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IVF Success Rates Explained

IVF Success Rate Explained

Judging fertility clinics abroad on the basis of their success rates is one of the most widely used methods patients use to help them choose their ideal IVF clinic but unfortunately, it is not always the wisest one. You might ask why this is so but in fact success rates are not solely achieved by the actions of the clinic but rather they are the result of a number of interrelated factors. The clinic plays a large part as a result of the professionalism and experience of its staff and the technologies employed in treatments but so too do patients.

In the majority of cases it is a patient’s individual situation, their condition and medical history which influences the result of the treatment rather than the clinic itself. A patient’s age, genetic factors or various reasons for infertility play a crucial role in determining IVF success.

It is highly advisable to do your own research prior to choosing the best IVF clinic. Always analyse all the medical and psychological aspects that the IVF treatment process entails and only choose to proceed if you ready to commit financially to what can be a substantial investment.

How IVF success rates are calculated and presented by clinics

There is not a standard and accepted way for treatment providers to share information regarding success rates. Comparing success rates between clinics in the same country can be challenging sometimes but when you attempt to compare rates between different countries the task becomes even harder. Defining, calculating and reporting success rates varies between clinics and as a patient you should be aware that the criteria used to define these rates will impact greatly on the final figures quoted.

To help you distinguish between the various criteria clinics employ to report success rates we have illustrated some of the benchmarks used to present and calculate rates.

IVF success rates presentation

IVF success rates per start of the cycle

This method of reporting success rates is based on the chances of success with repeated cycles rather than on one cycle. This criterion is useful for patients who are assessing their overall chance of achieving pregnancy and is a very accurate tool if it is combined with age or a patient’s medical condition.

IVF success rates per embryo transfer

This reporting method is usually calculated on the basis of the number of patients reaching the stage of having embryos that are ready to be transferred. This rate does not refer to clinical pregnancy rates or live birth rates that can vary from this baseline figure.

Cumulative success rates

This method is used to reflect the overall effectiveness of a particular treatment over a specific number of cycles.

IVF success rates calculation

A biochemical pregnancy

A biochemical pregnancy refers to a miscarriage within the first four or five weeks of the embryo implanting.

Pregnancy at week 12

This is usually when the first ultrasound would take place and is the moment when the foetus is fully formed.

Live Birth

This calculation is triggered when a baby is born and displays signs of life whatever gestational age it has reached.

It is easy to see therefore why so many find trying to analyse and compare success rates so difficult when they are presented in different ways and calculated on the basis of different outcomes. The IVF success rates you will see on clinic websites will invariably be generic, that is to say, they will be measured against patients with different treatment requirements which could be as diverse as male factor infertility or ovulatory disfunction. It may also be difficult to compare a generic clinic with one that helps patients with a specific condition like low ovarian reserve – the latter may be more successful at treating such patients than generic clinics but due to the nature of the condition it follows that their overall success rate may appear low in comparison with other providers.

IVF success rates by country – A comparison

There are differences in IVF outcomes between popular countries. It is not recommended however to assess the treatment quality between countries solely based on IVF success rates. Differences in IVF success rates between countries may not reflect differences in the quality of IVF treatment between countries – and the same rule applies when comparing the IVF clinics.

IVF with own eggs – success rates​ by age in Europe

The effectiveness of IVF treatment with own eggs will vary significantly depending on the age of a female patient. Additionally, there are many other parameters that influence the effectiveness of treatment. These include, amongst others:

  • Age of a woman 
  • BMI, 
  • Quality and the number of oocytes collected 
  • Quality of the male partner’s sperm. 

That is why it is so important to always ask about your own individual chances and not about average success rates in the IVF clinic. When publishing data on treatment effectiveness, the best clinics will take different patients’ age groups into account. However, this still might not be sufficient to be able to effectively compare success rates between IVF clinics.

The following table draws upon data collected from European registries by ESHRE (European Society of Human Reproduction and Embryology) and provides a really useful comparison of live birth rates by patient age and shown as percentages. The first thing you will notice about the data is that there is a substantial decrease in success rates for women over 40 with the exception of one country. The optimum age for IVF with own eggs is under 34 and success rates can fluctuate anywhere between 25% and 30% and there is also a smaller decrease in success rates for those women aged between 35 and 39 compared to their younger peers. The exception to most of these figures is Latvia but with only five clinics and a smaller number of cycles being carried out in the country compared to somewhere like Spain you would expect to see rather different results.

This comparison table is a useful starting point but as we shall see throughout this article, success rates are subject to complex variables and are collated and presented in different ways.

