OVULATION

EXAMINATION OF THE CERVICAL MUCUS DURING THE MONTHLY CYCLE (FERNING)

Although the basal body temperature chart is the best single method of determining when ovulation occurs, it should be double-checked with another extremely simple method, the examination of the cervical mucus on various days of the cycle. During the earliest phase of the cycle, the cervix is closed and very little cervical mucus is produced. However, beginning around day nine or ten, under the influence of estrogen produced by the developing follicle, the production of the cervical mucus begins to increase and the cervix begins to open slightly. When follicular production of estrogen has reached its maximum, usually around 13^th or 14^th day in a normal cycle, the cervix is gaping open and one can actually see into it because the optically clear copious, watery cervical mucus is flowing out.

At this time, one or two days prior to ovulation, the cervical mucus is most receptive to invasion by sperm and the cervix is wide open in anticipation of their entrance. The physician can actually grasp a sample of this cervical mucus with a small clamp, and spread it out several inches. It will not break. It has the perfect, clear, copious, elastic consistency required for the sperm to launch a successful invasion.

Then when the woman ovulates and the progesterone is produced, the entrance to the cervix will dramatically close and the production of the cervical mucus will come almost to a standstill. What mucus is left will be sticky and tacky and will have lost its optical clarity. At this point sperm would have no chance of invading the mucus. If the physician sees a so-called "preovulatory" cervix (with a gaping opening and optically clear, abundant mucus) on day fourteen, if the temperature goes up the next morning and if the cervical opening never closes until after menstruation, this indicates that she is not ovulating.