The sequential effects of human cervical mucus, oviductal fluid, and follicular fluid on sperm function.

OBJECTIVE

To compare the sequential effects of human cervical mucus (CM), oviductal fluid, and follicular fluid (FF) on sperm motility, hyperactivation, and the acrosome reaction during 9 hours of incubation in vitro.

DESIGN

Spermatozoa from a fertile donor were allowed to penetrate human CM in vitro and then were recovered and incubated in either 30% human oviductal fluid or a simple salt solution for 3 hours before challenge with 20% FF. Thus, the sequential effects of the fluids collected from the female reproductive tract on sperm hyperactivation and acrosome reaction were examined.

SETTING

The donor insemination program at the University Clinic within the Jessop Hospital for Women, Sheffield, United Kingdom.

PATIENTS

All donors used in this study were involved in the donor insemination program.

MAIN OUTCOME MEASURES

Sperm motility, hyperactivation, and percentage of acrosome-reacted spermatozoa were measured.

RESULTS

This study used an in vitro technique to mimic sperm transport in vivo. Spermatozoa sequentially incubated with female reproductive tract secretions in vitro showed a maintenance in the level of FF-induced hyperactivated motility and a decreased response to the FF-induced acrosome reaction when compared with sperm challenged with FF in the absence of prior incubation with human oviductal fluid.

CONCLUSION

It is suggested that human oviductal fluid may serve to delay the FF-induced acrosome reaction.