Edit
IVF with own eggs in popular countries in Europe* <34 35-39 ≥40
Spain 25.8 23.2 11.7
Portugal 26.6 21.2 14.3
Czech Republic 29.7 21.6 8.9
North Cyprus** no data no data no data
Greece 30.4 22.8 9.7
Ukraine 25.4 22.7 14.1
Poland 30.5 25.9 12.9
Russia 30.3 24.1 12
Latvia 29.4 33.6 20.7
Denmark

30.4 20.2 12.3

Source: ART in Europe, 2017: results generated from European registries by ESHRE*
Supplementary Table SX Aspirations, pregnancy and delivery rates by age distribution (years) of women treated with ICSI in 2017.
Pregnancies per embryo transfer.
**North Cyprus is the self–proclaimed state recognised only by Turkey and is not providing and data to ESHRE EIM Consortium.

IVF with donor eggs – success rate​ – in Europe

In the case of donor egg success rate, the effectiveness is independent of the patient’s age. However, remember that your own treatment history and its medical parameters may be important for the expected effect. That is why you should always ask the clinic about your own personal chances of success and not about the average effectiveness of treatment.

The following table produced by ESHRE (European Society of Human Reproduction and Embryology) uses data collected by different European registries to show success rates in countries which offer fresh and frozen egg donation treatments. No information is recorded about the age of patients as this does not have any direct impact on outcomes.

Interestingly the countries that perform the largest number of cycles in Europe including Spain suggest that fresh cycles appear to attract a higher success rate. Success rates for frozen cycles vary between 34.4% in Poland to a high of 61.6% in Ukraine. According to the data which was recorded in 2017 Ukraine was achieving the highest frozen cycle success rates at 62.2% and this compared to the lowest success rate of 23.1% which was recorded in the Czech Republic.

Once again, although this table is useful do remember that success rates may be collated and presented differently by clinics and countries.

Edit
Egg donation success rates in popular countries in Europe* Pregnancies per fresh ET (%) Pregnancies per thawed ET (%)

Spain 54.7 51.1
Portugal 52.6 40.6
Czech Republic 42.2 23.1
North Cyprus** no data no data
Greece 54.7 50.1
Ukraine 61.6 62.2
Poland 34.4 44.7
Russia 48.0 45.0
Latvia 39.5 42.3
Denmark

38.6 33.7

Source: ART in Europe, 2017: results generated from European registries by ESHRE*
Supplementary Table SVIII Pregnancies and deliveries after ED (fresh and frozen cycles) in 2017. In Egg Donation cycles, the age of the recipient women had no influence on outcomes. Pregnancies per embryo transfer (fresh and frozen)
**North Cyprus is the self–proclaimed state recognised only by Turkey and is not providing and data to ESHRE EIM Consortium.

IVF success rates in USA

TThe IVF success rates in USA are monitored by SART (Society for Assisted Reproductive Technology) and published by CDC (Centers for Disease Control and Prevention). Due to the large number of cycles and accurate data collected from IVF clinics, SART may be a very good reference point for any patient undergoing IVF treatment.

IVF own eggs – success rates by age in the USA

The general success rates – live births – for IVF with own eggs (including patients with all types of infertility diagnosis) in the USA are:

  • 49.7% for women younger than 35
  • 44.8 for women aged between 35 and 37
  • 39.6 for women aged between 38 and 40
  • and 22.6 for women older than 40

The IVF statistics above are presented as the percentage of embryo transfers resulting in live-birth deliveries and the results are based on 107,795 IVF cycles (2019)*.

IVF with donor own eggs (egg donation) – success rates in USA

The general success rates – live births – for IVF with donor eggs – egg donation (including patients with all types of infertility diagnosis) in the USA are:

  • Fresh oocytes from the donor (fresh embryo transfer): 53.9%
  • Frozen oocytes from the donor (fresh embryo transfer): 45.8%

The IVF statistics above are presented as the percentage of embryo transfers resulting in live-birth deliveries and the results are based on 24,042 egg donation cycles (2019)*.

*Source: Assisted Reproductive Technology (ART) by National Center for Chronic Disease Prevention and Health Promotion, Division of Reproductive Health

IVF success rate UK

We have provided data in the following tables which illustrate some interesting differences between published success rates in the UK and Europe. Although there is no definitive data which points to the number of patients who travel abroad for fertility treatment from the UK we are aware that this number is significant. Feedback from patients themselves and clinics throughout Europe suggest that UK patients continue to travel for various reasons and this number does not appear to be reducing at all.

Patients from the UK obviously travel for different reasons. It may be down to success rates advertised by non-UK clinics or a combination of other variables including costs, access to treatments for older women, reduced waiting lists, access to treatments not readily available or legal in the UK, or because of the better availability of donors.

