Children born by caesarean section are more susceptible to eczema and metabolic disorders including diabetes and obesity compared to those born through spontaneous vaginal birth, an Australian-led study shows.
The study of nearly half-a-million women and their children also found infants born with the help of forceps or vacuum extractor to a mother who was induced had the highest risk of jaundice and feeding problems.
Overall, the odds of serious respiratory infections, metabolic disorders and eczema were highest among children who experienced any form of birth intervention, according to the study published in the journal Birth on Monday.
Lead researcher Professor Hannah Dahlen, from Western Sydney University's School of Nursing and Midwifery, said the findings are concerning because these were low-risk, healthy women.
"The study adds to the mounting scientific evidence which suggests that children born by spontaneous vaginal birth, without commonly used medical and surgical intervention, have fewer health problems," she said.
Prof Dahlen stressed, however, this study was not designed to make women feel guilty but instead spark efforts to modify such outcomes for children born via interventions when necessary.
Western Sydney University collaborated with University Medical Center Groningen and VU Medical Center in Amsterdam, as well as South Australia's Flinders University, UCLAN University in Britain, Sydney University and the University College Cork in Ireland.
Researchers analysed health records of 491,590 women and their children born in NSW between 2000 and 2008.
The children's health was then followed during their first 28 days and up to five years of age, until 2013.
Prof Dahlen said a possible explanation for the study's findings was that physiological stress caused by birth interventions may alter the infants' genes that are linked to their immune response, known as epigenetic modulation.
Babies born via a caesarean section also miss out on good bacteria passed on during a vaginal birth that helps to "seed a healthy microbiome," she said.
"Also with caesarean section women always get antibiotics and that's having an impact going through to the baby and affecting the microbiome," Prof Dahlen said.
The gut microbiome is made up of the trillions of microorganisms and their genetic material that live in the intestinal tract.
Because of this, Dr Dahlen said she would like to see more research done on the use of probiotics.
Melbourne-based obstetrician, Dr Bernadette White said the findings do raise a lot of questions but women should not be concerned.
A member of the Royal Australian and New Zealand College of Obstetricians and Gynaecologists, Dr White doubts the research will change practice, although it may lead to a more thorough assessment of decisions taken during labour.
"Yes this paper does suggest that maybe there are some adverse consequences of trying to accelerate labour but you have got to weight that up against the benefits as well," she said.
Australian Associated Press
