Results of in vitro sperm penetration tests in cervical mucus in the normal cycle and in mucus under the influence of the contraceptive pill.

Women who are either menstruating normally or taking a combined or sequential preparation for hormonal contraception were examined at intervals of 2 days with reference to the day of the cycle. The parameter studied was the in-vitro penetrability of the cervical mucus for sperms. Whilst the combined preparation completely blocked the cervical canal for the spermatozoa, the distance travelled by the spermatozoa under the influence of the sequential preparation was approximately the same as in the normal cycle. This study of the depth of penetration of the spermatozoa in relation to the hormonal situation was prompted not by contraceptive but rather by epidemiological considerations of cervical carcinoma.