What Is Superovulation? And What Does It Involve?

Fertility Drugs Used + Risks and Odds of Success + How Many Eggs Are Ideal

Hand on woman's abdomen, feeling bloated and sensitive due to superovulation
Superovulation can cause bloating and abdominal cramps. Let your doctor know if bloating is severe, worsening, or if you're in pain. Laurence Monneret / The Image Bank / Getty Images

Quick definition: Superovulation is a term used to describe the drug-induced production of multiple eggs for use during assisted reproductive technologies such as in vitro fertilization (IVF).

Normally, a woman ovulates just one egg per cycle. With the use of fertility drugs, she may be able to produce several eggs, which can then be retrieved from the ovaries prior to ovulation.

Superovulation shouldn’t be confused with ovulation induction.

Clomid is a commonly used ovulation induction medication.

During ovulation induction, the goal is for the ovaries to mature only one or two eggs. With superovulation, more than two eggs are desired.

Superovulation is also sometimes used during IUI treatment. However, due to the risks of a multiple pregnancy, IUI treatment typically involves ovulation induction.

Risks of superovulation include ovarian hyperstimulation syndrome, ovarian torsion, and multiple (twins, triples, etc.) pregnancy.

There are also potential risks and side effects related to what kind of treatment is being used (IVF or IUI), as well as risks to the fertility drugs chosen. (More on this below.)

Fertility Drugs Used During Superovulation

There are two goals when it comes to 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 become lost in the abdominal cavity.

For IVF, your doctor needs to be able to retrieve them directly from the ovaries. Ovulating before the egg retrieval would lead to your IVF cycle being canceled.

To stimulate superovulation, injectable fertility drugs known as gonadotropins are used:

    To prevent premature ovulation, either a GnRH agonist or GnRH antagonist is used:

    Are Clomid or Letrozole Used for Superovulation?

    Clomid and letrozole are rarely used for superovulation. These fertility drugs are chosen more commonly 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 overstimulation of the ovaries. Just one or two eggs are retrieved.

    The live birth rates are lower with natural IVF cycles, though there are times when it’s the right treatment option.

    How Many Eggs Are the Goal in Superovulation? What Are Too Few? Too Many?

    The number of eggs you want to ideally mature will depend on your diagnosis and treatment plan.

    The “ideal” number of eggs retrieved will also depend on your doctor’s professional opinion and experience.

    Don’t be afraid to ask.

    During 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.

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

    For example, you may have 10 follicles, but only get 7 or 8 eggs. From those 7 or 8 eggs, only four or six may fertilize, and only two or three may be healthy enough to be transferred.

    This is why you want to produce several eggs, to increase your odds of pregnancy success.

    Generally speaking, for a typical IVF cycle, your doctor hopes to retrieve at least 10 eggs from your ovaries.  Anywhere between 8 and 15 eggs may be considered a good number.

    If you produce four or fewer follicles, your doctor may cancel your IVF cycle.

    (The reason is that your odds for pregnancy success are low with four or fewer eggs. They want to avoid putting you at risk and increasing your financial cost, with little benefit.)

    If you produce too many follicles – like more than 20 – it’s also possible your doctor may cancel the cycle. This is because your risk of ovarian hyperstimulation is high.

    (There are ways to mitigate the risk and proceed with the cycle, in some cases. For example, they may retrieve the eggs but not do an embryo transfer. They may freeze any healthy embryos and plan to transfer them after your ovaries recover. Talk to your doctor about your specific situation.)

    If you’re having mini or micro-IVF, the goal may be to produce just four or five follicles.

    While fewer than five follicles during full IVF may be considered a bad sign, during mini-IVF, this can be ideal.

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

    What Are the Success Rates for Superovulation?

    Success rates will depend on what kind of treatment is being used (IVF, IUI, 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.

    For women over age 40 and women diagnosed with primary ovarian insufficiency (also known as POI or premature ovarian failure), superovulation may not be successful.

    That doesn’t mean IVF can’t help you conceive. You may need a specialist with experience in these cases. Or, you may need to consider using an egg donor. IVF success rates with an egg donor are really good.

    Ideally, your doctor wouldn’t want to put you through IVF or superovulation if they didn’t think it’ll work for you. This is why ovarian reserve testing is done.

    Ovarian reserve testing is intended to predict who will not respond as well to fertility drugs during IVF.

    Another test some doctors do to predict potential superovulation success is known as the Clomid challenge.

    Learn more about fertility drugs and treatment:


    Ovarian Stimulation for IVF in Low Responders. Advanced Fertility Centers of Chicago. Accessed February 2, 2016. http://www.advancedfertility.com/ivf-low-response.htm

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