Caesarean section and obesity in young adult offspring: Update of a systematic review with meta-analysis

Perinatal risk factors and disordered eating in children and adolescents

OBJECTIVE

Studies have reported associations between perinatal factors (obstetric and neonatal factors) and later eating disorder risk. However, previous findings have been partly conflicting. Here, we analyzed associations between perinatal factors and disordered eating in a large cohort of Finnish children and adolescents.

METHOD

The participants were 8- to 14-year-old children and adolescents (N = 11,357) from The Finnish Health in Teens study. Disordered eating was assessed using the Children's Eating Attitudes Test (ChEAT). Perinatal data were obtained from the Finnish Birth Registry. Perinatal variables were initially analyzed using Chi-square analyses and linear regressions. Variables associated with disordered eating (p < .10) were entered into a multinomial logistic regression model. The regression analysis was conducted both including and excluding maternal BMI, as this information was missing for > 80% of the participants.

RESULTS

Of the participants, 56.6% reported disordered eating (ChEAT score ≥ 11) or partial disordered eating (1-10) symptoms. Including maternal BMI in the analyses (n = 1921), higher levels of disordered eating were independently associated with maternal pre-pregnancy BMI (OR 1.07, 95% CI [1.02, 1.12]), maternal smoking during pregnancy (OR 2.64, 95% CI [1.49, 4.68]), urgent or emergency cesarean birth (OR 2.16, 95% CI [1.10, 4.05]). Assisted reproduction was associated with lower levels of disordered eating (OR 0.39, 95% CI [0.20, 0.76]).

DISCUSSION

The results suggest that pregnancy and childbirth are vulnerable developmental periods, associated with later eating pathology. Further studies disentangling genetic and environmental mechanisms of associations between perinatal factors and later eating pathology are needed.

LEVEL OF EVIDENCE

Level III, Evidence obtained from well-designed cohort or case-control analytic studies.

Parental high-fat diet induces upregulation of macrophage receptor with collagenous structure expression and exacerbates colorectal inflammation via the nuclear factor kappa-B pathway in offspring

Parental high-fat diet (HFD) increases offspring's susceptibility to colorectal inflammation, but the underlying mechanism remains unclear. Using mouse models, we compared colorectal inflammation between offspring of HFD-fed and normal diet-fed parents. Histological analysis and immunostaining revealed that offspring of HFD-fed parents exhibited shortened colorectal length, decreased goblet cells, and reduced tight junction protein expression, particularly when maintained on HFD. RNA sequencing of colorectal tissue identified elevated expression of macrophage receptor with collagenous structure (MARCO) in these offspring. Immunofluorescence co-localization staining confirmed increased MARCO-positive macrophages in their colorectal tissue. Notably, switching offspring to normal diet partially alleviated these inflammatory responses, although some manifestations remained. Further investigation showed that high-lipid stimulation increased MARCO expression in macrophages and promoted inflammatory cytokine secretion through nuclear factor kappa-B (NF-κB) pathway activation. In vitro experiments demonstrated that MARCO knockdown inhibited the expression of inflammatory cytokines and prevented tight junction protein destruction in cocultured intestinal cells. Our findings reveal that parental HFD induces MARCO upregulation in offspring's colorectal macrophages and exacerbates colorectal inflammation through the NF-κB pathway, providing new insights into the mechanism by which parental HFD affects offspring's intestinal health.

Gut Microbiota: An Important Participant in Childhood Obesity

Increasing prevalence of childhood obesity has emerged as a critical global public health concern. Recent studies have challenged the previous belief that obesity was solely a result of excessive caloric intake. Alterations in early-life gut microbiota can contribute to childhood obesity through their influence on nutrient absorption and metabolism, initiation of inflammatory responses, and regulation of gut-brain communication. The gut microbiota is increasingly acknowledged to play a crucial role in human health, as certain beneficial bacteria have been scientifically proven to possess the capacity to reduce body fat content and enhance intestinal barrier function and their metabolic products to exhibit anti-inflammatory effect. Examples of such microbes include bifidobacteria, Akkermansia muciniphila, and Lactobacillus reuteri. In contrast, an increase in Enterobacteriaceae and propionate-producing bacteria (Prevotellaceae and Veillonellaceae) has been implicated in the induction of low-grade systemic inflammation and disturbances in lipid metabolism, which can predispose individuals to obesity. Studies have demonstrated that modulating the gut microbiota through diet, lifestyle changes, prebiotics, probiotics, or fecal microbiota transplantation may contribute to gut homeostasis and the management of obesity and its associated comorbidities. This review aimed to elucidate the impact of alterations in gut microbiota composition during early life on childhood obesity and explores the mechanisms by which gut microbiota contributes to the pathogenesis of obesity and specifically focused on recent advances in using short-chain fatty acids for regulating gut microbiota and ameliorating obesity. Additionally, it aimed to discuss the therapeutic strategies for childhood obesity from the perspective of gut microbiota, aiming to provide a theoretical foundation for interventions targeting pediatric obesity based on gut microbiota.

Characterization of newborn gut microbiota according to the pre-gestational maternal nutritional status and delivery mode

PURPOSE

The aim of this study is to characterize the composition of the newborn gut microbiota based on the maternal pre-pregnancy nutritional status and the delivery mode.

