"Couples can find out their chances of having a baby over multiple cycles of IVF treatment using a new online calculator," BBC News reports.
The calculator is designed to predict the success of in vitro fertilisation (IVF) – often used when a woman has a fertility problem – or intracytoplasmic sperm injection (ICSI), which is used when a man has a fertility problem.
Researchers used data from more than 100,000 couples in the UK. The data was recorded by the Human Fertilisation and Embryology Authority (HFEA), the regulator that oversees fertility treatments in the UK.
The researchers looked at several factors linked with the chances of a successful live birth, such as maternal age, the number of eggs collected, and the underlying reasons for treatment.
They used the models to create an online tool, which at the time of writing is available on the University of Aberdeen website.
It's hoped this tool will help couples make informed decisions, both emotionally and financially, about which treatment method may be right for them.
As the researchers themselves make clear in the study, there are significant gaps in the data the HFEA provided, such as the woman's body mass index (BMI), smoking status and history of alcohol use.
This means the model may not be able to reflect the many biological, health and lifestyle factors that can influence the likelihood of successful fertility treatment, or the fact every couple will have a different experience.
Where did the story come from?
The study was carried out by researchers from the University of Aberdeen in Scotland and the Erasmus MC-University Medical Centre in the Netherlands.
It was supported by a Chief Scientist Office postdoctoral training fellowship in health services research and health of the public research.
Generally, the UK media coverage was accurate, although the limitations of the "calculator" used by the researchers were not discussed.
What kind of research was this?
This modelling study aimed to develop a model that could predict the chances of a live birth over multiple cycles of in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI).
These are both assisted reproduction techniques. In IVF the egg is incubated with multiple sperm, while in ICSI a single sperm is injected directly into the egg.
ICSI may be the preferred option if there is less chance of fertilisation happening "naturally" – for example, if there are problems with sperm number, shape or movement.
The model used medical records from a UK population-based cohort study that collected data from couples who had undergone IVF or ICSI, including their biological characteristics and treatments.
Modelling studies like this one are useful for estimating potential outcomes, and could be helpful for both doctors and patients.
However, many different biological, health and lifestyle factors could influence the success of assisted reproduction, so this model may not necessarily be able to give definite answers.
What did the research involve?
Medical records of all complete IVF and ICSI cycles were collected from the Human Fertilisation and Embryology Authority (HFEA) in the UK.
The data used in this study was taken from 113,873 couples who started their first ovarian simulation between January 1999 and September 2008 using the woman's own eggs and partner's sperm, until exposure to IVF stopped in 2009.
Baseline characteristics included:
- woman's age
- duration of infertility (years)
- type of infertility (problems with the fallopian tubes, absent ovulation, endometriosis, male factor or unexplained)
- previous pregnancy status (yes or no)
- treatment type (IVF or ICSI)
- year of first egg retrieval
Treatment characteristics included:
- number of eggs collected
- number of embryos transferred
- stage of embryo transfer – either a cleavage transfer (two to three days after fertilisation) or a blastocyst transfer (five to six days after fertilisation)
- whether embryos were frozen
Using this information, the researchers estimated the cumulative chance of a couple having a first live birth after having up to six complete cycles of IVF.
They developed two models:
- a pre-treatment model for couples about to undergo IVF or ICSI
- a post-treatment model to update the cumulative probability of having a live birth after a first attempt at embryo transfer
What were the basic results?
Collectively, the 113,873 couples underwent 184,269 complete cycles of IVF or ICSI.
Just under a third of the women (33,154, 29%) had a live birth after their first cycle of treatment, and just over half (45,384, 56%) went on to have a complete second cycle of treatment.
Overall, 43% of the couples had a successful live birth over six complete cycles of IVF or ICSI.
In the pre-treatment model, the odds of a live birth decreased with every increasing complete cycle of treatment – the odds of a live birth after cycle two was 21% lower than the odds after cycle one.
The odds of a live birth after cycle six were 56% lower than the odds after cycle one.
As may be expected, odds also decreased with the increasing age of the woman, the length of infertility, male factor infertility, and in couples who had not had a previous pregnancy.
In the post-treatment model, after a fresh embryo transfer the odds of a live birth increased by 29% with the greater number of eggs collected.
This doubled in cases where frozen embryos were used. Odds decreased by 9% if ICSI was used.
How did the researchers interpret the results?
The researchers concluded: "We have estimated the individualised chances of having a live born baby over a complete package of in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI) treatment at two time points."
They added: "In couples embarking on IVF or ICSI, we found that increasing age of the woman (from 30 years) was far the best predictor of live birth.
"After transfer of a fresh embryo in the first complete cycle, aside from the woman's age, increasing number of eggs collected and the cryopreservation of embryos were the next best predictors."
This study aimed to develop a model that could predict the chances of a live birth over multiple cycles of in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI).
The model used a large quantity of data taken from reliable UK medical records belonging to couples who had previously undergone IVF or ICSI.
The model also benefits from being able to account for a large number of personal and treatment characteristics.
The researchers developed two models for couples in both the pre-treatment and post-treatment phase of treatment cycles.
They hope this online tool will serve as an aid for couples to shape expectations about what their overall chances are of having a baby after IVF or ICSI treatment, as well as allowing couples to make more informed decisions about their treatment.
Although this is potentially very useful for both doctors and patients, it's important to bear in mind that every couple will have a different experience – models, no matter how sophisticated, are not necessarily able to reflect what happens in reality.
And this tool includes very broad questions – for example, it asks if you have male factor infertility or tube problems. As such, it's not possible to add in your own specific data on factors like which fertility problem you or your partner may suffer from.
If you're considering having fertility treatment, you can increase your chances of conception – whether you're woman or man – by quitting smoking if you smoke, sticking to the recommended alcohol intake guidelines, and achieving or maintaining a healthy weight.
Analysis by Bazian
Edited by NHS Website
Links to the headlines
BBC News, 17 November 2016
Mail Online, 17 November 2016
The Daily Telegraph, 17 November 2016
The Sun, 17 November 2016
Links to the science
BMJ. Published online November 18 2016