Thursday, May 30, 2013
Obesity risk for C-section babies: 84% more likely to be overweight than children born naturally
Less healthy women probably have more C-sections and it is the prior health of the mother that influences obesity, not the C-section
Babies born by caesarean section are almost twice as likely to be overweight as children and teens, according to a new study.
After examining the health records of more than 10,000 British children, researchers found that surgically delivered 11-year-olds were 83 per cent more likely to be overweight compared to those born naturally.
The results of the study confirm previous research that also found a link between caesareans and childhood obesity.
Researchers believe that babies by natural childbirth are exposed to bacteria in the birth canal which helps regulate metabolism in later life.
The findings suggests the obesity epidemic could in part be driven by increasing rates of caesareans. The rate in England stands at one in four births, which totals more than 160,000 a year.
Health concerns often dictate whether a women undergoes surgical delivery, which can be life-saving for both mother and child, but in many cases there is no medical reason for the operation.
‘There may be long-term consequences [of caesareans] to children that we don’t know about,’ said lead researcher Dr Jan Blustein, from the New York University School of Medicine.
She said the extent of the obesity risk for children is ‘not great’ and should not be a factor when considering whether a women should have the operation for medical reasons.
The team looked at data from a major investigation of childhood development called the Avon Longitudinal Study of Parents and Children. This tracks the long-term health and well-being of around 14,000 children born in the early 1990s.
Just over nine per cent of the children in the study were born by caesarean, and on average were two ounces lighter than those delivered naturally.
But by the age of six weeks, those surgically delivered were consistently heavier than their naturally-born counterparts at almost all points - even when other factors such as their mother’s weight and whether they were breastfed were taken into account.
The risk of obesity was particularly marked among children born to overweight mothers, the researchers said.
In total, a third of all the three-year-olds in the study were overweight, while at the age of seven and 15 there was a 17 per cent chance of a child being obese.
The research, published in the International Journal of Obesity, also highlighted the risks to women of undertaking a caesarean including increased chance of bowel or bladder injuries as well as future pregnancy complications.
Dr Blustein said one reason for the link between caesarean’s and obesity could that these infants are not exposed to beneficial bacteria in the birth canal, and therefore their bodies take longer to accumulate good bugs that boost the body’s metabolism.
Obese adults tend to have fewer ‘friendly’ bacteria in their digestive tract and higher levels of ‘bad’ bacteria, which mean they burn fewer calories and store more of them as fat.
However, other studies show that obese women are more likely to need a caesarean, and are more likely to have children who grow up to be overweight or obese.
‘The other possibilities are (that) these are children that would have been heavier anyway,’ Dr Blustein said. ‘Being heavy as a woman is a risk factor for C-section, so that’s the problem with trying to figure out whether this is real or if it’s simply a matter of selection.’
An end to annual flu injections? Scientists develop new 'universal' jab against all strains of influenza which could last a lifetime
Let's hope it works
A new type of vaccine has been developed which could provide long-term protection and last a lifetime against all types of influenza.
The 'universal' vaccine targets part of the virus common to all strains, meaning it could provide a way around the problem of the bug frequently mutating and making preventative treatment ineffective.
It was created by a team working for U.S. healthcare company Sanofi using techniques that have also raised hopes of a new generation of vaccines against other diseases.
The study has been published in the journal Nature.
Team leader Gary Nabel said: 'This structure-based vaccine improves the potency and breadth of influenza virus immunity, and it provides a foundation for building broader vaccine protection against emerging influenza viruses and other pathogens.'
Influenza kills between 250,000 and 500,000 globally per year, according to the World Health Organisation.
Earlier this month experts warned a deadly bird flu virus sweeping through China had taken the first steps towards becoming a global threat to human populations.
In the space of one month, the avian strain known as H7N9 spread through all 31 Chinese provinces and claimed 125 victims, killing a fifth of those infected.
Scientists say it is mutating rapidly and already has two of five genetic changes believed to be necessary for human-to-human transmission.
Currently the virus has made its home in chickens, and only affected people who have had close contact with the birds, often at live markets.
The Sanofi team's vaccine is built using protein 'self-assembling nanoparticles', which when injected create antibodies that attach themselves to parts of the virus that are common to different strains.
In lab tests on ferrets, which can suffer the same strains of flu as humans, it was more potent and affected more strains than the current licensed vaccine, the team said.
It is also safer to make than standard vaccines, which are produced by growing the virus in a lab.
The DIY way it is made means similar methods could be used to create vaccines against other diseases.
Scientists gave a cautious welcome to the research, but said trials on humans were needed to see if it worked as well as hoped.
Professor Wendy Barclay, chair in influenza virology at Imperial College London, said the research targeted a 'soft underbelly of the virus'.
'In short this paper takes us a step closer to believing that a universal flu vaccine is possible, by thinking outside of the box in terms of how to synthesise and manufacture flu vaccines,' she said.
'What's more this route could be faster, cheaper and safer than the one we usually use.'
Professor Sarah Gilbert, professor of vaccinology at the University of Oxford, added:
'There's no indication as to whether any clinical trials are planned, and since this is a new type of vaccine it might be some time before they could start.
'So at the moment it's an interesting development in the lab, with some novel aspects, but definitely not a universal influenza vaccine and it needs to be tested in clinical trials before we get too excited.'
Posted by jonjayray at 12:05 AM