researchers had studied the phenomenon of ferning in cervical fluid when Papanicolau observed microscopic crystal formations in cervical fluid (mucus).
The crystallization of saliva
was studied in 1969 by Dr. Biel Cassals, a Spanish gynecologist. His presentation to the Barcelona Medical Board proved a relationship between hormonal changes during the female menstrual cycle and the crystallization of saliva, indicating ferning saliva is virtually identical in appearance to the arborization effect of cervical fluid.
The hormone estrogen links saliva patterns to a woman's
Both saliva and cervical mucus have shown these patterns.
As ovulation nears, estrogen increases and causes the body's sodium levels to rise, increasing the salinity of a woman's saliva. Near ovulation, the higher salt content
causes the dried saliva to form crystallization patterns, as seen under the microscope. Both saliva and cervical mucus have shown these patterns.
In 2009, the KNOWHEN® Advanced Saliva Ovulation Test was
cleared and registered by FDA.
U.S. clinical studies proved KNOWHEN® to be 98.9% accurate.
Clinical studies were performed at Manhattan Fertility Center by Dr. Hugh Melnick. Dr. Melnick's studies found a close correlation between actual ovulation as determined by sonographic examination of the ovaries and the presence of a ferning pattern in saliva as determined by the KNOWHEN® Ovulation Predictor System.