Objective: To study the effect of peritoneal (PF) and follicular fluids (FF from the same woman) as well as of given volumetric combinations thereof on sperm motility and acrosomal reactivity.
Design: Prospective. Peritoneal fluid and FF were incubated separately or in given volumetric combinations (PF/FF = 100/0, 75/25, 50/50, 25/75, 0/100; vol/vol) with swim-up sperm suspensions.
Setting: In vitro fertilization and general infertility clinic and laboratories.
Patients, participants: Women participants of the gamete intrafallopian transfer program (motility study, n = 20; acrosomal reaction study, n = 14). Sperm donors of the artificial insemination program and men with given sperm parameters.
Interventions: Hormonal stimulation. Laparoscopy.
Main outcome measures: Progressive velocity and percentage of motile gametes measured with multiple-exposure photography. Acrosomal reactivity measured by an immunofluorescent technique.
Results: Follicular fluid always influenced progressive motility and also sustained the number of motile gametes, as function of time, better than PF or the PF/FF mixtures (P less than 0.05). The acrosomal reactivity of sperm incubated in the various PF/FF combinations was low; after 5 hours only the FF-sperm suspensions showed a significant enhancement of acrosomally reacted gametes.
Conclusion: At ovulation, FF transmit positive (motility- and acrosomal reactivity-enhancing) signals to sperm, whereas PF may transmit positive, neutral, or negative signals (noise signals). The volumetric combination of FF and PF in the tubal environment, which may differ from cycle to cycle and from woman to woman, could therefore result in synergic (or antagonistic) effects on the sperm fertility potential.