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Call for debate on freezing IVF embryos

Should embryos be frozen before IVF ?
Fertility doctors have called for a debate around whether freezing embryos should become the main option for IVF treatment in the future.Main Story
An analysis of 13,000 IVF pregnancies suggested the freezing process might be better for the mother and the baby's health.
However, some fertility specialists argue there would be fewer pregnancies if freezing was more widely used.
The study's findings were presented at the British Science Festival.
IVF treatment Most of the time in IVF clinics in the UK, eggs are taken, fertilised and the resulting embryos implanted. This is thought of as using fresh embryos.
However, about one in five cycles of IVF in the UK uses frozen embryos - these were "spare" embryos kept from a previous IVF attempt.
There have been concerns that freezing may pose a health risk. However, the latest analysis, which is also published in the journal Fertility and Sterility, suggests that freezing may have better results.
It reported a lower chance of haemorrhage, premature birth and deaths in the first few weeks of life.

'Debate now'
Lead researcher Dr Abha Maheshwari, from the University of Aberdeen, said: "Our results question whether one should consider freezing all embryos and transfer them at a later date rather than transferring fresh embryos."
She told the BBC more research was needed and that it was "a controversial topic". "It is a debate we should be having now," she added. "It needs further exploration about what we do in the future."
Why frozen embryos might have better results is unknown and the researchers acknowledge the results are "counter-intuitive".
One theory is that stimulating the ovaries to release more eggs, as part of normal IVF may affect the ability of the womb to accept an embryo. Freezing the embryo until later would allow it to be implanted in a more "natural" womb.

Fewer births
However, data from the Human Fertilisation and Embryology Authority says that in 2010 frozen embryos were less likely to result in pregnancy. There was a 23% success rate for frozen and a 33% chance for fresh embryos.
Dr Maheshwari argues that new techniques in the past few years have greatly increased the success rate. .
However Prof Alison Murdoch, the head of the Newcastle Fertility Centre at Life, Newcastle University, said: "It is of some concern that conclusions have been drawn, incorrectly, that we should routinely freeze all embryos and transfer them in a future menstrual cycle. .
"There is ample evidence to show that this would result in fewer pregnancies even if the outcome for those pregnancies were better."
The director of IVF at Hammersmith Hospital in London, Stuart Lavery, said it would be "incorrect to conclude from these findings that we should stop performing fresh transfers and freeze all embryos".
However Mr Lavery said it provided reassurance that frozen embryos were as safe as fresh ones. .
It was a view shared by Dr Allan Pacey, the chairman of the British Fertility Society and a researcher at the University of Sheffield.
He said: "I think this is interesting because some people are nervous about frozen embryos and there have been various headlines about this study or that which suggest that frozen embryos may be a worry.
"What's really useful is that it shows that from the point of view of the woman's health during labour, and some early measures of the baby's health, frozen embryos do all right and are arguably better."

Frozen embryos' health benefit


More evidence has emerged that babies born from frozen embryos are healthier than those that develop from fresh embryos, researchers say.
Three studies presented to a US fertility conference found frozen embryo babies were less likely to be premature and under weight.
Previous research has suggested this is down to only the strongest embryos surviving the freezing process.
Fertility experts said more work was needed on the issue.
A Finnish study, to be presented to the American Society for Reproductive Medicine meeting in San Francisco, found that babies born from fresh embryos were 35% more likely to be premature and 64% more likely to have low birthweight than those born from frozen.
A second study, from the University of Pennsylvania in Philadelphia, found that babies born from fresh embryos were 51% more likely to have low birthweight and were 15% more likely to die around the time of birth than those born from frozen embryos.
And research by the Royal Women's Hospital in Melbourne, Australia, found 11% of babies born from fresh embryos had low birthweight compared with 6.5% of babies born from frozen.
A total of 12.3% of babies born from fresh embryos were premature, compared with 9.4% of those born from frozen, while 1.9% also suffered death compared with 1.2% from frozen.

