Many fertility drugs are now available to treat infertility in the female and most are used to induce regular ovulation. Ovulation is caused by a series of hormonal interactions monitored and controlled by the hypothalamus. The hypothalamus is a small gland located at the base of the brain that serves as a regulator for many hormones, including follicle stimulating hormone (FSH), luteinizing hormone (LH) and estrogen. The hypothalamus produces gonadotropin-releasing hormone (GnRH) which travels to the pituitary and stimulates the production of follicle stimulating hormone. FSH causes the recruitment and development of eggs within the ovarian follicles.
Clomid is an oral medication used to induce ovulation. It works at the hypothalamus where it competes for “receptor sites” with estrogen. In a normal “unstimulated cycle”, estrogen levels increase as the follicles grow signaling a reduction in the production of FSH. Clomid causes the hypothalamus to “miss read” that estrogen levels are low and this signals the pituitary to increase its production of FSH, which stimulates follicular development. Fertility specialists agree that more than three ovulatory cycles of Clomid should not be administered. Pregnancy is most likely to occur during the first three cycles.
Clomid is widely used by obstetrician/gynecologists and infertility specialists. Pregnancies using Clomid usually occur during the first three ovulatory cycles and use beyond that point is not recommended; however, specialists often see women who were on Clomid for much longer times. Prolonged treatment with Clomid is rarely successful, and can produce serious side effects.
Glucophage (metformin) has recently come into use for the treatment of polycystic ovarian syndrome (PCOS). Metformin is a member of a class of drugs known as insulin sensitizing agents, and a high percentage of women with PCOS are insulin resistant (hyperinsulinemic). Our clinic offers advanced treatments for patients suffering with PCOS.
The body tries to compensate for insulin resistance by producing large quantities of insulin, which leads to excess androgens (male hormones). This results in ovulatory irregularities and the characteristics of excess body hair, classic body shape, etc. seen in the PCOS patient. Many times metformin will correct hyperinsulinemia, which will consequently lower male hormone production and establish normal ovulation.
Gonadotropins are used to directly stimulate follicular development, especially in assisted reproductive technology cycles (IVF). The first gonadotropin introduced in the United States was Pergonal and it was derived from the urine of postmenopausal women. In addition to FSH, it contained luteinizing hormone, which many specialists believe leads to a better stimulation cycle.
Newer pure FSH preparations such as Follistim and Gonal-F are derived from genetically engineered mammalian cells. Gonal-F and Follistim are identical to the FSH produced by the body and contain no impurities. Bravelle is a highly purified urinary product with 75 IU of FSH and less than 2% LH. Menopur is also a urinary derived product with equal amounts and FSH and LH. Repronex is a urinary gonadotropin similar to Pergonal that is less expensive than Follistim and Gonal-F. Bravelle, Follistim, and Gonal-F can be administered by subcutaneous injection. These drugs are administered under close supervision by a trained fertility specialist to maximize the chances of pregnancy and avoid potentially serious side effects.
Patients receiving gonadotropins must have periodic measurements of estradiol levels along with ultrasound examinations. These tests are used by the specialist to adjust dosages as the follicles develop and to avoid potential side effects.
When a patient undergoes ovulation induction it is very important for the physician to control the production of various hormones. Lupron, Antagon, or Cetrotide are used to down regulate patients who are undergoing therapy with FSH. These products inhibit the body’s natural production of FSH, LH, and estradiol and ovulation cannot occur until an external source of hCG or LH is administered.
Lupron and Antagon allow the physician to take control of the ovulatory cycle. FSH is administered until the physician judges that the follicles are ready for retrieval. An injection of hCG (Pregnyl) or Ovidrel (recombinant hCG) is given to induce egg release from the follicle, or “prepare” the egg for retrieval. The egg(s) can require up to 50 hours to make its transit from the ovary through the fallopian tube(s) to the uterus. In an IVF cycle, egg retrieval is scheduled 34-36 hours after the hCG injection.
Sometimes anovulation is caused by elevated levels of prolactin, which is the hormone responsible for breast milk production. Elevated levels of prolactin in women who are not pregnant are usually a result of a benign tumor located on the pituitary gland. Parlodel or bromocriptine are medications used to treat hyperprolactinemia and surgery to remove the tumor is sometimes performed by a neurosurgeon.
Progesterone is administered, especially an ART cycles, to help support the endometrial thickening that occurs as the uterus is prepared to accept the embryo. Many other medications such as steroids, birth-control pills, antibiotics will be prescribed for appropriate clinical conditions.
The fertility drugs used in hormonal therapy and in IVF treatment include:
Follicle Stimulating Hormone (FSH) (Follistim®, Bravelle®, Gonal-F®) stimulates the ovaries to produce more follicles, thus increasing the number of eggs. These medications may be prescribed to be injected intramuscularly (into a muscle) or subcutaneously (under the skin).
Human Chorionic Gonadotropin or hCG (Profasi®, Pregnyl®) is a hormone that matures the developing follicles and triggers release of an egg from its follicle. It is taken as an intramuscular (IM) injection.
Progesterone is a hormone that helps prepare the endometrium, the lining of the uterus, for the arrival and implantation of an embryo. Progesterone is delivered by intramuscular (IM) injection or by vaginal suppository
Leuprolide Acetate (Lupron®) acts on the brain to suppress the body’s own hormone production, thus preventing follicle development and egg release. Doctors use it in combination with other medications to improve their control of the woman’s cycle.
Antagonist (Cetrotide®, Ganirelix®) these medications are used for pituitary suppression in an IVF cycle.
Houston IVF provides a wide variety of fertility services to meet the special needs of the patient. If you are interested in learning more about our location in Houston, fertility drugs details, or about patient care, please feel free to contact us or call (713) 465-1211.