Fertility medications are the primary treatment, alone and in combination with assisted reproductive techniques, for women with ovulation dysfunction. In general, their purpose is to cause the release of hormones that trigger or regulate ovulation.
Often the first choice for treating infertility, clomiphene citrate, sometimes referred to as Clomid, is an oral medication. It is a very commonly prescribed medication that has been used for decades in infertility treatment. It works by increasing the production of hormones from the area of the brain called the pituitary gland. These hormones stimulate the ovary to recruit and develop a mature egg that is then released through ovulation. Most patients do not have side effects from clomiphene citrate; although possible side effects include multiple pregnancy, hot flashes and, more rarely, headaches or visual disturbances.
Gonadotropins are injectable medications used to treat patients with infertility or ovulatory dysfunction, and can be used in an Intrauterine Insemination (IUI) or In Vito Fertilization (IVF) cycle. There are many different preparations available; all contain Follicle Stimulating Hormone (FSH), a hormone normally made by a woman’s pituitary gland that causes the eggs in the ovaries to ripen. When gonadotropins are used, multiple eggs typically develop. Thus, when gonadotropins are used in an IUI cycle there is a risk of multiple pregnancy occurring. During an IVF cycle, there is a risk of ovarian hyperstimulation syndrome if too many eggs develop. For these reasons, we monitor our patients very carefully to adjust dosing as appropriate. Additionally, given the type of protocols we use during IVF cycles, the risk of ovarian hyperstimulation syndrome is exceedingly low.
Letrozole is an oral medication that acts as an aromatase inhibitor, temporarily decreasing the production of the hormone estrogen. Typically, letrozole is used in the treatment of patients with breast cancer whose tumors are sensitive to estrogen. Recent studies have suggested that letrozole can help induce ovulation, or the release of an egg from the ovary, in women with irregular menstrual cycles. Currently, we have lengthy experience with certain medications, such as clomiphene citrate and injectable gonadotropins to assist with the induction of ovulation. However, despite many studies suggesting its safety and efficacy, letrozole is not yet approved by the FDA for use in fertility treatment. Therefore, although commonly used for fertility treatment, letrozole is considered an off label medication for this purpose.
Letrozole has a half-life of only two days, which means that when taken in the early part of the menstrual cycle, it should be eliminated prior to the time of ovulation. Most patients do not have side effects with letrozole, although possible side effects include multiple pregnancy, mild nausea, fatigue or joint and muscle pain. Recent studies have suggested that letrozole may be more effective than clomiphene citrate in women with polycystic ovarian syndrome.