Cycle monitoring is a method used by OBGYNs and fertility specialists to map out a woman's monthly menstrual cycle, in order to determine when ovulation is most likely to occur. Every woman has what is known as a fertile window; the days leading up to and including ovulation. This is the phase of the menstrual cycle when a woman is most likely to get pregnant. Because every woman's cycle is different, with many women experiencing irregular periods which can make it harder to predict ovulation, cycle monitoring is useful for couples trying to conceive, either naturally or with the aid of IVI (Intravaginal insemination) or IVF (Invitro fertilization).

Ovulation and the Menstrual Cycle

A typical menstrual cycle is approximately 28 days, but varies from woman to woman. Ovulation is the monthly process where an egg is released for fertilization by the sperm, and it is the only point in the menstrual cycle when conception is possible. Healthy sperm generally remain viable for up to five days, which is factored into the fertile window when calculating a fertility chart and menstrual cycle for a woman actively trying to conceive.

Many women are unaware of their ovulation schedule, and many myths abound about the length and duration of the fertile window. Because menstrual cycles can vary greatly from one woman to the next, a consultation with an OBGYN can help women determine their ovulation schedule once they have decided they are ready to become pregnant.

Determining Ovulation and the Fertility Cycle

The first step in cycle monitoring is measuring the basal body temperature. Although the variations in temperature can be slight, and OBGYNs have found the effectiveness of basal body temperature measurements in predicting ovulation to be inconclusive, it is still considered a basic step in charting fertility. During ovulation, the body releases elevated levels of the hormone progesterone, which can cause slight fluctuations in temperature. During ovulation, the cervix produces elevated levels of mucus designed to help the sperm make its way to the egg for fertilization. Monitoring mucus levels can help to predict ovulation. The mucus becomes more elastic, clear (resembling the texture and consistency of egg whites) during the fertile window.

The range varies from woman to woman, but days 1-5 are the beginning of the cycle, when menstruation occurs. Days 6-9 are dry with no visible mucus. From days 10-12 the mucus is sticky and thicker than during the fertile window. At the end of the fertile window the mucus becomes thick and sticky again, followed by dryness until the cycle begins again the following month. Measuring the cycle for a few months can help to determine both the duration and ovulation dates for each woman.