The Menstrual Cycle As Fertility Marker

Swedish researchers have found that the length of a woman’s menstrual cycle can be used to calculate a woman’s fertility. Researcher Dr. Thomas Brodin and his colleagues, who hail from Malarsjukhuset, a hospital located in Eskilstuna, Sweden analyzed the successful outcomes of 6,271 in vitro fertilization (IVF) cycles and correlated them with the patients’ menstrual cycle lengths.

Shortening Cycles

The results of their work appeared in the journal Fertility and Sterility. The researchers discovered that with increasing age, there was a slight shortening in the length of the participants’ menstrual cycles. This shortening of the cycle runs along predictable lines with the length of the cycle losing an average of 2 days each year during a woman’s 20’s through her 40’s.

After the researchers factored in the age of the participants, it became obvious that cycle length had a direct link to the possibility of conception and birth. The research team observed that the chances for a successful delivery after undergoing IVF nearly doubled in women who had the longest cycles of over 34 days in comparison with older women whose cycles were shorter than 26 days.

Irregular Ovulation

A consulting obstetrician and gynecologist at University College Hospital (UCH), Ibadan, Oyo State, Dr. Kayode Afolabi, commented that changes in the menstrual cycle signify an abnormal cycle and/or a failure to ovulate. A shortened cycle is called oligomenorrhea. When there is oligomenorrhea, or in the case in which menstruation ceases for some months and then resumes, there is a suggestion that ovulation is not occurring on a regular basis. If a woman fails to ovulate, it is impossible for pregnancy to occur.

According to Afolabi, if the menstrual cycle is termed abnormal, this means that menstruation comes less or more often, become scanty or profuse, or ceases altogether. When periods become scanty, it tends to mean that the woman experiences a failure to ovulate.

Scanty periods often occur as a result of hormonal fluctuations. In some women, the level of prolactin rises and this causes a reduced menstrual flow. The ovaries will show the effects of the rising levels of this hormone and will stop producing the normal amount of eggs.

In other cases, other hormones are the culprit. Too much thyroid hormone, for instance, will cause a scanty or absent menstrual flow.

But there are other reasons for abnormal menstrual flow. There may be some type of blockage. Women who have experienced vaginal infections or have had a D & C may also begin to show abnormalities of the menstrual cycle.