Women with hypothyroidism (low thyroid) are treated with thyroid replacement. Such therapy usually corrects any ovulatory dysfunction. Women with milky breast discharge from both breasts and hyperprolactinemia (increased prolactin hormone) can be adequately treated with medications to lower their prolactin level. Lowering the prolactin usually results in spontaneous ovulation and eventually pregnancy.
Ovulation induction is also used during in vitro-fertilization (IVF). In this case, women who are having trouble conceiving undergo a process called controlled ovarian hyperstimulation (COH) in order to produce multiple eggs. These are removed from the ovaries and then fertilized by sperm in a laboratory dish before being placed in the uterus.
Women undergoing IVF usually utilize injectable gonadotropins to enhance ovulation. In IVF, the gonadotropins produce multiple follicles, which, when they are mature, are aspirated via the vagina and fertilized in the laboratory. This allows production of multiple embryos, which later can be transferred to the fallopian tube or uterus, resulting hopefully in implantation and pregnancy. There are multiple strategies for IVF. Most of these utilize birth control pills followed by a medication known as GnRH-agonist available in United States under the trade name Lupron or Synarel. This medication puts a woman in a temporary menopause-like state allowing her physician to control the timing of ovulation. This is then followed by the use of the gonadotropins mentioned above. Because GnRH-agonists cause temporary menopause, they are oftentimes associated with hot flashes, vaginal dryness, memory changes, and headaches.
Similarly, ovulation induction is also utilized in egg donation, a process where a woman may produce multiple eggs to donate to another woman.
Ovulation induction utilizing gonadotropins can result in a conception rate of around 80 to 90 percent in women with hypothalamic-pituitary dysfunction after six treatments cycles. In women with polycystic ovarian syndrome, pregnancy rates are slightly lower. Miscarriage rates are around 15 to 20 percent in patients with hypothalamic-pituitary dysfunction. They are higher in women with polycystic ovarian syndrome.
Success rates of women undergoing COH or IVF depend on a number of factors, including whether or not there is a sperm dysfunction in the male partner, or a disease of the fallopian tubes. However, the most important factor determining the success rate of ovulation induction remains the age of the female patient. This is due to a increased genetic abnormalities in a woman's eggs as she grows older. This fact is also reflected in the higher miscarriage rates that occur in older women. Currently most good IVF programs have an approximately 30 percent delivery rate following IVF, and 20 percent following COH.
Ovulation occurs in 80 percent of women with polycystic ovarian syndrome who are using clomiphene citrate (see above). However, as has been mentioned, only 40 to 50 percent of women will eventually conceive. The success rates are higher in women without any other fertility problem. Therefore, it is possible to reach a cumulative pregnancy rate of 75 percent in six months of the therapy. Most of those pregnancies occur in the first three months of the use of the medication, and very few occur after six months. As a result, the use of clomiphene citrate is usually limited to six months of therapy.
Multiple pregnancy occurs in around five percent of patients taking clomiphene citrate. Very few patients will have more than twins. However, multiple pregnancy rates are higher in women taking gonadotropins, frequently reaching 20 to 30 percent. Triplets and higher order pregnancies occur in 2 to 3 percent or less of pregnancies following the use of gonadotropins.
By closely monitoring women, physicians may be able to detect the number of the developing follicles and therefore control to some degree the multiple pregnancy rate. Most women have to be counseled ahead of time about the risk of multiple pregnancy to not only the mother, but also the fetus. Multiple pregnancy fetuses are at risk of prematurity and possible long-term disability.