Caesarean section, commonly referred to as C-section, is a surgical procedure used to deliver a baby through a surgical incision in the mother’s abdomen and uterus.

While this procedure has undoubtedly saved countless lives and is often necessary in certain medical circumstances, its increasing prevalence has raised concerns about potential long-term health effects.

The Rise of Caesarean Sections

The rates of caesarean sections have been steadily rising worldwide over the past few decades. According to the World Health Organization (WHO), the ideal rate for C-sections should be between 10-15% of total births.

However, many countries have far exceeded this threshold, with rates as high as 50% in some regions.

Association with Obesity

Several studies have suggested a potential link between caesarean section and a higher risk of obesity later in life.

A 2019 meta-analysis published in JAMA Pediatrics analyzed data from over 1.4 million individuals and found that those born via C-section had a 15% higher risk of developing obesity compared to those born vaginally. The reasons behind this association are not yet fully understood, but there are several hypotheses:.

Microbiome Disruption

During a vaginal birth, a newborn is exposed to the mother’s vaginal microbiota, which plays a crucial role in shaping the infant’s own gut microbiome.

The gut microbiome, composed of a diverse array of bacteria, is involved in various metabolic processes, including energy regulation. When a baby is born via C-section, they miss this important exposure, potentially leading to alterations in their gut microbiome and subsequent metabolic dysfunction.

Programming of Adipose Tissue

It has been suggested that the mode of delivery may influence the development and distribution of fat cells, particularly visceral adipose tissue.

Babies born via C-section may have a higher proportion of visceral fat compared to those born vaginally, which is associated with a greater risk of obesity and related comorbidities later in life.

Impact on Immune System

Birth through the birth canal exposes the infant to a wide range of maternal microbiota, which helps to prime their immune system and establish a healthy balance between immune tolerance and response to pathogens.

This natural exposure may be crucial for the development of immune-mediated disorders, such as asthma. C-section-born babies, lacking this exposure, may have an increased susceptibility to developing asthma and other allergic conditions.

Risk of Asthma

Asthma is a chronic respiratory condition characterized by inflammation and narrowing of the airways, leading to recurrent episodes of wheezing, shortness of breath, and coughing.

Multiple studies have found an association between caesarean section and an increased risk of asthma in childhood. A systematic review and meta-analysis published in the Journal of Allergy and Clinical Immunology in 2013 concluded that babies born via C-section had a 20-40% higher risk of developing asthma compared to those born vaginally.

Potential Mechanisms

Several mechanisms have been proposed to explain the observed link between C-section and asthma:.

Altered Microbial Exposure

As previously mentioned, the lack of exposure to the maternal vaginal microbiota during a caesarean birth may result in an altered colonization of the infant’s gut and respiratory tract, disrupting the development of a balanced immune system.

This dysbiosis could contribute to the development of asthma and other allergic diseases.

Immune Maturation

The mode of delivery can influence the immune maturation process in newborns. Babies born vaginally have higher levels of certain immune cells and cytokines, which play a critical role in immune regulation.

These differences in immune development may contribute to the increased risk of asthma in infants born via C-section.

Exposure to Antibiotics

C-sections are often accompanied by the administration of antibiotics, both prophylactically and due to infection-related complications. Prenatal and neonatal exposure to antibiotics has been associated with an increased risk of asthma.

It is hypothesized that these antibiotics may disrupt the infant’s gut microbiota or directly affect immune regulation, contributing to the development of asthma.

Socioeconomic Factors

Although much research has been conducted to explore the possible biological mechanisms underlying the association between C-sections and asthma, it is important to consider the potential influence of socioeconomic factors.

Mothers who undergo planned or elective C-sections often differ from those who undergo emergency C-sections or vaginal deliveries in terms of various social and environmental factors, such as education level, access to healthcare, and lifestyle choices, all of which could independently contribute to the observed association.

Conclusion

While caesarean sections are sometimes medically necessary and life-saving procedures, the increasing rates of C-sections raise concerns regarding their potential long-term health effects.

Mounting evidence suggests an association between C-section and an increased risk of obesity and asthma. However, further research is needed to better understand the underlying mechanisms and determine causality definitively.

It is essential to strike a balance between the benefits and risks associated with caesarean sections, considering both maternal and neonatal health outcomes.