When you're trying to get your head around the NPSU's IVF statistics, it's important to remember that the data reflect the average of what happens to all couples undergoing IVF treatment. The data include the young and the old, couples on their first treatment cycle and those on their tenth cycle, couples who have lots of eggs and those who have only a few and so on. The report thus provides a global view of the workings of IVF.
Note: All statistics in the following sections relate to the year 2006 in Australia and New Zealand.
In 2006 the average live birth rate after a stimulated cycle for all clinics in Australia and New Zealand was 19.6 per cent. Live birth rates vary between clinics, so you may want to look closely at these figures before choosing your clinic (I talk more about choosing a clinic in Chapter 3).
I The top 25 per cent of clinics had a live birth rate of 23 per cent or more.
I The middle 50 per cent of clinics had a live birth rate between 15.6 per cent and 22.9 per cent.
I The bottom 25 per cent of clinics had a live birth rate of 15.5 per cent or lower.
Almost 30,000 stimulated cycles were started, but 10 per cent were cancelled before egg collection. The most common reasons why cycles are discontinued at this stage are
^ Too few large follicles are visible on ultrasound
^ Hormone levels indicate that the best time for egg collection has passed
^ Too many follicles are seen on ultrasound or hormone levels indicate an excessive response to stimulation (I explain the risk of ovarian hyperstimulation syndrome in Chapter 10.)
^ Ultrasound picks up a cyst or some other problem that needs to be fixed before egg collection
Of the women who underwent egg collection, about 1.5 per cent had the misfortune of not getting any eggs.
Of all the women who had eggs collected, 88.5 per cent had an embryo transfer. The common reasons why some couples don't get to embryo transfer include
^ None of the eggs fertilise
^ The eggs don't fertilise normally and so can't be transferred
^ The fertilised eggs arrest, meaning that they fertilise normally and may even start to divide but then stop developing
^ The woman's high risk of ovarian hyperstimulation syndrome means the safest option is to freeze the embryos and wait for her hormone levels to settle down before transferring one or two of the frozen embryos (I explain why this is a safer option in Chapter 10.)
The NPSU report uses the term clinical pregnancy to define pregnancy and it includes
Ectopic pregnancies (when the embryo implants and starts to grow in the fallopian tube or somewhere else outside the uterus)
Pregnancies where a sac with a foetus can be seen on ultrasound inside the uterus; the foetus may or may not have a heartbeat
Pregnancies that are still going at 20 weeks gestation
Of the couples who started stimulated cycles, 25.2 per cent had a clinical pregnancy; and of the couples who reached embryo transfer, 32.1 per cent had a clinical pregnancy.
Having a baby
Aha, the most important statistic:
1 19.6 per cent of couples who started a stimulated cycle had a live birth 1 25 per cent of couples who had an embryo transfer had a live birth
So, one in five couples who started a stimulated cycle had a baby and these odds improved to one in four for those couples who reached the embryo transfer stage.
Of the approximately 17,500 cycles that were started with the intention of transferring frozen embryos, almost 91 per cent resulted in an embryo transfer and the remainder were discontinued because none of the embryos survived. Of the couples who had a transfer, 20.7 per cent had a clinical pregnancy and 15.5 per cent had a live birth.
Understanding Your Chances of IVF Success
So, what are your odds of having a baby with IVF? The answer is: It depends.
Several factors are at work here:
1 Factors relating to your treatment, such as what type of treatment you have, how you respond to hormone stimulation, how many eggs are recovered, the number and quality of the embryos, and whether you have frozen embryos
In this section I show how some of these factors play out in the big IVF
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