Review
Material
Estrous
cycle
Menstrual cycle
Prostaglandins
Progestins
Ovulation Induction
Human Infertility
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Human
Infertility
Ovulation induction medications,
often referred to as fertility drugs, are used to stimulate the follicles
resulting in the ovulation of one or more oocytes in one cycle.
Protocals control
the time of ovulation by administering hCG, so sexual intercourse, intrauterine
inseminations, artificial inseminations and in vitro fertilization procedures
can be scheduled at the most likely time to achieve pregnancy.
Superovulation is
achieved by the dose of the drug given. Ovarian response is monitored
with ultrasonography.
The most commonly
used drugs are:
Drug |
Effect |
Clomiphene
Citrate |
(Clomid,
Serophone) Orally active, synthetic, anti-estrogen. Binds to estrogen
receptors on the hypothalmus, reducing the negative feedback from
in vivo estrogens so that GnRH is increased leading to increased FSH
and LH. Ovulation occurs via normal events. Multiple pregnancy rate
is 5% and predominantly twins. |
Gonadotropins |
|
Menotropins |
(Perganol, Repronex,
Follistim, Bravelle and GonalF) Human menopausal gonadotropin (hMG), activity is like a 1:1 combination of LH and FSH. It is administered for 7-12 days
to stimulate follicular growth and maturation. |
hFSH |
Human recombinant FSH. It only has FSH activity. Used
to stimulate follicular growth and development. |
hCG |
(Profasi,
Serono; Pregnyl, Organon; Novarel, Ferring; A.P.L., Wyeth-Ayerst)
Behaves like luteinizing hormone (LH) to cause ovulation of follicles.
Ovulation occurs 36-48 h after administration. |
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