The leukocytic reaction of the human uterine cervix to spermatozoa.

Cervical smears were taken before, and at intervals after, artificial insemination and scored for the ratio of leukocytes to squamous cells. Most women showed a significant rise in this ratio after insemination with whole fresh or frozen/thawed semen, but this was not seen when fresh or frozen sperm-free seminal plasma was used. Some women had received spermatozoa naturally less than 24 hours before our tests, and most showed some leukocytosis before insemination; even these women showed further response to artificial insemination with spermatozoa. It is concluded that women, like rabbits, normally respond by leukocytosis to cervical deposition of spermatozoa. The primary function of the leukocytes may be sperm selection by phagocytosis or the "mopping up" of introduced bacteria. Some of the patients became pregnant at the monitored cycle; so it is very clear that this is a physiologic response of the cervix, not a pathologic leukocytic reaction.