A child born through cesarean procedure or C-section is no more likely to develop obesity than those born through vaginal delivery, new research has found.
The findings contradict several smaller studies that did find an association between C-section deliveries and offspring obesity but did not consider the numerous maternal and prenatal factors that the researchers did in this study published in the journal PLOS Medicine.
"We found no evidence to support a link between C-sections and the development of obesity," said Daniel Berglind from Karolinska Institutet in Sweden.
"This tells us that how women give birth may not be an important factor in the origins of the global obesity epidemic," Berglind said.
Cesarean or C-section deliveries have soared in recent years, from 6.7 per cent globally in 1990 to around 19.1 per cent in 2014, according to earlier reports.
The jump has sparked intense research into the long-term consequences of C-section on offspring health.
The researchers in this study set out to investigate if indeed increased C-section births could explain part of the rise in obesity also seen in the last decades, and whether this potential association held true once they accounted for maternal and prenatal factors known to impact offspring weight.
They compared the body-mass index (BMI) of nearly 100,000 male 18-year-olds and divided them into categories depending on whether they were born through vaginal delivery, elective C-section or non-elective C-section.
According to the data, 5.5 and 5.6 per cent of the men delivered through elective and non-elective C-section, respectively, were obese compared to 4.9 per cent of the men delivered vaginally.
But after accounting for other factors known to impact offspring weight -- including pre-pregnancy BMI, maternal and gestational age and the presence of diabetes, hypertension, smoking and preeclampsia in the mother -- the researchers concluded that the method of childbirth did not play a significant role in determining the risk of obesity in the offspring.
The researchers also identified nearly 10,000 full brothers and concluded that sibling analysis, accounting for genetic and environmental factors, did not alter the overall findings.