It is thought the results were related to the quality of the placenta, the digestive and respiratory system for the foetus.
The Australian researchers said the findings suggested women may prefer to use frozen embryos in the future.
But Dr Allan Pacey, a fertility expert from the University of Sheffield and secretary of the British Fertility Society, warned it was not so clear cut.
"Frozen embryo transfers are not as successful as fresh ones in terms of getting a pregnancy.
"So it may be that we have to balance the health of children against chances of success."
But he added: "It is intriguing research that goes against what we would normally assume. It now needs to be looked at again."

Longest frozen embryo baby born


A healthy baby girl has been born in the US after spending the last 13 years in frozen suspension as an embryo.
This is thought to be the longest an embryo has been frozen and resulted in a healthy baby.
Baby Laina Beasley has two teenage siblings who were conceived through IVF at the same time as she was frozen, which technically makes her a triplet.
Her parents' path to having her was far from smooth, highlighting the risks of a largely unregulated industry.

Set backs
When Debbie Beasley, now 45, began her fertility treatment in at the University of California Irvine Center in the 1990s, the doctors used her eggs and her husband Kent's sperm to make 12 embryos.
Debbie had three embryos transferred to her womb and became pregnant with triplets, but lost one halfway through her pregnancy.
Twins Jeffrey and Carleigh were born in 1992.
Three years later, they discovered their fertility doctor, Dr Ricardo Asch, and his colleagues were accused of taking eggs and embryos from parents without telling them and implanting them in other women or sending them to outside scientists for research.
The clinic was shut down and Dr Asch left the US.
Debbie and Kent were told that some of their remaining embryos had been send to an East Coast university for experiments. They managed to track down eight.
In the summer of 1996, Debbie and Kent decided they wanted to try to have another baby using the frozen embryos.
They were told that the chances of success were about 20% or one in five - about half don't survive the thawing process and of those that do, many do not thrive once in the womb.
Debbie had two of the frozen embryos thawed for transfer. However, she had a severe reaction to a fertility drug and went into shock and nearly died. The two thawed embryos perished.
It wasn't until seven years later that she felt well enough to try for a baby again. Last June, with the help of Dr Steven Katz and colleagues at the Fertility Associates of the Bay Area in San Francisco, Debbie and Kent had their six remaining embryos thawed.
Four appeared to have survived and one looked perfect. All four were transferred to Debbie's womb.
In an interview with the San Francisco Chronicle, Debbie said: "I put my hand over my lower abdomen and said, 'Welcome Home'. They had been in a cold place for so long. Now it was over. Whether God took them to heaven or they became babies, it was OK."
One of the embryos did become a healthy baby - Lania - even though she was born five weeks early.
Debbie said: "I still look at her and can't believe it. I smell her and kiss her and I still can't believe she is here."

Fertility laws
There are many differences between the US and the UK in terms of fertility laws and practice.
In the UK, frozen embryos are typically stored for only five years and sperm and egg for 10 years. These storage periods can be extended in extenuating circumstances, for example if a couple's fertility problems are particularly severe.
Also, written consent is required from both the man and the women for the use and storage of their sperm, eggs and any resultant embryos.
This consent can be changed at any time as long as the sperm, eggs or embryos have not been used.
A spokeswoman from the Human Fertilisation and Embryology Authority said: "It is about effective informed consent so that the people involved understand the full implications."
UK clinics also put a limit on the number of embryos that can be transferred into a woman's womb at one time - a maximum of two at a time for those under the age of 40 and three for those over 40.
This is to avoid health complications associated with multiple births for both the mother and the babies

Frozen embryos 'better for IVF'


Frozen is better than fresh when it comes to transplanting embryos in IVF treatment, a study shows.
Danish scientists found babies born after a frozen embryo was thawed and implanted had higher birth weights than those born from fresh embryos.
The study of over 19,000 babies also found no added risk of birth defects.
A European fertility conference heard frozen embryo babies did better because only the most robust embryos survived the freezing and thawing process.
Freezing embryos allows couples to have several cycles of treatment from one egg collection.
That means it cuts the amount of times women have to take ovarian stimulation drugs.

