IVF failure occurs when your IVF cycle ends without a pregnancy or live birth. You may not have enough viable eggs or embryos to continue the process, your embryo transfer may fail, or your fertility care team may decide that it is not safe for your body to continue with your cycle. However, IVF failure does not necessarily signal the end of your fertility journey.

Six Second Snapshot

• IVF failure occurs when there are not enough eggs or embryos to continue the process, your embryo transfer fails, or your fertility care team decides that it is not safe for your body to continue with your cycle.
• According to the CDC’s data for 2020, even for patients under 35, only 51.1% of assisted reproductive technology (ART) cycles resulted in a live birth (1).
• It’s very difficult to start IVF and not get pregnant after so much effort. Knowing why IVF can fail can help set expectations and inform your conversations with your clinician.

Causes for IVF Failure at Each Step of the IVF Process

In vitro fertilization (IVF) is not a single procedure but a series of complex procedures designed to produce multiple eggs and embryos, each of which is a chance at pregnancy. However, not every follicle will become an egg, not every egg will fertilize and grow into an embryo, and not every embryo will implant. This attrition is sometimes referred to as the “IVF Funnel.”

In other words, because IVF treatment is not a single procedure but a series of complex procedures, there are many points in the process when your IVF cycle may end without a pregnancy or live birth. When this happens, it’s often referred to as IVF cycle cancellation or IVF failure. It’s possible that you may not have enough viable eggs or embryos to continue the process. Another reason for failed IVF is that your fertility care team may decide that it is not safe for your body to continue with your cycle. Below, we’ll outline the points during the IVF process at which this decision may occur, and what your options are if that happens.

Problems with Ovarian Reserve or Hormone Medications

IVF begins with ovarian stimulation, when the ovaries are stimulated with hormone medications to produce more eggs than normal during a menstrual cycle. Your reproductive endocrinologist (RE) may decide to cancel your cycle (meaning that egg retrieval doesn’t occur) during ovarian stimulation because of:

• Poor ovarian response - If your ovaries are not responding well to the hormone medications, they can’t produce enough egg-containing follicles to continue with the IVF process.
• Risk of severe ovarian hyperstimulation syndrome (OHSS) - OHSS occurs when the ovaries over-respond to the hormone medications used during IVF. Your RE will likely be able to predict your chance of developing OHSS through your baseline test results before you begin IVF, and can adjust your medications accordingly. Additionally, most cases of OHSS can be treated at home. However, severe OHSS can result in hospitalization and death. If your RE suspects that you are at risk of severe OHSS, they may end your IVF cycle before egg retrieval.
• Illness - Ovarian stimulation requires regular medication injections and frequent trips to the clinic for bloodwork and ultrasounds to check on your hormone levels and follicular growth. If you become ill during ovarian stimulation, such as with Covid or the flu, there’s a chance that your doctor will cancel your cycle. This may be because you are too ill to continue with the medications, or because there’s too high a risk that you will get your fertility care team ill, as well.

Issues with Egg Retrieval

In some cases, IVF failure occurs during or after egg retrieval. This can happen for a number of reasons:

• Premature ovulation - During ovarian stimulation, one of the hormone medications you will take will suppress ovulation. Once you have enough follicles that are a good size for retrieval, your doctor will schedule a trigger shot which will encourage your eggs to mature (meaning that they shed half their chromosomes). Your egg retrieval procedure will be scheduled for about 34-36 hours after your trigger shot. The timing of these medications and procedures has to be very precise in order to control ovulation. If you miss the window for retrieval, your eggs will release from your ovaries and cannot be captured.
• Not enough mature eggs - After your RE retrieves your eggs (sometimes referred to as “oocytes”) from your ovaries, the embryologist will look at each egg to ensure that they are mature and that egg quality is high enough to continue with the IVF process. However, it’s possible that none of your eggs will be mature or of a high enough quality to fertilize. This may happen if you have diminished ovarian reserve before starting IVF, in which case you might have fewer eggs to retrieve.

