CYCLIC PENETRABILITY OF HUMAN CERVICAL MUCUS TO SPERMATOZOA IN VITRO

Abstract

A new method for studying penetration of cervical mucus by spermatozoa in vitro is described involving the use of microtubes and barrier marker bubble. This method is considered better than slide cover glass preparations because it prevents undiscoverable mechanical mixing of mucus and semen and drying of the preparation and because it can be used to study penetration quantitatively and to study the longevity of the spermatozoa in the mucus. Results by this method confirmed the in vivo and in vitro findings of Seguy and Vimeux namely that there is a cyclic production of a glairy translucent cervicalmucus at about midcycle which renders the cervix temporarily penetrable by spermatozoa. Roughly the spread of this phase was in this study from days 9-19 but for any given cycle the period may actually be approximately 4 days. Indications are that menstrual discharge is penetrable by spermatozoa but the mucus of the period between menstruation and midcycle is relatively impenetrable and that of the phase between midcycle and subsequent menstruation is impenetrable. Correlated with the midcycle peak in penetrability is the peak in freedom from leucocytes the peak in pH (except during the menstrual flow) the peak in amount of mucus secreted and the height of conditions favoring greatest longevity of spermatozoa in the mucus. It may well be that the actual viscosity of the mucus encountered by sperm is lowest at midcycle. It is suggested that both low pH and large number of cells in the secretory phase may be caused at least in part by the low rate of mucus secretion. An investigation of the cervical mucus over the cycle by the in vitro method is suggested in cases of otherwise unexplained infertility. A field of usefulness for artificial insemination may be developed in cases due to persistent impenetrable cervical mucus. (authors modified)