When we ask the featured fertility clinics on our website about success rates we do so as we believe it is something that patients want to know. Due to the fact that we ask them to volunteer the information, it will never be as comprehensive or as detailed as, for example, the HFEA who provide data on fertility clinics in the UK. However, we still think that it makes a valid contribution to the profile of the clinic (we hope that you agree).
Why you shouldn’t compare success rates….
That being said, success rates shouldn’t be used on their own to make a decision on whether to choose one IVF clinic over another. There are lots of reasons why a clinics success rate may be lower than another clinic. For example, an IVF clinic may be expert at treating older women (over 40 years) for IVF (using own eggs) and so may attract patients in this age group. However, the success rates for older women who use their own eggs will always be a lot lower than that of younger women (due to eggs ageing as we age). So comparing this type of clinic with a clinic which only takes younger women wouldn’t be fair.
There are IVF regulatory bodies in European countries which collect IVF success rate data. Not all of the data is visible to the public unfortunately (although some is e.g. in Spain). Furthermore, in some countries there is no legal requirement for a clinic to submit their data at all. Our guide on IVF abroad provides more information about this for each country.
Within our website, we ask our featured fertility clinics to tell us their success rates, multiple birth rate and the number of embryos transferred. The reason we ask for all three values is to understand whether there is any indication that the success rate could be down to the number of embryos being transferred. If multiple embryos are transferred there is an increased chance of pregnancy. However, this will also increase the chance of a multiple pregnancy – which isn’t a good outcome for a number of reasons.
What do the success rates actually mean?
Here’s a quick guide to some of the terminology used when talking about success rates on our website.
Clinical pregnancy – this means that a foetal heartbeat has been detected at usually 6-7 weeks within the gestational sac (a fluid filled sac containing the embryo). The success rate is described as the number of clinical pregnancies per 100 cycles (initiated, aspirated or embryo transfer cycles). Drilling down to uncover this specific information is difficult unless it is mandatory reporting. In our website we assume it is per embryo transfer. As this is an assumption, it is yet another reason not to compare outright one clinics pregnancy rate with another.
Chemical pregnancy – this means that the hormone indicators of an early pregnancy have been detected. Human Chorionic Gonadotropin-HCG – is secreted by the placental cells of the embryo. As their number increases, so does the level of HCG. Measuring this hormone level is an indicator of the health of the pregnancy as the level should double every 48 hours in early pregnancy. The chemical success rate is the number of pregnancies per 100 cycles (either initiated, aspirated or embryo transfer cycles). This rate is not used on our website but it is useful to understand.
Live birth rate – the number of live babies that are delivered per 100 cycles (as described above). This rate is usually much lower than the clinical pregnancy rate as unfortunately some pregnancies result in miscarriage.
Cumulative pregnancy rate. Some clinics on our website describe a cumulative pregnancy rate. This is a fresh cycle followed by one or more frozen cycles with the surplus embryos if available. It will be higher than a pregnancy rate achieved just with a fresh cycle. It is worth understanding the difference and it might be something to ask the clinics about when you contact them.
It is all a bit confusing; your IVF team abroad should be able to explain fully how they report their success rates. It certainly would be a good idea to find out exactly how they calculate this rate so that you have a good understanding of the potential success of your treatment.
Take a look at the profiles of our feaured fertility clinics in Europe.