[Results of in vitro sperm penetration tests in cervical mucus under takings of the sequential oral contraceptive ovanon and sequilar (author's transl)].

The in vitro penetrability of cervical mucus by sperm was investigated in women who were taking Ovanon or Sequilar. Measurements were made under constant experimental conditions on every day of the cycle. The depth of penetration differed strikingly between women with normal menstrual cycles and women taking the sequential hormonal contraceptives. The penetration depth was substantially less when Sequilar or Ovanon was used. The Sequilar induced cervical sperm barrier during the entire cycle was almost as strong as that observed when combined preparations are used. During the proliferative phase of the cycle the penetration depth allowed by Ovanon was less than that observed during normal cycles but greater than that seen with Sequilar. During the secretion phase no appreciable differences in the penetrability of cervical mucus between the two contraceptives was observed. The hypothetical relationship between these data and the problem of cervical carcinoma was described.