Is your child overweight It could be because they were born by caesarean
12:06 GMT, 5 June 2012
Around one in four babies in England was born via caesarean in 2011. Under half the operations were for emergencies, the remainder were ‘elective’ — that is, planned.
Admittedly, many will have been for medical reasons such as breech birth, but could it be time to rethink our reliance on caesarean section as a routine form of delivery
Recent research from Harvard University and The Boston Children’s Hospital in the U.S. suggested babies born via caesarean had double the risk of childhood obesity.
Early indicator: Children born via caesarean have double the risk of becoming overweight, according to research by Harvard scientists (file picture)
In a study of more than 1,200 babies they found that 16 per cent of those delivered by caesarean (224) were clinically obese by the age of three compared with just 8 per cent of those who had a normal delivery.
They also had a higher BMI (Body Mass Index) and skin-fold thickness (another indicator of obesity) by that age.
With almost one in four reception pupils in the UK now either overweight or obese, the report attracted huge interest in the world of obstetrics.
‘While the majority of caesareans are carried out for valid medical reasons, there is a small group of women who, either because they are frightened of giving birth or because they feel that it is an easier way to have a baby, will request a section,’ says Sue McDonald, education and research manager at the Royal College of Midwives.
‘These women will have already been told by their obstetrician of the risks to themselves — that is, risk of infection, or long-term pain and scar tissue. This research gives us the opportunity to explain that a caesarean also potentially poses a risk to the long-term health of their baby,’ she adds.
‘This study certainly throws up some interesting findings,’ agrees Patrick O’Brien, an obstetrician and spokesperson for the Royal College of Obstetricians and Gynaecologists.
‘However, the actual amount of children in the study who were born by caesarean was actually quite small, so while we would certainly take notice we feel that more studies need to be carried out before we can confirm a definite link.
‘For the small amount of women we see who request a caesarean for reasons other than medical ones, findings such as these are certainly something we should let them know about.’
Problematic choice: A caesarean could pose a risk to the long-term health of a baby, providing another reason for mothers not to deliberately elect to have one
In fact, this is not the first study to link a caesarean with risks to a child’s long-term health. In 2008, researchers from Zurich found that babies delivered this way were 80 per cent more likely to be diagnosed with asthma than those who’d had a normal delivery.
And if they were also the offspring of parents who had asthma, they had a three times higher chance of contracting the condition.
The authors of that study suggested a natural birth in some way primed the baby’s immune system into action, a process that’s bypassed when the baby is removed directly from the womb.
But the researchers in the latest U.S. study go even further, linking the obesity increase to lack of exposure to ‘good bacteria’ which, they say, may be found in the vaginal wall.
It is known that babies born by caesarean have a greater number of a bacteria called Firmicutes, and lower levels of Bacteroides in their gut than babies born normally.
It is these two bacteria which make up some of the gut flora which are vital for the digestion of food.
‘It may be that gut bacteria influence the development of obesity by increasing energy extracted from the diet, and by stimulating cells to boost insulin resistance, inflammation and fat deposits,’ said the researchers.
However, other experts believe that this theory is simply a leap of faith with little solid evidence to back it up.
‘There is a theory that a certain type of gut bacteria can switch off or on a person’s ability to process foods,’ explains Dr Simon Campbell, a gasteroenterologist at the Spire Hospital Manchester and the Manchester Royal Infirmary.
‘However, gut bacteria content and counts are notoriously difficult to record and, so far, all the studies around this theory have been carried out on animals, and we are a long way from making any definitive claims. It is certainly not a theory that I would currently practise in my medicine.
‘In addition, there is no real evidence that any bacteria babies pick up as they go through the vaginal canal have any long-term effects on the health of the baby.
It may be that gut bacteria influence the
onset of obesity by increasing energy extracted from food,
and by stimulating cells to boost insulin resistance, inflammation and
In all likelihood any bacteria would be on the surface of the baby and very transitory at best.
‘There may well be other factors at work. The latest study noted that women who have caesareans are less likely to breastfeed their baby and breastfeeding is simply the best way of providing your baby with a healthy immune system and a robust digestive system,’ says Dr Campbell.
‘Having said that, this is an interesting theory and one that we should all be aware of and I, for one, would welcome more research into the issue.’
There is no doubt that the link between caesareans and the long-term health of the child is of increasing interest to scientists. In 2009 a team of Swedish researchers took samples from the umbilical cords of 37 newborn infants, 16 of whom were born by caesarean.
They found that in the days just after birth there were key changes to the chemistry of the DNA of the white blood cells that controlled the babies’ immune systems; this wasn’t seen in children delivered naturally, although after three to five days the difference was gone.
The researchers believe these changes may have been caused by stress levels, which are known to be higher in babies born by caesarean — labour gradually primes and prepares a baby for the outside world.
They also theorised that these short-term DNA changes could be the reason for the incidence of high asthma among caesarean babies, speculating these same changes could be the cause of cancer or diabetes in later life.
But while the scientists are trying to find out if there is a definitive link, others simply believe this latest news provides an excellent opportunity to assess our dependency on caesareans.
‘There is this completely inaccurate myth, sometimes perpetuated by TV shows and glamorous stars, that a caesarean is much easier on the body than natural birth, that you will be up and about within a few hours, as if nothing had happened,’ says Sue McDonald.
‘We already know that it is a major operation which requires long-term recuperation and can often have a long-term effect on the mother. Now we can see there may be a risk to the baby, too.
‘We are committed to reducing the rate of unnecessary caesareans, and maybe this research will give us another opportunity to do so.’