By Zaira Salvador BSc, MSc (embryologist), Mark P. Trolice MD, FACOG, FACS, FACE (reproductive endocrinologist), Susana Cortés Gallego BSc, PhD (senior embryologist) and Aitziber Domingo Bilbao BSc, MSc (embryologist).
Last Update: 09/21/2018

Intracytoplasmic Sperm Injection (ICSI) is the most commonly used type of In Vitro Fertilization (IVF) using the woman’s eggs after being retrieved from the ovaries by follicle puncture. Today, nearly 90% of IVF cycles are done using the ICSI technique.

It should be noted, however, that classical IVF is almost as successful as ICSI the first time. In fact, the odds of pregnancy depend on other factors, especially on age and egg quality, rather than on the technique used to fertilize the egg.

How to determine ICSI success

To determine the success of the ICSI technique, we can pay attention to several rates, including the pregnancy and the live birth rates. All in all, the ultimate goal is to achieve a successful pregnancy and to deliver a healthy baby.

Nowadays, the pregnancy rate per embryo transfer in ICSI cycles is about 37%, while the live birth rate is 25% approximately. In short, it means that one out of four ICSI cycles lead to the delivery of a healthy child.

If we evaluate the ICSI success rates by age, these figures can vary greatly, given that a woman’s ovarian reserve and the quality of the eggs she releases diminish with age.

Factors that influence the odds of success

ICSI is the preferred technique for most embryologists because of the number of advantages that if offers in comparison with classical IVF. However, one should keep in mind that there exist a series of factors that can affect the outcomes of ICSI:

Some experts have a different opinion as regards the pros of ICSI, considering that standard IVF procedures can reach higher success rates in older women, such as the possibility of creating embryos with a reduced number of chromosomal abnormalities.

In spite of that, a general overview of the results of ICSI over the years has shown that the likelihood of developing a genetic disease in children born by ICSI is similar to that of naturally conceived children.

Want to learn more about the pros and cons of both techniques? Check this out: ICSI Success Rates Compared to IVF Treatment – Which Is Better?

Success rates by age

As mentioned earlier, age is a key factor when it comes to determining the success rates of ICSI procedures. We have split the success rates per cycle into three age groups, as one shall see in the following sections.

Pregnancy rate

Even though the ICSI fertilization rate is 70-85% on average, it should be reminded that fertilization does not translate into a successful pregnancy. The risk of early embryo arrest or miscarriage exists and should be considered when determining the pregnancy success rates of IVF/ICSI.

Taking into account the percentage of positive pregnancy tests obtained per IVF transfer, the success rates of IVF with ICSI by age can be classified into:

Women aged <35 years
Success rates of ICSI the first time can be as high as 32%, and can increase to up to 49% in subsequent cycles (cumulative rate) with Frozen Embryo Transfer (FET).
Women aged 35-39 years
The pregnancy rate drops to 26% on the first attempt, and the cumulative rate can reach up to 37%.
Women aged ≥40 years
The pregnancy success rate is nearly 23% the first time, with a cumulative rate of 20% in subsequent FET cycles.

Indeed, as one can see, age is the most challenging factor for female patients considering IVF/ICSI treatment, to the point that it determines whether the treatment will be successful or not.

Live birth rate

The live birth rate refers to the number of healthy children born after an IVF/ICSI cycle, which is the ultimate goal of every infertility treatment. The success rates by age can be described as follows:

Women aged <35 years
24 percent chance of a live birth per cycle.
Women aged 35-39 years
18 percent chance of a live birth per cycle.
Women aged ≥40 years
7 percent chance of a live birth per cycle.

The live birth rates, as one can see by comparing both graphs, are lower if compared to the pregnancy success rates. Unfortunately, a percentage of ICSI cycles end up in miscarriage.

If you need to undergo IVF to become a mother, we recommend that you use "The Calculator". In 3 simple steps, it will show you a list of clinics that fit your preferences and meet our strict quality criteria. Moreover, you will receive a report via email with useful tips to visit a fertility clinic for the first time.

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FAQs from users

What are the success rates of ICSI? What about IVF?

By Mark P. Trolice MD, FACOG, FACS, FACE (reproductive endocrinologist).

Fortunately, multiple studies have demonstrated fertilization and pregnancy success rates with ICSI are equivalent to standard insemination by IVF.

In which cases is ICSI used automatically?

By Susana Cortés Gallego BSc, PhD (senior embryologist).

ICSI or Intracytoplasmic Sperm Injection is a type of In Vitro Fertilization that is used to fertilize the egg cell. With ICSI, the sperm cell is selected and injected within each one of the eggs collected.

Unanimously recognized indications of ICSI include:

  • Severe male infertility: a single sperm per egg cell is enough
  • Previous fertilization failure using conventional IVF
  • Issues with the oocytes: poor-quality eggs may compromise sperm penetration into the egg cell
  • Techniques that involve isolating the egg from the cells that surround it (egg donation, preimplantation diagnosis…)

What are the advantages and disadvantages of ICSI over IVF?

By Aitziber Domingo Bilbao BSc, MSc (embryologist).

Both techniques are reproductive technologies, and as such, we cannot say that one is better than the other. Actually, it depends on the diagnosis of each couple. In the case of conventional IVF, we put the oocyte in contact with a determined concentration of sperm, so that the sperm itself fertilizes the egg, which resembles natural fertilization to a large extent. In many cases, sperm quality is altered, in which case using the sperm won’t be possible. In such situations, we use ICSI. It consists in microinjecting the sperm, which is subjectively selected by the embryologists, into the oocyte.

Does ICSI increase chances of twins?

