Making sense of success rates
By Kate Brian, journalist, writer and author of four books on motherhood and fertility
When you’re considering where to have fertility treatment, the one thing you really want to know is which clinic is most likely to be able to help you to get pregnant. Looking at success rates is the obvious place to start, and most clinics will be keen to show you their results. When it comes to making comparisons, however, things aren’t always quite as straightforward as they seem and it can be difficult to draw conclusions about your own chances of success from these figures.
How are rates published?
One of the most important things to bear in mind is that different clinics publish these rates in different ways. You can only begin to make sense of them if you are sure that you are comparing like with like. Some clinics publish live birth rates while others give pregnancy rates, which will always be higher as unfortunately not every positive test will result in a live birth.
Success rates also vary depending on age, your fertility problem and whether you are using your own eggs or donor eggs. If you are looking at one overall average success rate for a clinic which includes all types of treatment and all patients, this may have little relation to your own individual circumstances.
Thinking about age
Age is one of the key factors when it comes to assessing your chances of success with fertility treatment, as the biological clock means that female fertility declines rapidly once a woman reaches her mid thirties. Correspondingly, IVF success rates fall quite sharply depending on the age of the woman – and if a clinic is treating a lot of older women using standard IVF treatment this will have an impact on success rates.
What you really want to know is the success rates for someone of your age, and most clinics now break down success rates by women’s age which is more useful as it does give a general picture for your age group.
Of course, it’s eggs which really make the difference when it comes to reproductive ageing, and so women who use donor eggs during their treatment don’t face the same age-related decline in fertility. This means that success rates for treatment with donor eggs remain more stable regardless of age.
How much can I tell from success rates?
Success rates can give you a broad idea of how well a clinic is doing, and can prove to be a useful starting point as long as you understand their limitations.
Success rates are partly dictated by the patients treated at the clinic, by their age and the duration and nature of their problems. If lots of patients are arriving at a clinic after repeated unsuccessful attempts elsewhere, if they have more complex fertility problems or if they are older and are using their own eggs, this will have an impact on the clinic’s success rates.
Of course, what you really want to know is how likely it is that you will get pregnant at the clinic, but an overall success rate may bear little relation to your individual chances of having a baby. If you want a more detailed view of what your own likelihood of success may be, you are usually better off discussing this with the medical team who are caring for you. They will be able to factor in all the individual issues which can make a difference to the outcome and to give a more realistic idea of your chance of success tailored to your circumstances.
Writer and journalist
Kate Brian is a journalist, writer and author of four books on motherhood and fertility, including The Complete Guide to IVF. Kate started writing about the patient perspective on infertility after having IVF herself.
Currently, she contributes to various types of media as an expert on fertility and writes her own blog, where she gives all the latest news and views on fertility issues, as well as useful advice and links for anyone trying to have a baby.