Leuprolide acetate, a drug belonging to a class called gonadotropin-releasing hormone agonists, or GnRH agonists, is commonly administered as part of an in vitro fertilization, or IVF protocol. In vitro fertilization, a procedure used to increase an infertile couple's chance of achieving a pregnancy, involves stimulating a woman's ovaries to produce a larger than normal number of eggs. Transferring more than one embryo back to the uterus increases the odds of pregnancy. In some cases, leuprolide is given to women undergoing chemotherapy in an effort to preserve fertility sometimes lost during chemotherapy treatment.
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Leuprolide, which is chemically similar to GnRH, is a gonadotropin-releasing hormone, a hormone that stimulates hormone production. In a normal menstrual cycle, GnRH release produces a follicle-stimulating hormone, which stimulates estrogen production. GnRH also produces luteinizing hormone, which triggers ovulation, release of the mature egg from the ovary. When given in injection form, leuprolide first stimulates the ovaries, giving a "flare" effect, then "down regulates," or shuts down the ovaries, causing a temporary menopause effect by suppressing hormone production.
IVF Effects
Leuprolide is used in two IVF protocols. The first is a down regulation cycle. Leuprolide is injected daily starting after ovulation in the menstrual cycle prior to the IVF cycle. Leuprolide suppresses the ovaries completely before starting stimulation drugs. At the start of the menstrual period, leuprolide dosage is decreased but continued along with gonadotropins, which are ovary-stimulating drugs, until the follicles containing eggs mature. Continuing leuprolide prevents ovulation from occurring before the egg retrieval. In the second protocol, called a flare protocol, small doses of leuprolide are given for the first few days of the menstrual cycle. This causes a flare effect, raising the hormone levels, before starting gonadotropins. Leuprolide may be stopped at this point or continued until the follicles mature. Centers vary in the way they administer leuprolide.
Donor Synchronization
Leuprolide also is used to synchronize donor and recipient egg retrieval cycles. Women who are using a gestational carrier or women who are donating half their eggs to another woman often want to synchronize their menstrual cycles so that the recipient can do an embryo transfer without having to freeze the embryos. Since women don't always start their menstrual cycles at the same time, placing both women on leuprolide to suppress both their cycles allows medication to be started at the same time for both women.
Preserving Fertility
Women undergoing chemotherapy can suffer damage to their ovaries, which can lead to permanent infertility. Although its effectiveness has not been proven, some cancer centers give leuprolide to a woman of childbearing age before she starts chemotherapy for several weeks, then once a month during the duration of the treatment. Leuprolide can cause hot flashes, bone pain and decreased bone density, mood changes, fatigue, headache, loss of libido and vaginal dryness.
