Superovulation Risks and Success

Hand on woman's abdomen, feeling bloated and sensitive due to superovulation

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Superovulation is a term used to describe the drug-induced release of multiple eggs for use in assisted reproductive technologies such as in vitro fertilization (IVF). Normally, only one egg is ovulated per cycle but with the use of fertility drugs, a person with ovaries might be able to produce several eggs, which can then be retrieved from the ovaries prior to ovulation.

Superovulation comes with several risks, including multiple pregnancies (such as twins or triplets), ovarian hyperstimulation syndrome, and ovarian torsion. There are also potential risks and side effects related to what kind of treatment is being used, as well as risks associated with the fertility drugs chosen.

Fertility Drugs

Superovulation or controlled ovarian hyperstimulation should not be confused with ovulation induction. During ovulation induction, Clomid (clomiphene) is commonly used for induction with the goal that the ovaries will produce and release a healthy egg.

Superovulation, on the other hand, is used when more than one egg is desired. Sometimes, superovulation is used during intrauterine insemination (IUI) treatment. However, because of the risk of multiple pregnancies, IUI treatment typically involves ovulation induction. Overall, there are two goals of superovulation:

  • Induce the ovaries into maturing many eggs
  • Prevent the ovaries from releasing those eggs prematurely

If the eggs ovulate on their own, they will be released from the ovaries and become lost. For IVF, your doctor needs to be able to retrieve them directly from the ovaries. If you ovulate before the egg retrieval, it would lead to your IVF cycle being canceled.

To stimulate superovulation, injectable fertility drugs called gonadotropins are used. To prevent premature ovulation, either a GnRH agonist or GnRH antagonist is used.

Are Clomid or Letrozole Used?

Clomid and Femara (letrozole) are rarely used for superovulation. These fertility drugs are more commonly used for ovulation induction—when you want just one or two eggs at most. While it is possible to have an IVF cycle using clomid or letrozole, it would more closely resemble what’s known as a “natural cycle.”

A natural IVF cycle is when IVF is performed without overstimulating the ovaries. As a result, only one or two eggs are retrieved. With natural IVF cycles, the live birth rates are lower. However, there are times when it’s the right treatment option.

How Many Eggs Are the Goal?

The number of eggs you want to mature will depend on your diagnosis and plan for your treatment. The “ideal” number of eggs retrieved will depend on your family planning goals as well as your doctor’s professional opinion and experience.

Don’t be afraid to ask what the goals are. During the ultrasound monitoring of an IVF cycle, your doctor will measure and count how many follicles are growing in the ovaries. Inside the follicles are oocytes, or eggs.

Not every follicle will give you an egg, and not every egg will become an embryo. Furthermore, not every embryo will be hearty and healthy enough to be transferred.

For example, you might have 10 follicles but only get seven or eight eggs. Perhaps four or six of those seven or eight eggs fertilize, and just one or two fertilized eggs might be healthy enough to be transferred.

To increase your odds of pregnancy success, you want to produce several eggs. In general, most doctors hope to retrieve at least 10 eggs from your ovaries in a typical IVF cycle. Between eight and 15 eggs is generally considered a good number.

If you produce four or fewer follicles, your doctor may cancel your IVF cycle because your odds for pregnancy success are low with four or fewer eggs. Although disappointing, canceling your IVF cycle helps you avoid IVF-related risks and costs when there would be little benefit.

Your doctor also might cancel your cycle if you produce too many follicles (more than 20). When this occurs, your risk of ovarian hyperstimulation is high.

However, in some cases, it might be possible to mitigate the risk and proceed with the cycle. For example, your doctor might retrieve the eggs but not do an embryo transfer. They can freeze any healthy embryos and transfer them after your ovaries recover.

If you’re having mini or micro-IVF, the goal might be to produce just four or five follicles. While fewer than five follicles during full IVF may be considered a bad sign, it can be ideal for mini-IVF.

Most doctors aim for just one or two eggs for an IUI cycle. If you’re having an IUI cycle with superovulation, having no more than four follicles is best. Remember that if you ovulate four eggs, there is a possibility you could conceive quadruplets.

What Are the Success Rates?

Success rates will depend on what kind of treatment is being used (IVF, IUI, or mini-IVF), your diagnosis, and your age. Generally, IVF success rates are better than IUI rates. But, you wouldn’t want to use a more invasive, expensive fertility treatment if you don’t need to.

Superovulation might not be successful in women over age 40 and women diagnosed with primary ovarian insufficiency (also known as POI or premature ovarian failure).

However, this doesn’t mean IVF can’t help you conceive. You might need to see a specialist with specific experience or consider using an egg donor. In fact, IVF success rates with an egg donor are good.

Ideally, your doctor won't want to put you through IVF or superovulation if they don't think it will work for you. This is why ovarian reserve testing is done. Ovarian reserve testing is intended to predict how you will respond to fertility drugs during IVF.

Another test called the Clomid challenge test (CCT) is also used at times to predict potential superovulation success. Be sure to talk to your doctor about whether or not they think this will be a successful route.

6 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Additional Reading

By Rachel Gurevich, RN
Rachel Gurevich is a fertility advocate, author, and recipient of The Hope Award for Achievement, from Resolve: The National Infertility Association. She is a professional member of the Association of Health Care Journalists and has been writing about women’s health since 2001. Rachel uses her own experiences with infertility to write compassionate, practical, and supportive articles.