(Press-News.org) An analysis of over 400,000 IVF cycles in the UK has shown that doctors should aim to retrieve around 15 eggs from a woman's ovaries in a single cycle in order to have the best chance of achieving a live birth after assisted reproduction technology.
The study, which is published online in Europe's leading reproductive medicine journal Human Reproduction [1], found that there was a strong relationship between live birth rates and the number of eggs retrieved in one cycle. The live birth rate rose with an increasing number of eggs up to about 15; it levelled off between 15 and 20 eggs, and then steadily declined beyond 20 eggs.
One of the authors of the study, Dr Arri Coomarasamy, said: "This is the first study to look at the association between the number of eggs and live births. Some smaller studies have reported previously on the association between egg numbers and pregnancy rates, but not live births. This is also the first study to devise a graph that can be used by patients and clinicians to estimate the chances of a live birth for a given number of eggs."
Dr Coomarasamy, a Clinical Reader and Consultant in Reproductive Medicine and Surgery at the University of Birmingham (UK), and his colleagues analysed data from the UK's Human Fertilisation and Embryology Authority (HFEA) on 400,135 IVF cycles that took place anywhere in the UK between April 1991 and June 2008. As live birth rates have steadily improved during this period, the researchers used data from 2006 to 2007 to create a predictive model that most closely reflected current practice. Using the model, they created a mathematical graph, called a nomogram, which shows the relationship between women's age, the numbers of eggs retrieved and the predicted live birth rate. Now patients and clinicians can use the nomogram when making decisions about the degree of ovarian stimulation required to achieve the optimum number of eggs for a live birth.
"Our data show that around 15 eggs may be the best number to aim for in an IVF cycle in order to maximise the chances of a live birth while minimising the risk of ovarian hyperstimulation syndrome (OHSS) which is associated with a high number of eggs, usually over 20," said Dr Coomarasamy. "Mild stimulation protocols aim to retrieve less than six to eight eggs; a standard stimulation should aim for 10-15 eggs, and we believe this is what is associated with the best IVF outcomes; when the egg number exceeds 20, the risk of OHSS becomes high." [2]
He believes that doctors could combine the use of the nomogram with current methods of measuring a woman's ovarian reserve in order to work out how much her ovaries need to be stimulated in order to retrieve 15 eggs in a safe manner.
"There are tests of ovarian reserve such as anti-mullerian hormone (AMH) and antral follicle count (AFC) which are good at predicting ovarian response and the egg yield following ovarian stimulation during IVF treatment. However, AMH and AFC are not good predictors of live birth rates. If clinicians use AMH or AFC to estimate the egg yield, they can then use our nomogram to convert this estimated number of eggs into a predicted live birth rate, thus completing the prognostic chain to estimate the chances of what both they and the women want: a live born baby."
The data also showed that during 2006-2007 the predicted live birth rate for women with 15 eggs retrieved was 40% for those aged 18-34, 36% for those aged 35-37, 27% for those aged 38-39 and 16% for women aged 40 and over.
Currently the HFEA collects data in a way that does not allow researchers to link information on IVF cycles using fresh embryos with IVF cycles using frozen embryos in the same woman. The authors of the study say that it is possible that this might alter the declining effect of higher numbers of eggs on fresh IVF cycles, because a woman has a greater chance of becoming pregnant if frozen embryos are available for transferring in subsequent cycles. However, "existing data suggest that the numbers of embryos frozen after a fresh IVF cycle are not enhanced by retrieving more than 18 eggs," write the authors.
Dr Coomarasamy said: "The HFEA have agreed to provide data linking fresh and frozen cycles to answer this research question and they may be releasing this information soon. By including the outcome following replacement of all frozen embryos generated from a single fresh IVF treatment, we could give an estimate of the cumulative live birth rate per IVF cycle. This is important information and we hope to gather the necessary data and report on this outcome in the future.
"None of this work would be possible without the support of the HFEA and we are very grateful to the staff there who validated these data."
###
[1] "Association between the number of eggs and live birth in IVF treatment: an analysis of 400 135 treatment cycles", by Sesh Kamal Sunkara, Vivian Rittenberg, Nick Raine-Fenning, Siladitya Bhattacharya, Javier Zamora, Arri Coomarasamy. Human Reproduction journal. doi:10.1093/humrep/der106
[2] Ovarian hyperstimulation syndrome (OHSS) is an excessive response by the ovaries in response to hormone drugs administered to stimulate the production of eggs for collection for IVF cycles. Mild and moderate OHSS causes abdominal pain, swelling and sometimes nausea and vomiting. In the rare, severe cases, it is a life-threatening medical emergency, with massive ovarian enlargement, fluid accumulation in the abdominal and pleural cavities, and risk of thrombosis.
15 eggs is the perfect number needed to achieve a live birth after IVF
2011-05-11
ELSE PRESS RELEASES FROM THIS DATE:
Drug regulators are protecting profits over patients, warn researchers
2011-05-11
Medicines regulators are protecting drug company profits rather than the lives and welfare of patients by withholding unpublished trial data, argue researchers on bmj.com today.
