Polycystic Ovary Syndrome is a hormonal disorder affecting 5-10% of women, and is the most common cause of treatable infertility. Women with PCOS have irregular or prolonged menstrual periods associated with numerous small collections of fluids, called cysts, that interfere with the release of an egg or oocyte.
Infertility is defined as the failure to achieve pregnancy after 12 months of regular, unprotected sexual intercourse.
To understand the answer to the question, “Why does it take women with PCOS longer to get pregnant?”, it is important to know first how the normal menstrual cycle occurs.
Normal menstrual cycle
This sequence of events occurs once every month and involves the ovaries, brain, pituitary gland (located in the brain), and uterus to help prepare the body for pregnancy. The pituitary gland produces two hormones: Follicle-Stimulating Hormone (FSH) and Luteinizing Hormone (LH). Progesterone and estrogen are two hormones that are developed in the ovaries.
During the first half of the cycle, a follicle containing egg or oocyte occurs in the ovary due to an increase in FSH. The follicle triggers the estrogen level to rise. This increase in estrogen causes the lining of the uterus to thicken, and stimulates the pituitary to release large amount of LH. The LH surge that occurs during the mid-cycle results in ovulation (release of oocyte from the follicle).
If this egg is fertilized by the sperm, it develops into an embryo (unborn offspring in the process of development). The embryo travels through the fallopian tube to the uterus. After ovulation, the ovary also produces progesterone. Progesterone prepares the uterus for implantation of the embryo. If the egg is not fertilized by the sperm, the lining of the uterus sheds causing the menstrual period.
What happens with PCOS?
In women with PCOS, small cysts approximately 4-9 millimeters in diameter accumulate in the ovaries. Research has shown that women with PCOS have a type of low-grade inflammation that can stimulate cysts in the ovaries. There is an imbalance in the hormones (estrogen, progesterone, LH and FSH) that maintain a normal menstrual cycle and ovulation. Ovulation or release of an egg does not occur because of this hormone imbalance, which results in irregular or absent periods, or loss of an opportunity to get pregnant. High levels of LH cause an increase in androgens. Androgens are male hormones normally produced in both men and women in differing amounts. Androgens include Testosterone, Androstenedione, Dehydroepiandrosterone (DHEA), and DHEA sulfate (DHEAS). These are produced by the ovaries and adrenal glands.
Treatment of infertility associated with PCOS
Though PCOS is one of the causes of infertility, the good news is that the chance of getting pregnant using fertility treatments is good. Methods and treatments that can help include:
Maintain a healthy weight
PCOS is associated with elevated levels of insulin in the blood and insulin resistance. Excess insulin can increase androgen production, causing difficulty with ovulation. The imbalance of hormones also produces excess androgens, which are male hormones normally produced in both men and women, in differing amounts.
Weight loss can reduce insulin and androgen levels. This may restore ovulation. Work with your doctor and dietitian to design a weight loss program. This will include a well-balanced low-calorie diet combined with moderate-intensity exercise activities.
Clomiphene is a synthetic estrogen-like hormone that acts on the hypothalamus (part of the brain), pituitary, and ovaries to increase FSH and LH. The increase in the FSH level improves the chance of developing an ovarian follicle that can trigger ovulation.
It is estimated that approximately 80% of women who had problems with ovulation may ovulate, and 30-40% may become pregnant after taking Clomiphene.
Letrozole causes an increase in FSH, which improves the chances of developing a follicle that can trigger ovulation. It can also increase the number of eggs released during the monthly cycle.
Metformin, widely used in the treatment of Type 2 Diabetes, can also be recommended for women with PCOS experiencing ovulation problems. Metformin also can help with weight loss and slow the progression to Type 2 diabetes if you have prediabetes.
Gonadotrophins are a second-line of treatment in women who do not ovulate or conceive with Clomiphene. Gonadotropins are hormones (LH and FSH) normally produced by the pituitary gland that stimulates the ovaries to produce a follicle containing an egg or oocyte. Gonadotrophins used for infertility are produced in a laboratory and are injected under the skin to stimulate a woman’s ovaries to produce follicles containing an oocyte (egg).
The Takeaway message:
PCOS is a hormonal imbalance that interferes with the growth and release of eggs. By regulating your menstrual cycles, you can increase your chance of getting pregnant by maintaining a healthy weight and other treatment options. Having PCOS does not mean you can never get pregnant. Work with your healthcare team to understand and explore all the options to achieve pregnancy.