ANDREW COUTTS, MA (Ed), BA (Law),BSc (Econ) Hons
Andrew Coutts is a regular speaker, writer and commentator on fertility issues and has been involved in developing numerous patient engagement events throughout Europe.
Dr Dimitrios Dovas, Medical Director the Newlife Center of Reproductive Medicine, in Thessaloniki, Greece agrees that IVF clinics use different strategies to highlight the efficacy of their work, but any statistical claim employed cannot be effective unless it can be backed by empirical proof:
“I feel that it is our responsibility as fertility specialists to explain thoroughly to our patients the chances of them having a successful outcome following a certain treatment approach. We are in the era of individualized treatments and this includes individualized assessments of the chances of success. Here at Newlife our team will assess your case thoroughly and will provide you with reasonable recommendations for your fertility problem, backed by the latest scientific data”.
There are various statistical ways to report the treatment outcome following fertility treatments. Some of the most commonly used are:
Pregnancy rate (%):It shows how many women become pregnant (have a positive pregnancy test) following IVF treatment, per 100 treatments.
Clinical pregnancy rate (%): How many women show evidence of pregnancy by ultrasound parameters (gestational sac, fetal heartbeat) following fertility treatment, per 100 treatments.
Live birth rate (%):Number of live-birth deliveries expressed per 100 treatment cycles. Live birth is defined as the delivery of a fetus with signs of life beyond 20 weeks of gestation. Multiple births (twins etc.) are considered single birth events.
Dr Dovas points out that clinics can only work with the information they have to hand and consequently there are bound to be variances in the way that success rates can be reported:
“It is obvious that the best way to report the results is by using the live birth rate. In some cases, it is difficult to do so, as in many cases people are lost to follow up because they fail to report the pregnancy outcome to the IVF clinic. Therefore, many of the IVF centres report pregnancy rates or clinical pregnancy rates”.
As we all know the devil is always in the detail and clinic success rates are no different as Dr Dovas explains:
“It is important to specify when reporting success rates what the main denominators are. For example, there are huge differences when rates are expressed per treatment cycle started, as opposed to per aspiration or per embryo transfer.
Clinics that treat older women have high cancellation rates, as many of these women fail to reach an embryo transfer due to poor egg quality. If these clinics report results per initiated treatment cycle, all results will not be comparable to a clinic which treats young women and has extremely low cancellation rates.
Additionally, many clinics report cumulative pregnancy rates. This means that the results do not refer to a single treatment cycle but to several back-to-back treatments (usually 3). As expected with such a faulty reporting system success rates can be significantly inflated.
People need to know that there are many factors that may affect the end outcome either positively or negatively”.
The most important of these variables are:
Age group of the patient:It is well known that as the female partner gets reproductively older the chances of success decline. This is because the egg quality is lower and as a result implantation rates may be severely affected. So, when reviewing a clinic’s results, you need to look at the age distribution of the population treated. Some clinics do not offer treatment to women of advanced age groups which leads to increased overall success rates. The ideal way to present data is per age group of the patients treated, so one can draw conclusions for the specific age group. Additionally, each group should include a relatively substantial number of treated women, so the results are statistically significant.
Number of embryos transferred:It has become an almost standard practice in our era to offer single embryo transfers, particularly in women of young age. The reason for doing so is to minimize the risk of a multi pregnancy which may negatively affect the reproductive outcome (delivery of a healthy baby). An elective single transfer policy can potentially determine success rates in different age groups. Clinics transferring many embryos might have higher success rates in terms of achieving a pregnancy but sometimes this comes along with a worse reproductive outcome (miscarriages, preterm deliveries etc.).
Preimplantation Genetic Testing (PGS) of the embryos:It is widely accepted that a substantial number of embryos could be genetically abnormal. Most of these embryos fail to implant following embryo transfer. So theoretically selecting genetically healthy embryos to replace back in the womb could improve the chances of conception. Wide adoption of this policy could, therefore, boost pregnancy rates in some cases. The downside of genetic testing is the increased risks of harming a healthy embryo during the process as well as the increased costs associated with the procedure. Clinics offering routinely PGS might report significantly higher pregnancy rates, particularly in women of older age groups.
Type of IVF treatment (own eggs vs donated eggs):If a woman is in her late 40s, the chances of conception following fertility treatment are quite low, but this applies only when using her own eggs. If the same woman has treatment with donor eggs, then the chances could be extremely higher. So, when reviewing results, it is of utmost importance to identify the type of treatment these results refer to. In cases of egg donation, the outcome may be affected even by the type of the donor eggs used (fresh vs frozen), as generally fresh donor eggs seem to perform better.
Interpreting success rates therefore can be a complicated process and involves an appreciation of the patient make-up of a clinic; the treatments it offers, and the variables used and applied. It would be wrong to suggest that clinic success rates are systematically massaged with the single intention of attracting larger patient flow but rather their interpretation should be undertaken with care. Ultimately, it is the patient, the consumer, the client who makes the final decision about the validity and relevance of the statistical claims made by the fertility clinic.
As Dr Dovas points out, “success rates should be transparent and reflect the age composition and general health of the patient; the treatments applied and the point at which measurements are taken”.
You can find the success rates Newlife Center of Reproductive Medicine here.
Its all in the Detail - In discussion with Dimitrios Dovas
October 18th, 2018
Success Rate and the IVF Sector
Andrew Coutts is in discussion with Dimitrios Dovas, Medical Director of Newlife Center of Reproductive Medicine, in Thessaloniki Greece
One of the most contentious issues in the fertility sector is the publication of clinic success rates. They have been the subject of celebration; doubt, and even incredulity amongst professionals, patients and the media.
It is however the interpretation of statistics rather than the statistics themselves which is key to the central discussion about whether they are a true and accurate representation of the work undertaken by a clinic. The same figures can be presented in different ways and consequently be interpreted very differently. The pertinent issue is whether the statistics we read are a result of subtle marketing or an out and out attempt to mislead.
Greece is a country that has a regulatory body place (National Authority of Human Reproduction) like the HFEA in the UK and SART in the USA, which is responsible for assessing the performance of IVF clinics as well as their reporting systems. All statistical data is subsequently reported annually to the European Society of Human Reproduction (ESHRE).