Cesarean section delivery interferes with a baby's ability to obtain beneficial germs from the mother's microbiome, which can lead to early childhood asthma, said researchers at Rutgers University, the Copenhagen Prospective Studies on Asthma in Childhood, and the University of Copenhagen. The findings of the study are published in Science Translational Medicine.
The new study has implications for understanding C-section delivery's role in potentially skewing a child's microbiota and how this can influence health.
"Every generation of mothers hands over its microbiome to the next, as the baby is coated with beneficial germs while being squeezed through the birth canal - but this doesn't happen for babies born through C-section," said co-author Martin Blaser, director of the Center for Advanced Biotechnology and Medicine at Rutgers.
The effects of vaginal birth versus C-section during the first year of life for 700 children were analyzed by researchers. To determine whether the delivery type influences asthma risk, they examined children's fecal samples at one week, one month, and one year to determine microbial diversity and maturity.
The study revealed that C-section delivery was linked to more than a doubled risk of later asthma and allergies, as well as significant changes in the composition of the gut microbiota.
However, asthma risk was reduced in C-section-born children if their gut microbiota had recovered from its initial disruption and begun to mature normally.
"Even though a child is born by caesarean section and has an immense early microbial perturbation, this may not lead to a higher risk of asthma if the microbiome matures sufficiently before age 1 year," says Jakob Stokholm, senior scientist at The Copenhagen Prospective Study on Asthma in Childhood and the study's first author.
"Our study proposes the perspective of restoring a caesarean section-perturbed microbiome and thereby perhaps prevent asthma development in a child, who is otherwise at high risk."
Childhood Asthma Facts & Figures
- Asthma is one of the most common chronic childhood illnesses. It is more common in children than in adults.
- Childhood asthma is more common in boys than in girls.
- 1 in 13 people has asthma.
- 9 million US children under 18 have been diagnosed with asthma.