regular for you may not be regular for someone else but having some sort of pattern to your periods is important because it indicates that you’re producing and releasing eggs on a regular basis. But just because a woman is having periods does not give us any further information about egg quality or whether her uterus can support a pregnancy.
Understanding the causes of malfunctioning menstrual cycles
Although it may seem like your menstrual cycle runs like clockwork, always appearing on the expected day, the likelihood is that at least part of the time, your cycle is out of sync, showing up too early, too late, or not at all, even though you’re not pregnant. Irregular periods not only make it hard to determine when you ovulate, but they can also indicate that your reproductive system is in need of fine-tuning. In this section, we discuss all the ways cycles can get out of sync, what it can mean, and how your doctor may suggest fixing them.
Menstrual cycles that don’t fall into the norm can indicate that you’re not ovulating at all or that you’re only ovulating occasionally. An occasional irregular cycle can be brought about by stress; a change in routine, exercise, or eating patterns; or illness, but periods that are “never the same length twice,” consistently shorter than normal or longer than normal, should be evaluated by your doctor.
Bleeding too often — short cycles
If your cycles are very short — less than 25 days apart on a regular basis, you may be ovulating too soon. Since the period between ovulation and the start of your period should consistently be 14 days, if your periods are short, it usually (but not always — we discuss the alternative in this section) means that you have a short follicular phase, the time between your period and your ovulation.
A short follicular phase can mean that the egg is developing in the incorrect time frame. Short follicular phases can occur when your ovarian reserve, the number of eggs you still have in your ovaries, is starting to decrease. It occurs because there is an elevation of the FSH level in the previous cycle, which accelerates the development of the egg. So, a clinical pearl is that short cycles may raise red flags about reduced ovarian reserve. A woman who has traditionally had cycles ranging from 28–32 days and then notices that they have shortened to 26–27 days may be showing signs of reduced ovarian reserve. This is especially true if she is over the age of 35.
For quite some time, a lot of emphasis was placed on the second half of the cycle or the luteal phase. If this was shorter than ten days, a diagnosis of luteal phase defect was made and sometimes progesterone was used to try to correct for this. While there may be some controversy about this, recent understanding of how the cycle works has suggested that there may not be a luteal phase defect. The luteal phase is dependent upon the first half of the cycle, the follicular phase. The follicular phase is dependent upon the quality of the egg. So short luteal phases are a product of poor egg quality.
Bleeding too infrequently or skipping periods
Cycles that are very long, over 35 days apart, can indicate that you’re not ovulating regularly. This can be a factor of excessive exercise, weight change, or other factors, but it can also be caused by polycystic ovary syndrome, or PCOS. PCOS can cause changes in hormone ratios that can be diagnosed by your doctor, as well as physical changes such as excessive hair, weight gain, and acne. (See Chapter 7 for more on PCOS.)
Endometriosis, premature ovarian insufficiency (see Chapter 7 for more on both of these), abnormal thyroid levels, or high prolactin levels (see Chapter 11 for the details on diagnosing infertility causes through blood tests) can also cause irregular or absent periods.
Bleeding between periods
Bleeding between periods can indicate that something is wrong inside your uterus or that your hormones are out of balance. Some of the things that can go wrong with your uterus to cause irregular bleeding are
Cervical irritations or infections: Possible causes of cervical bleeding especially if this occurs after intercourse
Fibroids: Benign growths found in the uterine wall
Polyps: Small fleshy growths found on the endometrium, the lining of the uterus, or the cervix
Bleeding too heavily (menorrhagia)
Bleeding too heavily and passing clots can be “normal” for some women, especially in women who are overweight. Fibroids, PCOS, and irregular periods can be related to heavier-than-normal bleeding. Heavy bleeding can also be a sign of recurrent early miscarriage (see Chapter 13).
Women who bleed heavily every month are at risk for becoming anemic (having a decreased number of red blood cells). Anemia can lead to fatigue and weakness, so heavy periods should be checked out with your doctor. A simple blood test can diagnose anemia.
Having scant periods
If your period is very light, it could be a normal variant (in which case, lucky you!), or it could be a sign that your uterine lining isn’t getting as thick as it should. Scant periods are typical if you’re using birth control pills or have just stopped using them, or if your periods have just started. If your lining isn’t thickening properly, you may not be ovulating normally, so seeing your doctor is a good idea.
Experiencing painful periods (dysmenorrhea)
Up to 40 percent of women experience pain with their periods, called dysmenorrhea. Dysmenorrhea falls into two categories:
Primary dysmenorrhea has no other underlying cause besides the release of prostaglandins (chemicals made by cells that have specific functions such as controlling body temperature, stimulating smooth muscle, and influencing heat cycles) in the uterus, which cause uterine contractions.
Secondary dysmenorrhea is caused by disease present in addition to the normal release of prostaglandins, such as endometriosis, fibroids, or infection.
The release of prostaglandins that
