Women Talk: Why we menstruate

Chona, a homemaker, came to see me because her 13-year-old daughter Amy had been asking questions about menstruation. Almost all the girl’s classmates had been having their periods, but Amy had not started hers. Chona herself had her first period when she was 10, so the mother also began to worry.

I told Chona that every girl will have her own period in due time, and Amy’s situation is not alarming unless there is really something wrong with her, organically, or functionally. I examined Amy and noted that her breasts were starting to develop. She also had very fine hair in her armpits and pubic area. Unless there is reason to think of pelvic organ abnormalities, I usually do not do a rectal exam, or even request a pelvic ultrasound for 13-year olds who have not yet menstruated. Most of the time, a gentle reassurance both to the mother and the daughter is all that is needed, giving the girl time to mature some more. The cut-off age is usually 18 years old, (some doctors would say 16 or 17) when the gynecologist will start doing an endocrine work-up.

But how does menstruation start, really? And what causes this cyclic event to occur each month?

Three important areas

There are three areas, or levels, that are involved in menstruation. The highest is the brain center, in areas called the hypothalamus and the pituitary. The next area would be the ovaries, of which females have two, the right and the left.  And the final one is the uterus, specifically its lining, called the endometrium.

When the girls are between 11 to 15 years old, the hypothalamus, and then the pituitary from the brain send out hormones targeting the two ovaries to “wake up” the dormant egg cells contained in them. A girl is born with a finite number of eggs, and this number dwindles every month as she ovulates (extrusion of the egg) and menstruates. The stimulated ovaries will begin to secrete the ovarian hormones (estrogen and progesterone) in a cyclical manner, and this causes the maturation of an egg each month.

When fully matured, this egg comes out of the ovary (ovulation). When ovulation occurs, hormones from the ovaries causes the growth of the lining of the uterus (endometrium) making it thick and velvety. This is nature’s way of preparing the lining in case a pregnancy occurs, so that the fertilized ovum (which is the product of the fusion of the mature female egg and the male sperm; and is very different from the mature egg that was extruded) can easily embed itself in this “cushiony” environment and start growing. The cervical mucus, too becomes thin and slippery, to aid the movement of the sperm if sexual intercourse occurs. In girls, this uterine lining also grows thick, but because no pregnancy occurs, ovarian hormones decrease, and the hormonal support for this lining also decreases. This useless thickening then “crumbles” as it has no use, and slowly comes out of the vagina as menstruation. A physiology professor once referred to menstruation as “the bloody tears of a frustrated uterus!”

Menstruation reduces the endometrial lining to about a third of its previous thickness, and only the basal layer remains. When this occurs, the brain center will detect this low level of ovarian hormones in the system, and again sends hormones to stimulate the ovaries. Thus stimulated again, the ovaries will nurture another dominant follicle inside it to become a mature egg, which will be released during ovulation. The cycle is thus repeated in a cyclic manner, occurring every 28 days, with ovulation tagged as Day 14, or 14 days after the menses. The first day of menstruation is considered Day 1.

Because a young girl’s body system needs to mature, menses during this time may not be regular – she may miss a few months’ periods, or there may be differences in volume of the menses. Her body will slowly mature, until she finally establishes her own menstrual cycle. In a textbook case, the woman menstruates every 28 days. However studies show that no woman menstruates in this ideal, clock-work scenario. Many things will affect the menses: external stimuli, like fatigue, sleeplessness, worry, sickness, drastic lifestyle changes, like moving houses, transfer to a new school or a foreign place, a change of work place, and even getting married!

In Amy’s case, it is possible that her brain centers are still immature, so there is room for waiting. This is the best time to explain to her the whys and hows of menstruation in a very simple, understandable manner, mainly to reassure her that over a few months, her menses will soon start.

Dispelling menstrual myths

This is also the time to reinforce advice on hygiene and dispel many menstrual myths that had been handed down from our grandmothers. Showering often, which is strongly recommended during the menses, will not cause “rayuma” or painful joints when we grow old. Eating sour food during the menses will not cause dysmenorrhea; but the salt added to these sour fruits might cause some water retention, which could bring about a feeling of bloatedness. Taking cold baths will not stop the menses; also, one could still engage in sports, even the very physical ones, during menses; the flow will not increase.

However, there is truth to the belief that the female eggs could get “old.” Although women are born with1 to 2 million oocytes (precursors of the mature eggs) at birth, many are lost throughout her life. Even if only one becomes mature every month, many undergo atresia (loss of viability) and die out as well. The quality of the egg suffers too, as the woman grows older, and the ability to be fertilized becomes lesser after 35 years old. This is not to say that a woman after 35 could not conceive, but compared to another woman who is between 22 to 28 years old, and all things being equal, her chances of conceiving, and conceiving a normal child, is so much less.

Both Chona and Amy heaved sighs of relief after learning about these, and they left my clinic smiling. — BM, GMA News

Dr. Alice M. Sun-Cua is an author and practicing obstetrician-gynecologist at the San Juan de Dios Hospital in Pasay City.