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Inducing Ovulation Overview
There
are two primary hormones which control ovary follicle
development and ovulation in women, they are: FSH (follicule-stimulating
hormone) and LH (lutenizing hormone). Women with normal
ovarian function ovulate sometime during the middle of each
menstrual cycle. In the beginning of a woman’s cycle, her
brain releases FSH which triggers the ovaries to develop
multiple follicles each containing an egg. As the follicles
mature, one follicle quickly dominates the others and
inhibits them from any further development. Once the
dominant follicle has fully matured it sends a message to
the brain to release LH. The release of LH triggers the
dominant follicle to release its egg which then begins the
egg’s journey into the uterus. If the body does not produce
these hormones in exactly the right way, a hormonal
imbalance or deficiency can cause infertility in women.
Treatment with Gonadotropins or "fertility drugs" can
increase the likelihood of conception by stimulating
inactive ovaries to ovulate or produce more than one egg at
a time.
This article discusses the following topics:
- Candidates
- Developing follicles
- Triggering egg release
- Treating anovulation from PCOS or pituitary dysfunction
- Women who don't ovulate on their own or couples who have other or unknown reasons for infertility.
- Women using assisted reproductive technologies, such as in vitro fertilization (IVF).
If you do not ovulate naturally, the aim is to produce only one egg. Thus, the amount of medicine you use (and the risk of side effects) is usually much lower than for couples with other fertility issues. Low body fat can prevent ovulation. If you are underweight, improve your nutrition and increase your body fat before using these medicines. Overweight women can benefit from weight loss. Cross reference "Can Weight affect my fertility".
Several medicines can artificially trigger (and sustain) the development of follicles. Your doctor may recommend any of these medicines to increase the likelihood of ovulation or the number of follicles that mature. The medicines are usually taken during the early part of the monthly cycle. All of these medicines can cause mood swings and increase your risk of an ovarian cyst or a multiple pregnancy (twins, triplets, or more).
Infrequently, they can cause ovarian hyperstimulation, a painful condition that may require hospitalization. Some studies suggest that they may increase the risk of ovarian cancer, although other studies refute those findings. Your doctor should monitor your progress with ultrasound and, for the injectable drugs, blood tests of estrogen levels.
A. Clomiphene citrate: Clomid®, Serophene®
Clomiphene citrate is often the first drug used in fertility treatments. It's relatively inexpensive and is available in pill form. Candidates include women who do not ovulate and couples with unexplained infertility. It is unlikely to help couples if both fallopian tubes are blocked or damaged.
Most patients take clomiphene for five days early in the cycle. (Dosage usually starts at 50 mg and may be increased in later cycles up to 200 mg.) Clomiphene tricks the brain into thinking that the ovaries aren't responding. Your brain increases the production of FSH to stimulate the ovaries to work harder.
If you don't naturally ovulate, the aim is to induce one follicle to develop. If you have other causes of infertility, a good response is two or three mature follicles. If too many follicles mature, the cycle may be cancelled to prevent high-order multiples (triplets or more), which occur in less than 1 percent of clomiphene cycles. Clomiphene can be used with intercourse or with intrauterine insemination.
Clomiphene has two side effects that may lower your fertility: it sometimes decreases the amount of mucus produced from the cervix, and it can decrease the thickness of the uterine lining. Couples that will be successful with clomiphene therapy usually achieve pregnancy within the first three months of use.
CLICK HERE for more information about Clomiphene Citrate (Clomid®)
B. Injectable medicines
Injectable hormones may be useful if you do not respond to clomiphene. When used for anovulatory women, a good response is one or two mature follicles. When used in combination with intrauterine insemination for women who ovulate, the aim is three to five follicles.
These hormones are also used to produce larger numbers of mature eggs for assisted reproductive technologies, such as IVF. When used with egg retrieval, eight to 20 mature follicles are desirable. The eggs are removed before ovulation, and any extra embryos can be frozen.
Daily ultrasound and blood tests allow your doctor to monitor your progress and help prevent complications.
CLICK HERE for more information about injectable medications used to induce ovulation.
Human menopausal gonadotropin (hMG): Repronex®, Pergonal®, Humegon®
Human menopausal gonadotropin (hMG) is a natural hormone retrieved from the urine of menopausal women. hMG contains both FSH and LH. It was traditionally delivered as an intramuscular injection. In some cases, your doctor may recommend a subcutaneous injection using a shorter needle that goes just below the surface of the skin.
These drugs are often used in combination with intrauterine insemination to improve pregnancy rates. If you aren't successful within three to four cycles, your doctor may recommend moving on to IVF. hMG is sometimes used in IVF cycles, but most clinics now prescribe pure FSH.
CLICK HERE for more information about injectable medications used to induce ovulation.
Follicule Stimulating Hormone (FSH): Gonal-F®, Follistim®, Bravelle®
Gonal-F® and Follistim® are created through bioengineering, Bravelle® is a purified urinary extract. Pure FSH is used to induce ovulation for IVF and other assisted reproductive technologies. Some believe it produces higher numbers of (and better quality) eggs than hMG. Some fertility programs prescribe FSH combined with a small amount of hMG.
FSH is less irritating than hMG and can be given as a subcutaneous injection. You inject the drugs for eight to 14 days. The duration and dosage depend on follicle development and other personal factors.
CLICK HERE for more information about injectable medications used to induce ovulation.
In a natural cycle, the body produces a surge of luteinizing hormone (LH) when an egg is mature. This LH surge triggers the follicle to release the egg. In treatment cycles, the LH surge generally doesn't occur. An injection of human chorionic gonadotropin (hCG; Profasi®, Pregnyl®, Novarel®, Ovudrel®) triggers the release.
The hCG can also control the timing of the egg release - so your doctor can schedule artificial insemination or egg retrieval. About 40 hours after the hCG injection, any follicle of a certain size or larger will release its egg. Ovulation is complete.
Side effects include cramping or hyperstimulation. Since pregnancy tests work by detecting hCG in blood or urine, you may have a false positive result if you test within 12 days of an hCG injection.
Your doctor will tell you when to inject the hCG. In some fertility treatments, you'll take a GnRH antagonist such as Lupron®, Synarel®, Antagon®, or Cetrotide® to prevent the natural LH surge from occurring. In clomiphene cycles, you may use an ovulation predictor kit to keep track of LH level.
CLICK HERE for more information about GnRH antagonists.
Treating anovulation from PCOS or pituitary dysfunction
Some women don't ovulate because of a condition called polycystic ovary syndrome (PCOS) or a problem with pituitary function. By treating the underlying condition, these women may ovulate naturally.
If you have PCOS, your doctor may prescribe an antidiabetes drug, such as Glucophage® or Actos®. The drugs work best for women who are overweight or have signs of insulin intolerance, common symptoms of PCOS. The drugs help the body use glucose more efficiently and may allow natural ovulation. If you have a pituitary dysfunction that results in high levels of prolactin, your doctor may prescribe Parlodel®. Prolactin inhibits ovulation. Parlodel lowers prolactin levels to allow ovulation. Cabergoline is an alternative drug.
These oral medicines should be used until you become pregnant. They don't require the constant monitoring of other fertility medicines. Use Basal Body Temperature (waking temperature) analysis to see whether you ovulate. If you don't ovulate within a few months, your doctor may add treatment with hormones, such as Clomid, HMG, or FSH.
CLICK HERE for more information about PCOS
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