Finding Out Why Your Periods are Abnormal
The two critical facts I need to know about a fertility patient who is having irregular or absent periods are:
- Can you menstruate?
- Can you ovulate?
Once I've answered these questions, I have a good idea of what's causing your fertility problem.
I'd like to share this information with you, as well as some of the questions and concerns my patients have brought up from time to time.
What Makes You Have a Period?
Normally each month estrogen and progesterone stimulate the growth of the uterine lining. When the progesterone-producing corpus luteum deteriorates toward the end of the cycle, "progesterone withdrawal bleeding" occurs: you have a period. Waves of vasoconstriction (blood vessel spasms) restrict the blood supply to the endometrium and thus provoke the onset of menses. At the conclusion of menses, clotting factors seal off exposed bleeding sites, and resumed estrogen production begins restoring the endometrium.
Several basic tests will help determine why your periods are abnormal. Table 12-1, "Diagnostic Approaches for Irregular Menstrual Periods or Amenorrhea," which appears later in this chapter, will give you an overview of the diagnostic approaches used to determine if you are ovulating and the conditions that can interfere with ovulation and menses.
This may seem surprising, but pregnancy is the single most common reason for women reporting to me that their periods have stopped. Before I initiate any type of fertility treatment, I conduct a pregnancy test to rule out the possibility of pregnancy.
Cervical Mucus Smear
Normally the cervical mucus is thick and relatively impervious to the outer environment. Throughout the first half of the cycle, increasing amounts of estrogen produced by the ovary cause the mucus to "fern." When placed on a slide and dried, the estrogen-primed mucus crystals form a beautiful fern-like pattern. Around the time of ovulation, high estrogen levels transform the mucus into a clear, watery, viscous fluid that sperm can easily transverse. After ovulation progesterone from the corpus luteum "opposes" the action of the estrogen, and the mucus once again thickens. I use this simple test to tell me if you've ovulated during this cycle. If you have not yet ovulated, I will observe the telltale ferning. I will then perform the progesterone withdrawal test to find out if you are capable of menstruating.
Transvaginal ultrasound is a sample painless procedure that can be performed in less than 15 minutes. It provides helpful information that unlocks the clues to your ovulation problem. This picture demonstrates a 12mm "triple-line" pattern indicating normal estrogen stimulation. As your follicles develop and release estrogen, the uterine lining thickens and takes on a very specific appearance. Immediately prior to ovulation in a natural cycle, the endometrium measures 8-12mm and follicles reach 20-24mm, while if you are receiving ovulation medication follicles may be ready at 16-18mm. After ovulation, the endometrial echo (shadow) becomes more opaque (white) indicating that the corpus luteum is now making progesterone.
If your ovaries are not making estrogen the endometrium will be thinner, 6mm or less and the ovaries will usually contain either many small follicles surrounding the margin of the ovary (polycystic ovaries) or no follicles at all. This may be due to ovarian failure or abnormal hormonal stimulation. You will soon learn how I can decide which is causing your menstrual cycle problems.
Progesterone Withdrawal Test
The progesterone withdrawal test will confirm if your uterus is capable of menstruating. If it is, then the cause of your menstrual irregularity lies with your hormonal systems. If your uterus cannot "bleed," then the problem lies with the uterus itself.
I can bring on your period either by giving you oral progesterone over a five- or ten-day period or by giving you a progesterone injection. After taking the progesterone, your period should begin within fourteen to twenty days.
Positive Response to Progesterone Withdrawal
If progesterone withdrawal causes your period to start up, as it did with Kathy S., I learn a number of things.
First, I know that your ovaries are producing enough estrogen to build up your uterine lining. I also know that your uterus is capable of responding to estrogen and progesterone stimulation. Since your uterus is functioning normally, your fertility problem lies somewhere in your hormonal system.
Second, you are failing to menstruate because you are failing to ovulate. For some reason your pituitary is not producing the LH spike necessary to release the ovum from your follicle.
Two conditions must exist before your pituitary will release an LH surge: The follicles growing in your ovaries must release enough estrogen to signal your pituitary that it's time to release the LH surge-in other words, that at least one egg has reached maturity. And your pituitary gland must be capable of generating the LH spike.
I may suspect that your hypothalamus just isn't prodding your pituitary well enough. If your follicles do not grow to maturity, you'll never produce enough estrogen to trigger the LH spike to release the egg and thus ovulate. A pituitary malfunction can cause the same problem; however, in Kathy's case, I suspected a hypothalamic insufficiency from excess running.
"How can you be sure?" Kathy asked.
"Well, that's exactly what my next series of tests will show. I want to make sure that other systems in your body are not adversely affecting your hormonal system."
Negative Response to Progesterone Withdrawal: Repeating the Progesterone Withdrawal After Estrogen Stimulation
Like Kathy, most women will "bleed" in response to progesterone withdrawal. However, if you don't, it's possible that your estrogen supply is not adequate to stimulate uterine lining growth. If your uterus is normal, taking estrogen to prime the growth of the uterine lining should guarantee that you'll have a period after progesterone withdrawal. So we'll try it again-this time giving you estrogen before the progesterone, just to be sure.
If the estrogen/progesterone-stimulated cycle fails to produce a "bleed," it means that your uterus cannot respond to estrogen and progesterone stimulation: we've pinpointed your uterus as the problem. My next step will be to examine the inside of your uterus. (I'll discuss uterine abnormalities, hysteroscopy, saline sonohysterography, D&C, and uterine X-ray procedures in chapters 16 and 19.)
Positive Withdrawal to Estrogen/Progesterone Stimulation
When you have a period after taking estrogen and progesterone, I know that your uterus is capable of menstruating. The reason you have not been menstruating is that your ovaries are not producing adequate amounts of estrogen. At this stage in the diagnostic procedures we don't know for certain why your ovaries are not producing estrogen, but several possibilities exist:
- Your ovaries are not capable of producing estrogen,
- Your hypothalamus is not stimulating your pituitary to release FSH and LH, which control follicular development and estrogen production,
- Your pituitary is unable to produce adequate amounts of LH and FSH,
- Other hormonal imbalances are tricking your pituitary into "thinking" that it's doing a good job when, in fact, it is not.
Since estrogen stimulation is vital for the growth of the uterine lining, I will measure your estrogen hormone levels to confirm this diagnosis before venturing into new diagnostic territories. I'll may also do a cytology smear to look at estrogen stimulation of your vaginal cells. In addition, I'll measure your FSH level to rule out ovarian failure. (A high FSH level indicates that the ovaries have been severely damaged or have run out of eggs.)
Detecting Ovarian Failure
Ovarian failure occurs when your ovaries are severely damaged or when they run out of eggs. When this happens, your pituitary gland tries to force your ovary to manufacture estrogen and to ovulate by working overtime to produce FSH. The pituitary gland's signals fall on deaf ears, though, because the damaged ovaries cannot respond to the extra FSH stimulation.
Ovarian failure may be caused by a number of conditions including infection, chemical toxins, medications, radiation exposure, tumor, surgery, immunologic dysfunction and genetic abnormalities. Unfortunately ovarian failure is rarely reversible. However, ovarian failure due to infection or endometriosis will sometimes respond to treatment. Since a diagnosis of ovarian failure can be distressing, I always repeat the FSH test before recommending donor eggs or other alternatives.