Fertilization Problems

Though you may have mature eggs after retrieval, it’s possible that they may not fertilize. Some reasons for this include:

• Quality or quantity of eggs - Issues with quality or quantity of eggs may mean that none of them fertilize.
• Male factor infertility - Fertilization during IVF occurs in a petri dish, in which the eggs and sperm are placed in a dish together. It’s possible that the sperm do not fertilize the eggs in this environment, in which case your IVF cycle ends. If your fertility care team anticipates an issue with fertilization, they may choose to try intracytoplasmic sperm injection (ICSI) during your next cycle, in which the embryologist injects each egg with sperm to fertilize them. However, it’s important to note that ICSI can also result in lack of fertilization.

Insufficient Embryo Growth

After fertilization, your embryos will grow in culture in the lab for 3-7 days. Usually, fresh embryo transfer occurs after the embryo has grown for about 3-5 days. If you are doing a frozen embryo transfer, your embryologist will likely wait until the embryos have reached the blastocyst stage (which usually occurs on day 5-7) to assess them for quality (also known as “embryo grading”) and select embryos for transfer. However, it’s possible that none of your embryos will grow sufficiently to transfer or freeze.

Chromosomal or Genetic Abnormalities

If you are concerned about chromosomal or genetic abnormalities, which can cause miscarriage or lifelong disability for your child, you may choose to do Preimplantation Genetic Testing (PGT) on your embryos. Your embryologist will take a small section of cells from the outer layer of the blastocyst stage embryo to conduct these tests. It is possible that your test results may show that none of your embryos were chromosomally or genetically normal, in which case you may choose to end your IVF cycle.

Failed Embryo Transfer

If you have embryos to transfer, your RE will likely transfer one at a time. IVF failure may still occur at this stage if the embryo does not implant, or if you miscarry. Some reasons for failed embryo transfer include:

• Endometrial receptivity - The lining of the uterus (also known as the uterine lining or endometrium) renews each menstrual cycle in order to create an ideal environment for an embryo to implant. However, if there’s an issue with the endometrium - for example, if it is too thin - implantation can’t occur.
• Chromosomal abnormality - If you choose not to do PGT testing, there’s a chance that a chromosomal abnormality in the embryo can affect implantation or cause a miscarriage.
• Anatomic Causes - It’s possible that an issue with your uterus, such as intrauterine adhesions (scar tissue in the uterus) or septate uterus (a uterus with two chambers instead of one), could be causing implantation failure (2). If this is the case, your clinician may suggest treatment before trying IVF again.
• Thrombophilia - Patients with this clotting disorder have a much higher risk of implantation failure (3).

What can be particularly difficult is that failed implantation symptoms can be similar to the symptoms of implantation success: breast tenderness, cramping, headaches, and bloating. This is because you will likely be supplementing with the hormone progesterone, which helps support an early pregnancy, and progesterone can cause those symptoms as well. Because of this, it’s important to wait for your pregnancy test before assessing the success of your embryo transfer.

How Common Is It for IVF to Fail?

If you’ve experienced IVF failure, you’re not at all alone. According to the Centers for Disease Control and Prevention’s (CDC) data for 2020, even for patients under 35, only 51.1% of assisted reproductive technology (ART) cycles resulted in a live birth (1). The chance that an IVF cycle will fail increases with age, since age increases the likelihood of diminished ovarian reserve and of aneuploid (chromosomally abnormal) embryos. Below is a chart from the CDC that shows which percentage of intended egg retrievals in the US in 2020 (in other words, among IVF cycles that were started) resulted in a live birth, by age.

Multiple IVF cycles are often necessary before a live birth. Because success rates decrease with age, this is especially true for patients above 35.

Another way to look at this data is to view the average number of intended egg retrievals necessary by age group before the patient had a live birth:

As you can see, on average, patients need more than one egg retrieval before a live birth, and this number increases greatly after age 40.

It’s important to note that success rates are measured by the age of the patient at the time of egg retrieval. If you froze your eggs or embryos and transferred them several years later, you should assess your chance of success by your age when your eggs were retrieved. Along those lines, if you are using an egg donor, your success rates will be measured by the age of your egg donor when the eggs were retrieved.

It’s very difficult to start IVF and not get the much wanted outcome of a pregnancy after so much effort. Knowing some of the reasons why IVF fails can help set expectations and inform your conversations with your clinician. As you can see here, IVF failure can be a single step on your journey through infertility.