Fertile cervical mucus generally refers to the mucus produced by the female cervix during or directly before ovulation. During this time, mucus may become more accommodating to any sperm which may enter to vaginal canal in order to increase the chances of conception. For many women, there is a marked change in the consistency and color of their cervical discharge during this period.
The look and feel of fertile cervical mucus may vary slightly for each woman, but it generally becomes heavier during the time of ovulation and is more slippery, stretchy, and clear. It is often compared to the consistency of egg whites, and it is designed this way to help aid sperm up the birth canal. The vagina is naturally acidic, which can kill sperm, while the mucus is alkaline to protect them in order to make pregnancy more likely.
At other times of the month, cervical discharge changes to a less fertile state. During the weeks leading up to the menstrual period, it may cease altogether or be produced in a much smaller quantity. The color may also go from the clear appearance of fertile cervical mucus, to a white or off-white color. It may also become less slippery over time and it may be thicker.
By learning to recognize what fertile cervical mucus looks like, women may be able to track ovulation to either become pregnant or prevent a pregnancy. This requires several months of paying close attention to the changes which take place in mucus consistency throughout each month so that the discharge which accompanies ovulation becomes clearly recognizable. It should be noted that most health care professionals do not consider this a suitable option for birth control when used alone, although some studies have shown it to be highly effective when used correctly in women with normal monthly cycles.
Other changes take place during the month in the cervix. For instance, during ovulation when fertile cervical mucus is at its highest, the cervix also moves higher into the uterus and opens slightly to make the way for sperm to enter. After ovulation is over, it descends lower into the vagina and closes again until the menstrual period begins.
While these changes are typical, each woman is an individual and may experience slightly different changes in her body during her menstrual cycle. Some may have more discharge than others and the color and texture of her fertile cervical mucus may not be exactly as described in a textbook. That said, discharge that is yellow, green, foamy, clumpy, or accompanied by an odor should be reported to a doctor as this could indicate a vaginal infection or sexually transmitted disease.