Success Rates Explained


19 July 2018

IVF success rates are designed to help you understand the likelihood that you will take home a baby. IVF success rates can look different and while this can be confusing, there’s a simple way to explain why there are differences, and this is because, put plainly, success rates are different.

What are IVF success rates?

IVF success rates are designed to help you understand the likelihood that you will take home a baby. IVF success rates can look different and while this can be confusing, there’s a simple way to explain why there are differences, and this is because, put plainly, success rates are different.

How are IVF success rates represented?

If you visit any particular clinic’s website, chances are you’ll come across a specific page detailing their individual success rates. Normally, they are represented in a type of bar chart and include different statistics according to patient age and, sometimes, treatment or cycle type. The graph should specify the time period from which the data was drawn.

All IVF/fertility clinics in Australia must adhere to strict guidelines put in place to ensure you are provided with accurate and easy to understand data. The guidelines are set and monitored by the Australian Health Practitioner Regulation Agency (AHPRA) and the Reproductive Technology Accreditation Committee (RTAC). The underpinning values of the guidelines are to ensure success rates are advertised in a way that allows the public to make an informed choice about their healthcare and fertility treatment.

It is important for each clinic to clearly show what data is being presented in their success rates, including the age of the women and the type of treatment that was completed. You can access success rates via most clinic websites but you can also view success rates according to the national or state average through industry initiatives/bodies such as the Australia New Zealand Assisted Reproductive Database (ANZARD).

What factors influence the success of bringing newlife into the world via IVF? There is a lot of contrasting information out there about IVF treatment success rates. Simply put, success rates depend on a number of factors including the quality of the clinic, patient’s age, the types of treatments included and whether the number is based on clinical pregnancies or live births.

A clinical pregnancy is a pregnancy in which at least one of the following criteria is met:

  • known to be ongoing at 20 weeks
  • evidence by ultrasound of an intrauterine sac (with or without a fetal heart)
  • examination of miscarriage products reveal placental tissue, or
  • an ectopic pregnancy has been diagnosed by laparoscope or by ultrasound.

A live birth is when a live baby is born.

Each IVF clinic represents unique success rates. Differences in clinics are mostly due to the type of patient they treat, but also quality of the lab environment and skill and experience of the staff including the embryologists and fertility specialists. It’s also important to note the underlying cause of infertility and the clinic’s treatment regime. It’s always a good idea to ask whether the unit has a policy to transfer the best embryo in a fresh embryo or frozen embryo cycle and if they recommend genetic testing (PGS) for all patients.

The types of cases taken on by the clinic can affect the overall success rates of that particular clinic. Some journeys to pregnancy are more difficult than others, and not all clinics take on complex cases. Unfortunately, the reality is that a lot of clinics only take on patients with a high probability of achieving pregnancy due to a lack of resources or an aim to keep success rates high. Other clinics with high quality science are most likely to treat all patients, including those who may have been unsuccessful elsewhere or need extra help with donor gametes or genetic testing.

If you look at a clinic’s success rates, most of the time they reflect a number of different age groups. As with natural conception, the likelihood of achieving a pregnancy through IVF (or any type of fertility treatment) decreases with increasing maternal age.

Currently, the likelihood of success in patients under 30 is around 4 times higher than in patients over 40, but latest research has suggested that all age groups experience an increase in the likelihood of pregnancy in subsequent cycles.1

Clinical pregnancy vs. live birth
Most IVF clinics show two sides to their success rates – one column depicting clinical pregnancies and one representing live births. No matter which clinic you are looking at, the number of live births will always be lower due to the risk of miscarriage.

Type of treatment
Not all success rate graphs depict the same type of treatment, and this can contribute to the differences in success rates between clinics. For example, some clinics depict success rates from blastocyst transfers, which means the embryo is transferred back into the uterus around day 5. Prior to research showing that blastocyst transfers were the most effective type of transfer, most clinics used a technique called cleavage stage transfer, which occurs on day 2 or day 3. Currently, some clinics show success rates according to one of these two techniques while others still represent both.

No matter which type of treatment or transfer the success rates are referring to, it should always be stated on the graph or success rates page.

Understanding your chance of success

When looking at a clinic’s success rates, it’s important to note that their overall success rate may or may not apply to you and your treatment needs. It’s also important to remember that pregnancy and birth rates for patients having routine IVF treatment over the age of 35 can decrease quite significantly.

Your Fertility Specialist will advise you as to your specific treatment options, and will also explain to you your chances of success, taking into consideration your type of infertility, your age and your treatment. Assisted Reproductive Treatment (ART) procedures have progressed rapidly since their development and so have the associated success rates, but generalised success rates can be misleading due to the individuality of each patient’s situation. There are many hurdles to cross during treatment and it is important to keep in mind that they all need to be successfully crossed in order to achieve a successful pregnancy.

Talk to your Fertility Specialist, nurse and counsellor about these hurdles and your specific treatment, and ask as many questions as you need to. It is better to be well prepared than to have to deal with unexpected events during this important, and sometimes-difficult stage of your life.

Success rates can be affected by many factors, including:

  • Genetic factors
  • Fertility history
  • Age of the female partner
  • Lifestyle factors including weight and smoking
  • Conditions contributing to infertility
  • Quality of eggs and number of eggs recovered
  • Quality of sperm (including motility and ability to penetrate the egg)
  • Processes in the laboratories; and
  • Skill and competence of the treatment team

Although ART offers valuable options for the treatment of fertility problems, the decision to use ART involves many factors in addition to success rates. Going through repeated ART cycles requires substantial commitments of time, effort, money, and emotional energy. Therefore, you should carefully examine all related financial, psychological and medical issues, before beginning treatment. You may also wish to consider the location of the clinic, the counselling and support services available and the rapport that staff have with their patients.

You can read more about success rates and choosing an IVF clinic from this handy guide written by Access.

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