They call for full access to full trial reports (published and unpublished) to allow the true benefits and harms of treatments to be independently assessed by the scientific community.
Despite the existence of hundreds of thousands of clinical trials, doctors are unable to choose the best treatments for their patients because research results are being reported selectively, write Professor ...
RNA spurs melanoma development
2011-05-11
ORLANDO, Fla., May 10, 2011 –Traditionally, RNA was mostly known as the messenger molecule that carries protein-making instructions from a cell's nucleus to the cytoplasm. But scientists now estimate that approximately 97 percent of human RNA doesn't actually code for proteins at all. A flurry of research in the past decade has revealed that some types of non-coding RNAs switch genes on and off and influence protein function. The best studied non-coding RNAs are the microRNAs. Now, researchers led by Dr. Ranjan Perera at Sanford-Burnham Medical Research Institute (Sanford-Burnham) ...
McMaster scientists find protein’s bad guy role in prostate cancer
2011-05-11
Hamilton, ON (May 10, 2011) – It's a disease affecting those closest to us – our fathers, brothers and sons.
Prostate cancer impacts one in six men in Canada. Last year, roughly 24,600 men were diagnosed with the disease.
Most types of prostate cancer are curable if caught and treated early. But little is understood about the mechanisms that cause a tumour to metastasize and spread to other parts of the body.
Damu Tang, an associate professor of medicine in the Division of Nephrology of the McMaster University's Michael G. DeGroote School of Medicine and St. Joseph's ...
Successful depression treatment of mothers has long-term effects on offspring
2011-05-11
DALLAS – May 10, 2011 – Children whose mothers are successfully treated for depression show progressive and marked improvement in their own behaviors even a year after their moms discontinue treatment, new UT Southwestern Medical Center-led research shows.
Additionally, the faster mothers got better, the faster their kids improved – and the greater the degree of improvement experienced.
"If you treat the mother when she is depressed and don't even go through the process of treating the children of these mothers, they still get better as their mothers get better," said ...
CO2 makes life difficult for algae
2011-05-11
The acidification of the world's oceans could have major consequences for the marine environment. New research shows that coccoliths, which are an important part of the marine environment, dissolve when seawater acidifies.
Associate Professor Tue Hassenkam and colleagues at the Nano-Science Center, University of Copenhagen, are the first to have measured how individual coccoliths react to water with different degrees of acidity.
Coccoliths are very small shells of calcium carbonate that encapsulate a number of species of alga. Algae plays an important role in the global ...
Noted researcher addresses multiple dimensions of video game effects in new journal article
2011-05-11
AMES, Iowa -- Douglas Gentile is painfully aware of how research on the effects of video games on kids is often oversimplified to say that games are either "good" or "bad." The associate professor of psychology at Iowa State University has had his own research typecast on the "bad" side with studies on violent video game's effects and video game addiction, even though he's also done studies demonstrating the benefits of games.
A new article by Gentile appearing in the journal Child Development Perspectives argues that existing video game literature can't be classified ...
Wide-reaching report finds strong support for nurse and pharmacist prescribing
2011-05-11
Greater powers introduced by the government to enable specially trained nurses and pharmacists to prescribe medication in England have been successfully adopted, according to a new report.
Health service researchers from the universities of Southampton and Keele found widespread acceptance of the new powers among patients and that prescribing practices were safe and appropriate for the type of medical conditions being treated.
The Department of Health-funded report, published today (Tuesday, 10 May 2011), gives a national 'snapshot' of how successfully nurse and pharmacist ...
As good as gold
2011-05-11
Similar to humans, the bacteria and tiny plants living in the ocean need iron for energy and growth. But their situation is quite different than ours — for one, they can't exactly turn to natural iron sources like leafy greens or red meat for a pick-me-up.
So where does their iron come from? New research published by "Nature Geoscience" points to a source on the seafloor: minute particles (called nanoparticles) of pyrite, or fool's gold, from hydrothermal vents at the bottom of the ocean.
Scientists already knew the vents' cloudy plumes emitted from the earth's interior ...
It all depends on the coffee
2011-05-11
This release is available in French and German.
Capsule systems for making coffee are convenient and practical and therefore very popular. In terms of their environmental friendliness, however, a large question mark hangs over them. Roland Hischier, Empa's ecobalance expert, has just finished investigating various capsule systems as well as fully automatic machines, filter and soluble coffee making techniques, and has prepared a simplified life cycle analysis. This shows that it is the content which matters most. "A well-informed choice of coffee is in any case the ...
The sweet mysteries of the nervous system
2011-05-11
The antibody 5750 recognises a specific sugar residue on the cell surface, which is called LewisX. The research group lead by Prof. Dr. Andreas Faissner has now been able to use LewisX for the first time to separate different types of stem cells. The researchers report on their results in the Journal of Biological Chemistry.
Unexpected sugar diversity
Antibodies that recognise the LewisX sugar residue are used routinely to identify so-called neural stem cells from which the various cells of the nervous system originate. Prof. Faissner's team has now shown that the designation ...