Menstrual Cycles & Ovulation

Understanding what happens during a woman’s menstrual cycle is essential toward increasing your chances of conception. By noting the hormonal changes that occur during a woman’s cycle, couples can predict on which days she will be most fertile. Even when you aren’t trying to conceive, by understanding your own cycles, you can more accurately gauge your health and keep track of any changes or aberrations that should be brought to the attention of your physician.

Unlike a man, who produces new sperm on a regular basis, when a woman is born she has all the eggs, or ova, she will ever have – between 1 million and 2 million. By puberty, a natural attrition process causes the number of eggs to decrease to about 400,000 to 500,000. A woman’s eggs are stored in her ovaries, in structures called follicles.

The menstrual cycle is the process a woman’s body goes through to prepare for pregnancy. During menstruation, the body releases hormones that can make pregnancy possible, and menstruation itself rids the body of the uterine lining when conception does not occur. Ovulation also occurs during the menstrual cycle, as an egg is released by the ovaries in preparation for pregnancy.

Menstruation involves more than the reproductive organs. In fact, the cycle begins with the brain. During the first half of the menstrual cycle, the a gland called the hypothalamus, located in the brain, instructs the pituitary gland, also located in the brain, to release hormones that help an egg to mature. These follicles respond by releasing the hormone estrogen. As a result, the lining of the uterus becomes thicker, preparing it for the ovum (or egg). If the ovum is fertilised, this thickened uterine lining will provide nourishment for the embryo in its earliest stages.

Once the estrogen levels rise to a certain point, they trigger the release of additional hormones from the brain, which in turn cause the mature follicle to burst open and release the ovum. About midway through the average menstrual cycle, usually at about the 14th day, the ovum leaves the ovary during the process known as ovulation. Also during ovulation, the blood supply to the ovaries increase and the ovary moves closer to the fallopian tubes as ligaments contract in response to a surge in hormones and an increased blood flow.

At this time, the mucus released by the mouth of the uterus, or cervix, changes in characteristic from a thick substance to a stretch, viscous fluid, with a consistency which is often compared to that of egg whites. These changes in cervical fluid help facilitate the movement of sperm upward through the vagina, helping increase the likelihood of conception. In addition, the nature of the mucus is “friendly” to sperm – that is, both the consistency and the acidity level of the mucus help sperm survive what would, during other times of the menstrual cycle, be a hostile environment. Monitoring these changes in the cervical mucus can play an important role in determining fertility cycles and pinpointing the time ovulation occurs.

Once it leaves the ovary, the ovum travels through an opening called the fallopian tube, into the uterus. The egg is moved along by tiny hairlike projections, called cilia. It is during ovulation, or two or three days before, that a woman is most likely to become pregnant.

In most cases, the egg becomes fertilised and implants itself into the wall of the uterus. The fertilised egg is now known as an embryo. If the egg becomes fertilised and implants in the fallopian tubes, a tubal or ectopic pregnancy occurs. These pregnancies can be dangerousand even life-threatening if not detected early, and the embryo must be removed. If caught early enough, medication can be used to halt the development of the embryo.

If the egg does not become fertilised during ovulation, the egg will be shed along with the thickened uterine lining during the next menstrual cycle, and hormone levels will return to their pre-ovulation levels.

Tracking the menstrual cycle and understanding and recognising the changes that occur during the cycle are at the heart of many methods and techniques used for improving a couple’s chances of successfully conceiving. Taking some time to learn what is happening in your own body during your monthly cycle can help you conceive, and can also help you develop a healthy awareness of your body and the changes it must undergo each and every month, from puberty until menopause.