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.
Provided below is an index with the 7 points we are going to expand on in this article.
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 35%, while the live birth rate is 26% 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:
- Expertise of the specialist
- Conditions of the lab and the incubator
- Egg quality
- Egg maturation
- Age and ovarian reserve
- Sperm motility and morphology
- Chromosomal abnormalities in the eggs and/or sperm
- Uterine abnormalities, including endometriosis or uterine fibroids
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.
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
- se obtienen tasas de éxito del 43%.
- Women aged 35-39 years
- the success rate decreases to 34.8% of transfer-positive pregnancies.
- Women aged ≥40 years
- pregnancy rate of 22.5%.
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
- 34.6% percent chance of a live birth per cycle.
- Women aged 35-39 years
- 25.2% percent chance of a live birth per cycle.
- Women aged ≥40 years
- 12.8% percent chance of a live birth per cycle.
If you need to undergo IVF to become a mother, we recommend that you generate your Fertility Report now. 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.
FAQs from users
What factors influence the success rate of IVF-ICSI?
There are several factors that influence IVF success rates. Some of these are described below:
- is the most important factor for the success of IVF. Patients under 35 years old have the best prognosis. The success rates in women over 43 years are less than 5%..
- Antimullerian hormone (AMH)
- is not a direct factor but does affect the cumulative pregnancy rate. Having a lower AMH does not mean you have a lower success rate for a single IVF attempt. Having a high AMH makes it easier to have a higher cumulative pregnancy rate. The cumulative pregnancy rate is obtained after transferring all the frozen embryos that have been generated from an IVF cycle.
- Toxic substances
- patients who are smokers have a worse pregnancy rate than non-smoking patients.
- has been found to be a negative influence on the pregnancy rate.
Apart from these factors, there are numerous studies that indicate that patients following Mediterranean diet have a better outcome in IVF cycles. In addition, moderate exercise has also been shown to improve IVF results.
What is the IVF/ICSI success rate with PGD?
In the last Registry published by the Spanish Fertility Society (SEF Registry 2019), a clinical gestation rate by transfer of 52.2% is obtained. This success rate will vary depending on the indication for PGD, which can be due to advanced maternal age (the most frequent, 58.5% of the cycles initiated with PGD), molecular disease, cytogenetic disease, repeated miscarriages, implantation failure or others.
What are the success rates of ICSI the first time?
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 azoospermia?
With a severe male factor such as azoospermia, it will be necessary to perform a testicular biopsy to obtain spermatozoa.
The success of sperm microinjection depends on the embryologist's ability to select sperm that are alive in the biopsy and, if possible, with motility and good morphology. If sperm with these characteristics are found, the success rates are similar to those of a cycle with normal sperm recovery. According to SEF statistics for 2021, the probability of delivery by embryo transfer is 25.3%.
How successful is ICSI in an oocyte donation treatment?
The success rate of ICSI with donor eggs is much higher than in the previous cases. The advantage of ovodonation is that the success rate does not decrease with the age of the recipient patient, so that pregnancy rates per embryo transfer of about 55% are obtained.
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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FAQs from users: 'What factors influence the success rate of IVF-ICSI?', 'What is the IVF/ICSI success rate with PGD?', 'What are the success rates of ICSI the first time?', 'Does ICSI increase chances of twins?', 'What are the ICSI success rates with azoospermia?', 'What are the ICSI success rates with PCOS?' and 'How successful is ICSI in an oocyte donation treatment?'.
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