4 Important Facts About Ovarian Stimulation
Injectable Drugs and Your Eggs
If you’re looking into fertility treatment with IVF, you’ve probably heard that drugs to stimulate ovulation play an important role.
Why are these needed? What do they do? Here are a few facts.
1. Hormones Cause Normal Ovulation
During their reproductive years, women have a period every month because they normally ovulate every month. A woman is born with all the eggs she will ever have. A hormone produced in the pituitary gland, called follicle-stimulating hormone or FSH, causes a group of follicles to grow more rapidly. Each month, one of those eggs will mature in a follicle on her ovary and be released, which is called ovulation.
If the egg is fertilized and implants in her uterus, a woman becomes pregnant. If not, the egg is shed with the lining of her uterus, called the endometrium, when she has her period. When a woman reaches her late 30’s or early 40’s, she may notice her periods become shorter. Eventually, she will begin to skip ovulation and skip periods. When a woman has not had a period for a year she has entered menopause.
2. Age and Diminished Ovarian Reserve
Fertility in women gradually declines starting in their 30’s. Over time, egg quality decreases as egg quantity declines. The decreasing number of egg-containing follicles is called loss of ovarian reserve or diminished ovarian reserve. Even though the average age of menopause is 51, most women do not remain fertile until then. Most women become unable to have a successful pregnancy somewhere in their mid-forties, according to the American Society for Reproductive Medicine (ASRM), whether naturally or by assisted reproductive technology.
Women with poor ovarian reserve have a lower chance of becoming pregnant than women with normal ovarian reserve in their same age group, according to the ASRM. Tests of day-3 FSH, antimüllerian hormone (AMH), and estrogen levels involve blood sampling on the 2nd, 3rd, or 4th day of the menstrual cycle. High levels of FSH or estrogen and low levels of AMH indicate that ovarian reserve is low.
3. Ovarian Stimulation
When you start fertility treatment, your fertility specialist will order tests to determine your FSH and estrogen levels. Based on the results of these and other tests, your treatment plan will be developed.
One type of fertility drug that is used to stimulate your ovaries is clomiphene citrate (brand names Clomid or Serophene.) Clomiphene citrate is used to stimulate eggs for IUI (artificial insemination); it is not used in IVF treatment. Your fertility specialist may prescribe a clomiphene citrate challenge test, or CCCT, to see how your brain responds to changes in estrogen levels. In this test, your FSH level is measured on day 3 of your cycle, you are given Clomid on days 5 through 9, and then your FSH level is tested again on Day 10. A poor response to the test may indicate lower response to injectable fertility drugs or other issues which affect your eggs.
4. Ovarian Stimulation for IVF— Not All Eggs Are Created Equal
The goal for ovarian stimulation in IVF treatment is to get your ovaries to produce multiple eggs without releasing them, so the eggs can be retrieved and fertilized in the laboratory. Because not every egg is of good quality, multiple eggs provide the best opportunity to select and fertilize the best grade and quality to produce a positive outcome.
Another type of fertility drugs that stimulate your ovaries are gonadotropins, such as hCG, hMG and rFSH. Gonadotropins are used in IVF and may be used in IUI. IVF helps prevent high-order multiple births (triplets or more) by controlling the number of embryos which are transferred, which helps protect both the mother and the baby from the risks of multiple births.
Your reproductive endocrinologist will monitor you closely when you are using gonadotropins. Monitoring will involve transvaginal ultrasounds and blood tests to see how your follicles (which serve as a ‘holder’ for the eggs) are developing, and to make sure you are not experiencing ovarian hyperstimulation. Ovarian hyperstimulation syndrome causes your ovaries to become swollen and painful. In most women the symptoms are mild and usually go away on their own in two to four weeks. Rarely, women experience rapid weight gain, abdominal pain, vomiting and shortness of breath. This can be serious, so be sure to report any unusual fluid buildup to your doctor.