You will notice that overall success rates quoted in the UK tend to be bit lower than their European equivalents. However, it does better on average than European countries in terms of treating younger patients seeking IVF treatments using their own eggs. For instance, the UK boasts an average success rate of 32% for women under 35 using their own eggs – this figure is higher than in the European countries (showed as a pregnancy per embryo transfer) we feature in this article although it remains significantly lower than the figure quoted in the U.S. However, the success rates for women over 40 appear to be lower than in European countries – this may be one of the reasons why a large number of women over 40 travel from the UK for treatment and consequently the overall number of women who collectively receive IVF cycles in Europe is higher than the absolute number in the UK.

The differences in success rates between the UK are Europe are more significant when we consider success rates for treatments involving egg donors. In general, terms if we take overall success rates European treatment providers offer success rates which are 10% above the UK average – even if we consider differences in data presentation – in the table above the egg donation success rates are presented as pregnancy per embryo transfer while in the UK they are presented as live births. We know from different countries that the reasons for patients travelling from the UK include the desire for anonymous donors and cost as well as success rates. The majority of those travelling from the UK are seeking IVF treatments with donor eggs and the number of such procedures in Europe dwarfs the number undertaken in the UK. The availability of donors and no waiting lists are also drivers for more patients travelling from the UK.

IVF success rates in the UK are published by the HFEA (Human Fertilisation and Embryology Authority) – the UK fertility regulator.

The IVF success rates for IVF with own eggs by age in the UK are:

  • 32% for women under 35
  • 25% for women aged between 35 and 37
  • 19% for women aged between 38 and 39
  • 11% for women aged between 40 and 42
  • 5% for women aged between 43 and 44
  • 4% for women aged between 45 and 50

IVF statistics above are presented by HFEA as birth rates per embryo transferred and the results are based on 40,358 IVF cycles (2019)*.

The IVF success rates for IVF with donor eggs (egg donation) by age in the UK are:

  • 34% for women under 35
  • 37% for women aged between 35 and 37
  • 31% for women aged between 38 and 39
  • 33% for women aged between 40 and 42
  • 35% for women aged between 43 and 44
  • 31% for women aged between 45 and 50

IVF statistics above are presented by HFEA as birth rates per embryo transferred and the results are based on 5,368 egg donation cycles (2019)*.

Source: Fertility treatment 2019: trends and figures by HFEA

IVF success rates and choosing an IVF clinic

We can not emphasise enough the need to closely examine all the variables that have contributed to the publishing of success rates. Private IVF treatment is a significant investment and any clinic to choose to manage your care and treatment should be done so with due diligence.

You should not automatically accept any figures that are quoted without first asking how these have been calculated and whether they are specifically relevant to you, taking into account your age, medical history and any diagnosis you have received. The following quotes show the complex nature of compiling statistics and how difficult it can be for clinics on generic information.

Equally, it is important to realise that success rates are one way of deciding upon a treatment provider – you should take into account other factors such as whether you feel confident that your care and support needs will be satisfactorily addressed by the clinic and whether you feel comfortable in investing in the treatment offered.

Although it is true that the quality of IVF treatment can affect the outcomes, patient characteristics – such as patient’s age, race or ethnicity, infertility diagnosis, or existing medical conditions – can also contribute to differences in IVF success rates.

Commonly Asked Questions About the US National ART Surveillance System (CDC USA)

If you’re comparing two or more clinics, you may want to consider the multiple other variables (cost, location, patient ratings) to find a clinic that meets all your needs and expectations rather than deciding on success rates alone.

HFEA: UK fertility regulator

Misleading IVF success rates​

Even if data regarding clinic success rates comes from a public report you still need to apply a degree of caution. Firstly, remember that clinics can be ‘creative’ when measuring and reporting their success rates. They quite understandably want to show the highest numbers possible to encourage more patients and these figures will often appear to be significantly higher than the reported national average.

There is nothing wrong per se with the fact that an IVF clinic will want to calculate success rates based on their particular algorithm but be aware that those clinics with higher success rates will ordinarily want to charge higher prices. It is therefore important for you to ensure these success rates are appropriate in your specific case.

It is worth also applying caution to IVF refund programmes which are now gaining popularity, which may “promise” a 100% success rate or a live birth. Such IVF packages are financial programmes that involve risk-sharing between the clinic and patients. From a purely medical perspective, they can’t guarantee anything (for instance, success rates, pregnancy, live birth) but merely offer a money-back guarantee – “a refund” based on the expected outcome. That’s why they are often called the IVF money back guarantee programmes.

