THE FERN REACTION OF CERVICAL MUCUS.

The fern reaction of endocervical mucus was tested in 100 non-pregnant and 200 pregnant women with a view to establishing the relationship of this fern pattern to normal ovarian cyclical changes and normal pregnancy. The fern appeared at day 7-9 of the cycle and disappeared at day 18-20. Twenty-eight of 100 pregnancies before 10 weeks yielded positive fern reactions; two of 100 pregnancies after 10 weeks yielded positive fern reactions. In the presence of a positive fern reaction, the administration of 10 mg. of norethynodrel (Enovid) daily for seven days led to prompt withdrawal bleeding in the absence of pregnancy. With a negative fern reaction, a spontaneous period ensues within 12 days in the absence of pregnancy. Two hundred women were tested for early pregnancy on this premise; in 198, a correct diagnosis was obtained.