Anovulation occurs when an egg does not release, or ovulate, from a woman’s ovaries. Chronic anovulation is a common cause of infertility. According to the National Institutes of Health, these conditions account for almost 30 percent of female infertility.
Anovulation is typically, although not always, coupled with irregular or lack of menstruation. However, with anovulatory cycles, there may be bleeding, which a woman may mistake for a normal menstruation, although this would only rarely occur on a regular, monthly basis.
Ovulation begins to happen when the hypothalamus (a gland in the brain) secretes gonadotropin-releasing hormone (GnRH), which then causes the pituitary gland (another gland in the brain) to release follicle stimulating hormone (FSH) and luteinizing hormone (LH).
FSH stimulates the woman’s eggs (follicles) that then make the hormone estrogen, which builds the uterine lining. Next comes the release of LH (“LH surge”), which serves to release the egg from the ovary and into the fallopian tube.
At this point, fertilization by the male’s sperm must take place within 12-24 hours, or the egg will no longer be viable. If fertilization occurs, the embryo will reach the uterus and attach to the wall of the uterus in about five days after ovulation, establishing a pregnancy.
If fertilization does not take place, the progesterone levels will decrease and the uterine lining will shed with a menstrual period.
A high BMI, or body mass index, can cause a chemical imbalance to occur when there is an excess of androgens such as testosterone.
Excessive stress or anxiety can cause GnRH, LH and FSH to become imbalanced.
A low BMI or regular intense physical exercise can negatively impact the woman’s pituitary gland. This may cause the pituitary gland to not produce enough LH and FSH.
Thyroid stimulating hormone (TSH) and prolactin are two hormones released by the brain. Imbalances in either one of these can interfere with ovulation.
The most defining feature in diagnosing anovulation is simply the absence of regular menstruation. Other tests that may be performed during the evaluation include:
Generally, if a woman menstruates on a regular schedule, especially with the accompanying symptoms of bloating, mood change or breast tenderness, she is ovulating. Ovulation predictor kits can identify the LH spike that occurs with ovulation. Although not commonly used, basal body temperature charting (testing body temperature daily to identify the rise associated with ovulation) is another option to identify ovulation. A physician can also check for ovulation by testing the serum progesterone levels.
Lifestyle modifications can be the first step for overcoming anovulation.
Many fertility diets have been proposed. Ultimately, the best fertility diet is the one a woman can maintain over the long term. Many women try a challenging diet, lose a few pounds, but are unable to keep on the diet. Social support (talking to others, sharing recipes and tips) can be very helpful during this time.
Similar to a practical diet that can be maintained, a “real world” exercise program is beneficial. Again, social support such as going on walks together, going to the gym together, and similar group activities may make the activities more likely to be sustained.
We often recommend medical treatments in tandem with lifestyle modifications. Medications such as clomiphene citrate, aromatase inhibitors, insulin-sensitizing agents, or gonadotropins may be prescribed. IVF or intrauterine insemination (IUI) may be recommended to have a baby in certain circumstances.