Babies born by C-section, fed formula milk are at higher risk of asthma

Researchers discover evidence that lead exposure in mothers can affect future generation
BABIES born by Caesarean section or fed formula milk are at a higher risk of asthma, scientists fear.

Researchers believe there is a link between key bacteria in a baby’s gut and their chances of developing the illness.

Those missing the bacteria – thought to be transferred from mother to child during birth or breastfeeding – at the age of three months were more than 20 times more likely to have been diagnosed with asthma at five.

It is believed exposure to these germs in the first months of life supercharges the immune system and helps prevent asthma from developing.

While it is not clear where the bacteria that protects from asthma come from, one possible route is a transfer from mother to child during a natural birth. It is also thought breast milk contains nutrients that help ‘friendly bacteria’ thrive.

Babies born by C-section or fed formula milk may therefore be lacking in them, the Canadian researchers said.

C-section rates are at record levels, with a quarter of British babies born this way. In some private hospitals the figure is as high as 50 per cent. Official figures also show that few women breastfeed exclusively for more than a few weeks.

Our high antibiotic use and ‘excessive’ cleaning may also play a role in killing key bacteria, the journal Science Translational Medicine reports.

This is known as the ‘hygiene hypothesis’, and suggests a bit of dirt helps strengthen our natural defences.

Meanwhile, a team of researchers at Wayne State University have discovered that mothers with high levels of lead in their blood not only affect the fetal cells of their unborn children, but also their grandchildren.

Their study, Multigenerational epigenetic inheritance in humans: Deoxyribonucleic Acid (DNA)/genetic material methylation changes associated with maternal exposure to lead can be transmitted to the grandchildren, was published online this week in Scientific Reports.

It is a known fact that babies in the womb can be affected by low levels of lead exposure. If a pregnant woman is exposed to lead, the lead passes through the placenta into the baby’s developing bones and other organs.

Pregnant women with a past exposure to lead can also affect the unborn child’s brain, causing developmental problems later in life. Previous research studies have suggested that exposure to heavy metal toxicants can influence a person’s global DNA methylation profile.

In the first study, scientists from the University of British Columbia, in Vancouver, tracked the health of more than 500 babies from birth until they turned five.
By analysing stool samples they found that children who did not have the bugs Faecalibacterium, Lachnospira, Veillonella and Rothia present in the gut at three months were 21.5 times more likely to have asthma aged five than those who did.

The team said it might be possible to work out which babies are at risk of the condition by testing them for these four bugs at a few months old.

Those deemed vulnerable could then be given the bacteria in the form of a probiotic drink.

Lead author Dr. Brett Finlay said: “It shows that gut bacteria play a role in asthma, early in life when the baby’s immune system is being established.”

Fellow researcher Dr. Stuart Turvey added: “This discovery gives us new potential ways to prevent this disease that is life-threatening for many children.”

Rosemary Dodds, of the National Childbirth Trust, said: “Asthma is a worrying and stressful condition … Newer areas of research such as gut bacteria and the ‘hygiene hypothesis’ show links to asthma but there is still a lot which needs to be understood and parents need to know what they can do now.”

You can have a natural birth after undergoing a C-section, say experts
Women who have had a Caesarean section can usually have a natural birth for subsequent babies, say experts.

Doctors have previously advised many C-section patients against trying for a natural birth the next time they have a baby.

But new guidance published by the Royal College of Obstetricians and Gynaecologists today says that a natural birth is the clinically safe choice for most women, and carries a lower risk of complications.

The report says that natural birth after a C-section has a success rate of around 75 per cent – the same as for first-time mothers. Even after two or more C-sections the success rate is still 71 per cent.

Lead author Professor Janesh Gupta, of Birmingham University, said: “Women can be assured that in most cases it is possible and safe to have a vaginal birth after a previous Caesarean section.”