrieval, and other clinical parameters were evaluated in the two groups. RESULT(S): The cancellation rates in the scheduled and conventional groups were 9.6% and 4.7%, respectively. In about 75% of cycles in the scheduled group, oocyte retrieval was conducted on the scheduled day. When oocyte retrieval was scheduled for Monday through Wednesday, overtime work on the weekend could be avoided in 91% of the cycles without cancellation. The clinical PR was comparable between the two groups. CONCLUSION(S): The scheduled method of ovarian hyperstimulation for IVF-ET was useful for avoiding oocyte retrieval on the weekend.