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Fertility
Medications- Clomid, Follistim, Repronex, Gonal-F, Bravelle, Menopur, Progesterone,
Metformin, Lupron, Ganirelix, Cetrotide, Ovidrel, hCG
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 NY fertility 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. Our New York fertility clinics are conveniently located for patients requiring monitoring.
When a patient undergoes ovulation
induction 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.
Directions to Our New York Fertility Clinics
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