Understanding success rates

Different clinics report success in different ways. We use the chance of a baby from a single treatment cycle.  This is also the preferred way to report results for the New Zealand consumer group, fertilityNZ and SART (the Society for Assisted Reproductive Technology) in the United States

For IVF, this includes using both fresh and frozen embryos from a single egg collection.  Over half our births from IVF in younger women come from using frozen embryos. 

When selecting a clinic, it’s important to check what measure they use when reporting their success rates. Many use ‘clinical pregnancy per embryo transfer’, which excludes:

  • People who do not have any eggs
  • People whose eggs don’t fertilise
  • Pregnancy loss or miscarriage

Clinical pregnancy rate per transfer can also be increased by transferring more than one embryo at a time, which carries the risks and complications of twins and even triplets to the mother and children.

Our booklet Pathway to a Child has comprehensive information on the chance of success with IVF and other treatments. 

Here are our most recent results for a single IVF egg collection cycle.  It covers all women having an egg collection, including those who did not get any eggs, those whose eggs didn’t fertilise and those whose pregnancy sadly miscarried.

The figure above is based on all egg collections at Fertility Associates clinics over the last three years for which we have birth results

Overall, IVF gives about twice the chance of pregnancy per treatment than nature gives for fertile people of the same age per month. This is because IVF compresses several months’ worth of eggs into one treatment cycle.


Your personalised chance of success

It is your personal chance of success per treatment that is important. The major factors contributing to individual success are:

  • The woman’s age at egg collection
  • The number of eggs collected

If you are using an egg donor, it is the donor’s age that matters. When using frozen embryos, it is your age when the embryos were created.


The numbers you are likely to have in an IVF cycle can be estimated from the level of a hormone called AMH (Anti Mullerian Hormone). Our doctors customise the dose of medications and the type of ovarian stimulation based on your age, AMH level, and other information from your medical history. Having 5-10 eggs gives about twice the chance compared to having 1-2 eggs. However, having more than 10 eggs only adds a small extra benefit.

The chance is very similar whether it is your 1st, 2nd or 3rd cycle, unless some major problem or issue shows up in the first cycle.

How do we compare?

Fertility Associates has excellent success rates that are well above the American average, embryo for embryo.


We compare our success rates with clinics in the USA, as they have some of the highest pregnancy rates internationally and their clinic results are published with enough detail to allow accurate comparison. 

The graph below shows the chance of a single embryo giving rise to a baby at Fertility Associates compared to the USA average*, following fresh embryo transfer.

We used to compare our success rates with clinics in Australia, however this information is no longer available.

*We can’t compare pregnancy rates with the USA directly, because American clinics usually transfer two embryos at a time, unlike in New Zealand where we transfer one embryo at a time for the mother and child’s safety. 

Fertility Cover

Many clinics make promises, but we put ourselves on the line with our Fertility Cover programme.

We are the only clinic in Australia and New Zealand that does this.

Just like nature, fertility treatment may take some time to achieve success. The chance of having a child after 1, 2, 3 or more cycles is called a cumulative pregnancy rate.

Our Fertility Cover programme gives you 3 chances to have a baby, with a 70% refund if you are unsuccessful. The programme has been going for 5 years, with 85% of people starting Fertility Cover having a baby.

About 85% of patients aged 39 or younger are eligible for our Fertility Cover programme.



Meet the team