Single embryos
As doctors want to avoid multiple pregnancies, it is common for just one embryo - which has been fertilised in the lab - to be transferred into the womb, and the rest frozen.
In later cycles, a frozen embryo is thawed and implanted three to five days after ovulation, exactly the same way as fresh embryos are used.
While single embryo transfers are becoming increasingly common, the researchers said there was little data on the results of using frozen embryos.
But earlier mouse studies had shown a higher rate of behavioural and development problems in animals born from frozen embryos.
In this study, presented to the European Society for Human Reproduction and Embryology meeting in Barcelona, all 1,200 babies who had been born from frozen embryos between 1995 and 2006 in Denmark were compared to the 17,800 babies born from fresh embryos.
The data showed no increase in the rate of congenital malformations - which include conditions such as spina bifida and cleft palate.
Fewer frozen embryo babies were admitted to neonatal care units, but the researchers said this was probably because there was a higher rate of multiple births in the fresh embryo group.
In addition, pregnancies lasted slightly longer in the frozen embryo group, and babies were an average around 200 grams bigger.
There were also a lower proportion of low-birth weight babies weighing under 2,500 grams (5.5lbs) and fewer premature births, before 37 weeks.

Dr Anja Pinborg, who led the research, said: "We think the reason for the differences is probably positive selection of the embryos for frozen embryo replacement.
"Only the very top quality embryos survive the freezing and thawing process.
"And you only get pregnancies in patients with lots of good embryos to freeze."
She added that by the ovarian stimulation patients have to go through in order to get fresh embryos could negatively influence a consequent pregnancy - something women using frozen embryos would not be affected by.
Dr Pinborg said: "The findings are reassuring.
"If our results continue to be positive, it can be accepted as a completely safe procedure, which can be used more frequently than it is currently."

IVF: Frozen embryo babies heavier and healthier – study


IVF couples can store frozen embryos for use at a later stage Main story
IVF babies born from frozen embryos are heavier and result in longer pregnancies than those born from fresh embryos, research suggests.
A study presented at the British Fertility Society annual meeting says transferring frozen embryos may lead to healthier babies.
But the reasons behind the findings are unclear, the researchers say.
All the babies were single births, with no twin or triplet pregnancies included in the study.
The study, carried out at the Centre for Reproductive and Genetic Health in London, involved measuring the weight and length of gestation of 384 babies born after fresh embryo transfer and 108 born after frozen embryo transfer.
Freezing embryos enables couples to have several cycles of IVF with eggs collected during one round of treatment.
By freezing some embryos, couples can use up their fresh ones before moving on to frozen ones at a later date.
The results of the study showed that babies born from frozen embryos were, on average, 253g (0.56lb) heavier than those born from fresh embryos.

This means that resulting babies may potentially be healthier if frozen embryos are transferred rather than fresh embryos”
Suzanne Cawood Centre for Reproductive and Genetic Health
The proportion of low birthweight babies (weighing less than 2.5kg) was also lower in this group - 3.7%, compared with 10.7% of babies born from fresh embryos.
Frozen embryo babies typically had a longer gestation period (an average of 0.65 weeks longer) than those born from fresh embryos, the research also found.

'One at a time'
Lead researcher Suzanne Cawood, deputy head of embryology at the Centre for Reproductive and Genetic Health in London, said the study was important because prematurity and low birthweight were both risk factors for poorer health in later life.
"This means that resulting babies may potentially be healthier if frozen embryos are transferred rather than fresh embryos.
"The reasons behind these findings are not yet fully understood, but one possibility may be that there is a difference in the uterine environment between fresh cycles, when embryos are transferred soon after the eggs have been collected, compared to frozen cycles when the uterus has not been stimulated in the days before transfer."
But she said further research was needed to test the hypothesis.
Infertility Network UK chief executive Clare Lewis-Jones said the new study supported the move to transferring only one embryo at a time.
This cuts down the multiple pregnancy rate - which is higher in IVF than natural conception - with health benefits for mother and baby.
She said: "These initial findings, if proved accurate following further research, will give the medical profession more evidence to encourage patients to accept single embryo transfer, which reduces the risks of multiple births to both mother and babies.
"Single embryo transfer gives the best possible outcome - a healthy singleton baby - with the chance of further frozen embryo transfers in the future."