INJECTABLE FSH MEDICATIONS
The use of follicle
stimulating hormone (FSH)
injections intramuscularly or subcutaneously results in
high levels of FSH circulating in the blood stream. FSH
acts directly on ovarian follicles resulting in recruitment
and stimulation of many eggs. Injectable FSH comes from
two sources: the urine of post-menopausal women (Humegon,
Repronex, Pergonal) and through recombinant DNA technology
(Gonal-F and Follistim). Injectable FSH medication is started
on the third day of a menstrual period and is continued
for approximately ten days. We carefully monitor the ovarian
response of each patient and individualize therapy. Serial
transvaginal ultrasounds
evaluate follicular growth. Measurement of estradiol
and progesterone
reflect ovarian response, and lead to FSH dose modifications
as needed. Most patients are seen in the office every two
to three days during the course of therapy. Intrauterine
inseminations are frequently used in conjunction with
injectable gonadotropins. Pregnancy rates with injectable
FSH and intrauterine inseminations are as high as 20% per
cycle. Patients with unexplained infertility
and endometriosis
have very favorable prognoses. Most couples undergo two
to six cycles of injectable FSH therapy prior to moving
onto in
vitro fertilization.
The majority of pregnancies from FSH therapy are single
babies (65%). Twins occur in approximately 25% of pregnancy
cycles. Multiple gestations including triplets, quadruplets
and quintuplets are not common with injectable gonadotropins,
but they do occur (<5%). We carefully monitor ovarian
response in an attempt to maximize the likelihood of establishing
a pregnancy while minimizing the chance of multiple gestations.
If many ovarian follicles (and subsequently many eggs) are
being developed, you will be informed of that fact so you
can make a conscious decision whether or not to trigger
ovulation,
with the subsequent risk of multiple gestations. Ectopic
pregnancies occur in approximately 0.7% of all spontaneous
conceptions and 2% of FSH treated cycles.
Women using injectable FSH medications can develop ovarian
hyperstimulation syndrome (OHSS). OHSS usually occurs seven
to ten days after ovulation. It is characterized by mild
to moderate ovarian enlargement, weight gain and abdominal
bloating. Rarely, an ovary can twist (torse) with acute
onset of pelvic pain, nausea and vomiting. In severe cases
of OHSS, blood clotting abnormalities, electrolyte imbalances,
and the accumulation of large amounts of fluid in the abdomen
can occur. Fortunately, most women with ovarian hyperstimulation
syndrome have a very mild form of the disorder requiring
nothing more than diminished activities and maintaining
good oral intake. Rarely, fluid is drained from the abdomen,
with prompt OHSS resolution. We rarely have one significant
case of ovarian hyperstimulation syndrome annually.
The risk of ovarian cancer resulting from injectable FSH
medications is completely unknown. Ongoing studies are under
way through the National Institutes of Health. Those results
should be available in several years' time. At the present
there is little evidence to support an association between
the use of injectable FSH medications and ovarian cancer.