IVF success rate calculator

How to check the prospects of a successful outcome based on your individual history?

Increasingly we are seeing technology employed to predict the likely outcomes of IVF treatment and the more sophisticated AI becomes the more likely we are to see more accurate predictor models.

One of the most accurate models that has been developed to predict the potential success of particular treatments was developed by the Society for Assisted Reproductive Technology (SART) in the United States. The SART Patient Predictor is a very sophisticated tool that has been evolving since 2006. Based on continual analysis of over half a million cycles and over three hundred thousand women the calculator is designed to predict the chances of successful outcomes based on an assessment of each patient’s personal situation.

Patients are requested to answer questions relating to their physical self such as height and weight as well as medical questions about any diagnosis they may have received. Each calculation is highly personalised and is based on the assumption that the individual has not received any IVF treatment prior to recording their details.

The patient predictor will then attempt to accurately predict your chances of a live birth as well as proving advice and information on the risks that might be associated with any IVF treatment. For instance, SART might predict the chances of multiple births as a result of multiple embryo transfers and quantify the danger from such procedures.

It is worth noting that the SART predictor is only one of the tools available to assess potential IVF outcomes and only features data captured from U.S. patients. As technology develops we are likely to see more tools which attempt to forecast outcomes and inevitably these will become more accurate in time.

One last caveat from us if you are thinking of, or currently using a predictor tool, it is always worth comparing the predicted success rates with the clinic of your choice. If there is a significant difference between a predicted figure and the success rate quoted by the clinic you will need additional time to evaluate the figures.

You may be interested in reading more about: IVF success rates calculators

IVF success rate – other resources​

If you are looking for more information regarding chances of success when going through an IVF cycle we highly recommend checking out the resources below:

IVF success rates – FAQs

How are IVF success rates calculated?

There is no definitive or standardised way of calculating IVF success rates. Treatment providers are well aware that patients treat success rates vert seriously and largely base their choice of clinic on these. Consequently, it is in the interests of the clinic to promote favourable rates. They might calculate success in absolute numbers i.e., 1,000 patients per year are treated in the clinic and 500 live births are achieved or they may calculate success on another variable such as the number of patients who achieve a clinical pregnancy (confirmed by high levels of pregnancy hormone HCG, ultrasound showing a gestational sac or heartbeat).

What determines IVF success rate?

IVF success rates are created by treatment providers using a range of methods to record data. In some countries treatment providers are highly regulated and independent audits undertaken by national bodies or registries attempt to standardise the reporting of success rates. In other countries where regulation is not so tightly organised clinics are able to present success rates flexibly which means they will invariably highlight those treatment areas which are particularly successful or particularly in demand from patients.

What is the success rate of IVF on the first try?

This totally depends on a number of factors including whether the IVF cycle uses a woman’s own eggs or a donors; the age of the patient, their medical history and their particular diagnosis. Based on the figures we have been given in this article however that the success rate of IVF on the first try for a woman aged under 35 using her own eggs is around 30%. This figure drops to about 10% to 15% for women over 40.

Is IVF 100 percent successful?

No, even after forty plus years of successful IVF treatments nothing can be guaranteed. Success rates for women using their own eggs have risen over the last decade but this rise has been relatively slow. Success rates rise when treatments involve donor eggs or sperm but even then they might only rise to 50% to 60%.

Which IVF clinic has the highest success rate in Europe?

As success rates can be presented in different ways by clinics it is very hard to identify one clinic as the leader in terms of IVF success rates. There are European countries who have developed very successful track records and these tend to be the most popular destinations such as Spain, Greece or the Czech Republic. There are many other countries however who are ‘rising stars’ in the IVF field such as those countries in the Eastern part of Europe. As we have said throughout this article success rates need to be approached with a deal of caution, a clinic that boasts high success rates may not be the right one for you, bearing in mind your age and your specific treatment needs. Choosing the right IVF clinic is a personal choice; success rates are important but you do need to bear in mind many other variables which are specific to you.

Aleksander Wiecki
Aleksander Wiecki
Aleksander is an advocate of transparency and truth about IVF treatment and patients’ experience manager. With strong expertise and background in the IVF and infertility industry including IVF clinics and genetic laboratories Aleksander strongly believes that there is a gap between IVF patients and clinics. This is a gap where patients may fall for the most common IVF treatment traps during their infertility journey. That’s why patients need help and support which they don’t necessarily get from IVF clinics. The support which comes from an objective, trustworthy and reliable source. Aleksander is a regular guest at ESHRE annual meetings, the Fertility Show in London, the Fertility Forum, the IMTJ - Medical Travel Summit, Fertility Exhibitions and conferences around the world.

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