IVF Success Rates

When considering IVF treatment, learning about IVF success rates and understanding what these statistics mean is important to ensure you make the right decision about your future. 

Melbourne IVF, together with our sister clinics in New South Wales, Queensland and Tasmania are proud of the success rates we achieved. As a collective group we are responsible for more births through IVF treatment than any other fertility provider in Australia.

Understanding IVF success rates

What is an IVF treatment cycle

A typical in vitro fertilisation (IVF) cycle involves:

  1. A woman’s ovaries are stimulated through one to two weeks of fertility drug injections (ovarian hyperstimulation).
  2. Usually 36-38 hours after an injection to trigger ovulation, the oocytes (eggs) are collected from the woman in a procedure known as an oocyte pick up (egg collection), this is a day procedure performed under a light anaesthetic.
  3. On the morning of egg collection the male partner will usually produce a fresh semen sample.
  4. The eggs are then usually fertilised later that afternoon with the sperm in the laboratory and matured. Fertilisation of the egg can be through traditional IVF (sperm placed in petri dish with the egg) or IVF with intra-cytoplasmic sperm injection (ICSI) where one sperm is selected and injected into the egg.
  5. The embryos are cultured in the laboratory for five days before an embryo(s) is then transferred back into the woman’s uterus (fresh embryo transfer)
  6. Any remaining viable embryos are then frozen and may be transferred later (frozen embryo transfer).

An IVF treatment cycle is considered complete once all fresh and frozen embryos from the initial stimulated cycle have been used.

How are IVF success rates calculated?

There is no agreed format for reporting ‘success rates’ when it comes to IVF and therefore the data can be presented differently, resulting in varying outcomes.  

Complete IVF treatment cycle vs. embryo transfer

IVF success rates can sometimes be reported per complete IVF treatment cycle.  As explained above, a complete IVF treatment cycle can involve multiple transfers of embryos collected from the one egg collection. Success rates measured this way will therefore naturally be higher than success rates measured per embryo transfer.

Clinical pregnancy vs. live birth

Clinical pregnancy rates (defined as a pregnancy confirmed by a blood test and ultrasound scan, usually at around 6-8 weeks) per embryo transfer is most often what is reported. Not all clinical pregnancies however will lead to a live delivery. 

At Melbourne IVF, we most often measure IVF success rates as clinical pregnancy per transfer and as sadly not every pregnancy will result in a live birth, we quote live births per embryo transfer as well. This provides you with a more accurate understanding of your chances of success following each embryo transfer.

Important considerations

Each of the measures above measure the success rate once you reach the stage of an embryo transfer. Unfortunately, in some cases no embryos develop after the egg collection and therefore there is no embryo transfer. On some occasions, your fertility specialist may advise you to postpone the embryo transfer to carry out pre-implantation genetic screening on your embryos or to prevent ovarian hyperstimulation.

It is therefore important to understand what part of the IVF treatment cycle a particular statistic is measuring. There are also other factors that you need to consider and understand before you attempt to compare IVF success rates. These factors include:

Woman's Age

woman's age is the most important factor affecting the chance of pregnancy success. Female fertility starts to decline when a woman is in her 30's on wards and declines rapidly once the woman is over 40, with the average age of a woman undergoing a fresh IVF cycle being 35.9.  When looking at success rates ensure these have been broken into age bands. The IVF success rate of a 40 year old cannot be compared with that of a 30 year old.

Single embryo transfers

Australia has been a world leader in reducing the number of embryos transferred in an IVF cycle which reduces the chance of multiple pregnancies and therefore the risks to mothers and babies. Pregnancy rates should be interpreted in the context of when a single or double embryo transfer is undertaken. At Melbourne IVF we usually recommend a single embryo transfer.

Embryo development at time of transfer

Embryos that have grown to the blastocyst stage of development (day 5) have a greater potential to implant.  However, not all embryos will progress from cleavage stage (day 2) to blastocyst stage.  A poorer prognosis patient is likely to have lower egg numbers and will most likely have a cleavage stage transfer.  It is important that you are comparing ‘like’ with ‘like’.

The Melbourne IVF success rates represented in the following graphs are the fresh and frozen embryo transfer clinical pregnancy and live birth outcomes for FY2017-2018.  

Day five 'Blastocyst' embryo transfers comprised 78% of all fresh embryo transfers performed at Melbourne IVF in FY2017-2018. The outcomes listed below represent the results for blastocyst stage fresh embryos transferred on day five. 

FY 2017-2018, Fresh Blastocyst Transfer (Day 5)

Clinical Pregnancy
Live Birth

Age <30

45.5

37.9

Age 30-34

37.5

34

Age 35-39

37

27.4

Age 40-42

24.4

14.4

Age >42

13.6

3.9

FY2017-2018, Frozen Blastocyst transfer

Clinical Pregnancy
Live Birth

Age <30

34.4

29.5

Age 30-34

35.9

28.7

Age 35-39

29.9

23.4

Age 40-42

23.2

16.5

Age >42

21.5

13.8

In FY2017-2018, 95% of Frozen Embryo transfers were Blastocyst. The above graph shows the outcomes of these frozen blastocyst embryo transfers by women using their own eggs that resulted in a clinical pregnancy and live birth in FY 2017-2018. The results exclude preimplantation genetic testing (PGT).

FY2017-2018, Frozen Transfers with PGT

Clinical Pregnancy
Live Birth

Age <30

61.7

42.6

Age 30-34

44.6

37.7

Age 35-39

44.1

37.7

Age 40-42

36.4

30.3

Age >42

44

40

In the above chart,100% of PGT transfers are at the blastocyst stage. For our private patients, using their own eggs In FY2017-2018, 33% of our frozen blastocyst transfers utilised PGT. The following graph shows the outcome of the frozen blastocyst embryo transfers by women using their own eggs and pre-genetic screening that resulted in a clinical pregnancy and live birth in FY2017-2018.  

Want more information about IVF success rates?

At Melbourne IVF, we understand that interpreting IVF success rates can be complex. As well as interpreting the data available there are individual factors affecting your likelihood of success. We will always explain these factors as carefully and openly in relation to how any data is calculated. 

The most effective way to understand you, and your partner’s likelihood of success, is to arrange a consultation with one of our fertility specialists. Our role following a thorough assessment is to explain your treatment options and develop with you the most suitable treatment to give you the best possible chance of having a baby.

For further information on interpreting success rates you can refer to the FSA guide“Interpreting Pregnancy Rates: a consumer guide”.

If you would like to make an appointment please call us on 1800 111 483 or complete the form below.