Irregular menstrual cycles

I’ve had a lot of questions from many of you about your irregular menstrual cycles. Shelly and Ciara just recently came in for a recheck because they are frustrated and searching for a solution. “I don’t understand Dr. Boyd, why my period will be normal for 2 or 3 months and then it will come so heavy that I pass clots, have cramps and soak 4 or more tampons in 30 minutes for the first couple days. Then I might skip a period or just spot for a few days, and then back to normal for a few months, then spotting or heavy it drives me crazy. Is something serious wrong with me? Will the pill help? What can I do?”

I am finding that more women than ever seem to be having problems with abnormal uterine bleeding, that presents younger as women (pre-teens) are menstruating at a younger age. Teens and young women are struggling with weight more now than ever and much of it has to do with the hormones that have been introduced into our food supply in greater and greater amounts over the past few years.

Ingesting excess hormones every day via dairy and meat products has been shown in several studies to affect growth (size, weight, and height) in children and possibly sexual development, fertility and menstrual irregularities. This becomes more of a concern as we continue to see childhood obesity increase and weight changes in women (up or down), can cause abnormal uterine bleeding and infertility. The thyroid gland is also important in menstrual regulation and can be affected by the hormone overload caused from animal sourced food products, pesticides, chemicals and plastics in our environment.

One way to gain understanding is to review the ‘normal’ menstrual cycle, then we can compare it to Shelly’s and Ciara’s problems next week and maybe see what is going on. Menstruation usually starts at about age 12 or 13. One study, however, has indicated that girls may be starting puberty earlier than in the past. By the age of eight, 48% of African-American girls and 15% of white girls were showing pubic hair and developing breasts. It had previously been thought that only 1% of girls exhibited such changes at that age. Alternatively, a study done in England found that the average age for the onset of menstruation has changed very little since the 1950s, with the median age being 13 years.

The uterus is a pear-shaped organ located between the bladder and lower intestine. It consists of two parts, the body and the cervix. When we are not pregnant the body of the uterus is about the size of a fist, with its walls collapsed and flattened against each other. During pregnancy the walls of the uterus are pushed apart as the fetus grows. The cervix is the lower third of the uterus. It has a canal opening into the vagina this opening is called the os which allows menstrual blood to flow out of the uterus into the vagina.

Leading off each side of the body of the uterus are two tubes known as the fallopian tubes. Near the end of each tube is an ovary. Ovaries are egg-producing organs that hold between 200,000 and 400,000 follicles that contain the genetic material for producing babies. The inner lining of the uterus is called the endometrium and during pregnancy it thickens and becomes enriched with blood vessels to house and support the growing fetus. If pregnancy does not occur, the endometrium is released as your period. The hypothalamus (an area in the brain) and the pituitary gland regulate the reproductive hormones. The pituitary gland is often referred to as the master gland because of its important role in many vital functions, many of which require hormones. In women, six key hormones serve as chemical messengers that regulate the reproductive system.

The hypothalamus first releases the gonadatropin-releasing hormone (GNRH)>
This chemical, in turn, stimulates the pituitary gland to produce follicular stimulating hormone (FSH) and Lutinizing Hormone (LH).

Estrogen, progesterone and testosterone are secreted by the ovaries at the command of FSH and LH and complete the hormonal group necessary for reproductive health.
The menstrual cycle reflects the changes that occur in the endometrium, the inner lining of the uterus. Layers of the endometrium are shed at the end of the cycle as part of menstrual flow. The menstrual cycle is generally divided into phases; the follicular phase, ovulation phase and the luteal (or secretory) phase.

For a clear picture of the process it is important to understand how to count days in a menstrual cycle. Day one is generally considered to be the first day of bleeding. The follicular phase includes menstrual bleeding followed by proliferation (growth and thickening) of the endometrium, uusually lasting from day 1 to day 14. The following processes occur during this time.

The menstrual flow itself lasts an average of six days. Estrogen and progesterone levels are at their lowest during this time.

At the end of the menstrual flow, the proliferative phase begins, and the endometrium starts to grow and thicken. FSH levels rise and stimulate several ovarian follicles to mature over a two-week period until their eggs nearly triple in size. During this period, FSH also signals the ovaries to produce estrogen, which, in turn, stimulates a great surge of LH around day 14.

The surge of LH at the end of the follicular phase triggers ovulation by causing the largest follicle to burst and release its egg into one of the two fallopian tubes. At ovulation (usually day 14 in a 28-day cycle), the proliferative stage ends and the luteal (secretory) phase begins. The luteal (secretory) phase lasts about 14 days.

Once ovulation has occurred, LH causes the ruptured follicle to develop into the corpus luteum, a mound of yellow tissue that produces progesterone. The corpus luteum continues to produce progesterone and estrogen. When fertilization does not occur, the corpus luteum degenerates to a form called the corpus albicans (Latin for "white body"), and estrogen and progesterone levels drop.

Finally, the endometrial lining sloughs off and is shed during menstruation. It’s amazing how complicated our cycles can be it really makes you wonder how things go right most of the time. Next week we can take a look at what goes wrong now that we know how things should function.