By Zaira Salvador BSc, MSc (embryologist).

Yes, there’s an increased chance of becoming pregnant with multiples as in classical IVF procedures. To be precise, the risk of a twin pregnancy with ICSI is about 30-35%, and a 5-10% chance for having triplets or more.

What are the success rates of ICSI the first time?

By Zaira Salvador BSc, MSc (embryologist).

The success of a fertility treatment using ICSI depends on several factors, but especially on maternal age. So you can have an idea, a woman whose ovarian reserve is not severely affected and is able to obtain at least 8 viable eggs in one cycle can reach a pregnancy rate of 37% per embryo transfer, and a live birth rate of 25% following the first attempt.

What are the ICSI success rates with male factor?

By Zaira Salvador BSc, MSc (embryologist).

In depends on the cause of male infertility. For example, severe male factors such as azoospermia require a testicular biopsy to obtain viable sperms.

The odds of success of ICSI depend on the expertise of the embryologist to select the most viable live sperm out of the ones retrieved from the testis, with good motility and morphology. If sperms with this characteristics were found, the success rates will be similar to those of a cycle with non-affected sperm. The success rates are 22% approximately.

What are the ICSI success rates with PCOS?

By Zaira Salvador BSc, MSc (embryologist).

The majority of women are able to get pregnant with ICSI in spite of having PCOS (Polycystic Ovary Syndrome), provided that they are not older than 40 years of age. With ICSI, the success rates can be as high as 60%.

What is the IVF/ICSI success rate with PGD?

By Zaira Salvador BSc, MSc (embryologist).

Oftentimes, Preimplantation Genetic Diagnosis (PGD) compromises embryo development, which translates into lower success rates. In these cases, the live birth rate of ICSI with PGD is about 14%.

Suggested for you

The ovarian reserve is an indicator of the egg supply of a woman at a particular stage of her reproductive age. Want to learn more about its relationship to female fertility and how to measure it? Check this out: What Is the Ovarian Reserve?

The number of eggs retrieved after ovarian stimulation influences the success of ICSI. To learn more about the recommended number of eggs to be obtained for IVF, click here: What Is a Good Number of Eggs Retrieved for IVF?

You can learn more about the reasons why a couple may need ICSI treatment by visiting the following post: When Is ICSI Recommended?

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References

Aytoz A., Camus M., Tournaye H., Bonduelle M., Van Steirteghem A. and Devroey P. (1998): Outcome of pregnancies after intracytoplasmic sperm injection and the effect of sperm origin and quality on this outcome. Fertil. Steril. 70: 500-505.

ESHRE Capri Workshop Group. Intracytoplasmic sperm injection (ICSI) in 2006 (2007): evidence and evolution. Hum Reprod Update;13:515 – 526.

Fernández A, Castilla JA, Martínez L, Núñez AI, García-Peña ML, Mendoza JL, Blanco M, Maldonado V, Fontes J, Mendoza N (2002). Indicadores de calidad asistencial en un programa de FIV/ICSI. Rev Iberoam Fertil; 19: 249-52.

Mantikou E, Youssef MA, van Wely M, van der Veen F, Al-Inany HG, Repping S, et al. Embryo culture media and IVF/ICSI success rates: a systematic review. Hum Reprod Update 2013;19:210–20.

Palermo C.D. Cohen J. Rosenwaks Z (1996). Intracytoplasmic sperm injection: a powerful tool overcome fertilization failure. Fertil Steril 6: 899-908.

Palermo C.D., Joris H. Devroey P. Van Steirteghem A.C. (1992). Pregnancies after intracytoplasmic injection of single spermatozoa into an oocyte. Lancet, 340.

Pandian Z, Marjoribanks J, Ozturk O, Serour G, Bhattacharya S: Number of embryos for transfer following in vitro fertilisation or intra-cytoplasmic sperm injection. Cochrane Database Syst Rev 2013, 7:CD003416.

Sociedad Española de la Fertilidad (SEF). Fecundación in vitro o microinyección espermática (FIV/ICSI), y criopreservación de embriones. Documento informativo.

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Authors and contributors

 Zaira Salvador
BSc, MSc
Embryologist
Bachelor's Degree in Biotechnology from the Polytechnic University of Valencia (UPV). Embryologist specializing in Assisted Procreation, with a Master's Degree in Biotechnology of Human Assisted Reproduction from the University of Valencia (UV) and the Valencian Infertility Institute (IVI). More information
License: 3185-CV
 Mark P. Trolice
MD, FACOG, FACS, FACE
Reproductive Endocrinologist
Mark P. Trolice is the Director of Fertility CARE – The IVF Center and Clinical Associate Professor in the Department of Obstetrics & Gynecology (OB/GYN) at the University of Central Florida College of Medicine. He is Board-certified in REI and OB/GYN, and maintains annual recertification. His colleagues select him as Top Doctor in America® annually, one among the top 5% of doctors in the U.S. More information
License: ME 78893
 Susana Cortés Gallego
BSc, PhD
Senior Embryologist
Bachelor's Degree in Biological Sciences from the Complutense University of Madrid, and PhD in Comparative Animal Physiology from the Faculty of Biological Sciences. Extensive experience in the scientific field, and currently working as the coordinator of the laboratories of Clínica Tambre in Madrid, Spain. More information
License: 17980-M
 Aitziber Domingo Bilbao
BSc, MSc
Embryologist
Bachelor's Degree in Biology from the University of the Basque Country. Master's Degree in Human Assisted Reproduction from the Complutense University of Madrid, and Master's Degree in Biomedical Research from the University of the Basque Country. Wide experience as an Embryologist specialized in Assisted Procreation. More information