C-section may have lasting effect on brain

Giving birth by caesarean section may reduce levels of a molecule vital to brain development in newborn babies, a controversial study has suggested.

Scientists found that natural birth triggered production of the protein UCP2 in the brains of infant mice.

Less of the protein was made in mice delivered by C-section.

UCP2, or mitochondrial uncoupling protein 2, is important for the proper development of brain circuits linked to memory, the researchers pointed out.

Blocking or knocking out the protein led to impaired brain function and behaviour in adult mice.

Other evidence suggested that induction of UCP2 by natural birth may help the transition to breastfeeding.

A leading British expert warned against making the “large leap” of assuming women might harm their babies’ brain development by having caesareans.

The research was carried out by a team of US scientists led by Tamas Horvath, chair of the Department of Comparative Medicine at Yale University.

Their findings were published in the online journal Public Library of Science ONE. Prof. Horvath delivered a stark message to women who had C-section births out of choice rather than for medical reasons.

He said: “These results reveal a potentially critical role of UCP2 in the proper development of brain circuits and related behaviours.

“The increasing prevalence of C-sections driven by convenience rather than medical necessity may have a previously unsuspected lasting effect on brain development and function in humans as well.”

In the UK, women who pay for expensive private treatment to give birth by C-section have been derided as “too posh to push”.

But Marian Knight, an honorary consultant in public health at Oxford University, was critical of the American research and said its findings should be viewed with caution.

“While this is an interesting laboratory study, the potential for human significance is far from established,” she said.

“The paper does not establish whether the change in the specific brain protein expression they note in mice which are delivered by caesarean section continues once the mice develop further, nor does the work investigate whether the mice delivered by caesarean section have developmental or memory problems as a consequence.

“The work establishes that mice which are genetically altered and completely lack the gene for the specific brain protein have behavioural differences from normal mice, but there is no link between the two halves of the study.”

Prof. Knight added: “The authors speculate that there may be significance for human development, however, this paper does not establish whether the observed changes have long-term consequences for mice let alone humans, and it is a largeleap to assume that this observed effect may have long-term consequences for babies.

“Women who are currently considering their choice of ways to give birth would be best advised to discuss their individual circumstances with their midwife or doctor alongside the known risks and benefits of caesarean or vaginal birth in humans when coming to a decision about what is best for them.”