METHODS

A biological sample was collected from the anal mucosa of the newborns between 24 and 48 h after delivery, as it was not possible to collect a meconium sample at that time. A general data collection questionnaire was administered. The microbiome of the samples was analyzed by next-generation sequencing of the hypervariable regions v3-v4 of the 16S gene. Alpha diversity analyses were performed using the Observed Richness and Shannon diversity index metrics and Beta diversity analyses were conducted using Nonmetric multidimensional scaling with Weighted Unifrac, Differential abundance analysis was performed using a Negative Binomial Wald Test with maximum likelihood estimation for coefficients of Generalized Linear Models.

RESULTS

Newborns of obese mothers exhibited lower alpha diversity compared to newborns of mothers with adequate BMI (body mass index). We observed variation in the composition of the microbial community in newborn stool samples, both from mothers with overweight/obesity and those with adequate pre-pregnancy BMI. We observed a visible correlation between the mode of delivery and the newborn's microbiota. We found variation in the overall composition of the microbial community in the stools of newborns, regardless of the delivery mode.

CONCLUSIONS

The results of our study demonstrate differences in the microbiota of neonates born via cesarean section compared to those born vaginally as well as differences in newborns of mothers with overweight/obesity compared to those with an adequate pre-pregnancy BMI.

Caesarean section and risk of infection in offspring: systematic review and meta-analysis of observational studies

Objective

To compare the risk of hospital admissions with infections and infections not in hospital in children born by caesarean section with children born by vaginal birth.

Data sources

Medline, Embase, and PubMed were searched with no restriction on start date up to 12 February 2024.

Study selection

Observational studies were included that reported the association between caesarean section and vaginal birth in relation to the risk of infections (both those that lead to hospital admission and those that do not) up to 18 years of age. Studies were excluded if they were not representative of a general population or if they focused on congenital, neonatal, or vertically acquired infections. No restrictions were made for language, publication date, or setting.

Review methods

Findings for hospital admissions with infection were synthesised by meta-analyses of specific infection outcomes and type of caesarean birth (emergency v elective) and findings for other infections (ie, infection episodes reported by parents and primary care visits) by direction of effect. Risk of bias was assessed using the ROBINS-E tool and the overall certainty of evidence through the GRADE framework.

Results

31 eligible studies of over 10 million children were included. Findings were from population-based birth cohorts and registry data linkage studies in high income countries. Cohort sizes ranged from 288 to 7.2 million and follow up age was from one to 18 years. Outcomes included overall and specific clinical categories of infection. From studies of overall admission to hospital with infection, the proportion of children admitted ranged between 9-29% across exposure groups. In random-effects meta-analyses combining hazard ratios, children delivered by caesarean section had an increased rate of hospital admission with infections overall and in three common clinical infection categories: (1) overall admissions to hospital with infection (emergency caesarean section: n=6 study populations, hazard ratio 1.10 (95% confidence interval 1.06 to 1.14), τ 2=0.0009, I2=96%; elective caesarean section: n=7, 1.12 (1.09 to 1.15), τ 2=0.0006, I2=88%); (2) admission to hospital for upper respiratory infections (emergency caesarean section: n=7, 1.11 (1.09 to 1.13), τ 2=0.0003, I2=73%; elective caesarean section: n=7, 1.16 (1.12 to 1.20), τ 2=0.0012, I2=89%); (3) admission to hospital for lower respiratory infections (emergency caesarean section: n=8, 1.09 (1.06 to 1.12), τ 2=0.0010, I2=88%; elective caesarean section: n=8, 1.13 (1.10 to 1.16), τ 2=0.0009, I2=84%); (4) admission to hospital for gastrointestinal infections (emergency caesarean section: n=7, 1.19 (1.13 to 1.26), τ 2=0.0025, I2=86%; elective caesarean section: n=7, 1.20 (1.15 to 1.25), τ 2=0.0009, I2=67%). Eight of 11 studies of other infections suggested an increased risk of their primary infection outcome in those born by caesarean section. Risk of bias concerns primarily related to confounding.

Conclusions

Findings from high income countries showed a consistent association between caesarean section birth and greater risk of infections in children across various settings. Limitations of existing studies include the potential for unmeasured confounding, specifically confounding by indication, and a scarcity of studies from low and middle income countries.

Review registration

PROSPERO (CRD42022369252).

Is There an Association Between Cesarean Section Delivery with Specific Learning Disabilities (SLD) or/and Attention-Deficit/Hyperactivity Disorder (ADHD)? A Cross-Sectional Study in Greek Population

BACKGROUND/OBJECTIVE

Learning difficulties (LDs) are lifelong neurodevelopmental disorders with multifactorial causes, including perinatal factors like mode of delivery. This study aims to explore whether cesarean section (CS) delivery is linked to the occurrence of specific learning disabilities (SLDs), attention-deficit/hyperactivity disorder (ADHD), or their comorbidity.

METHODS

An online questionnaire was distributed via Google Forms to Greek mothers and parents of children with and without diagnoses, shared through school-related groups and various Greek pages focused on child development, special education, and learning difficulties. Conducted over eight months (October 2023-May 2024), this cross-sectional study involved 256 children, 137 with LDs diagnoses, and 119 controls.

RESULTS

In total, 59.9% of CS-born children had a diagnosis, compared to 40.1% of those born vaginally (X²(1) = 4.19, p = 0.045). CS delivery was associated with a 68% increased likelihood of LDs (OR = 1.68, 95% CI [1.02, 2.76]), with higher risks for ADHD (OR = 2.25, 95% CI [1.06, 4.79]) and comorbid SLD/ADHD diagnoses (OR = 2.75, 95% CI [1.17, 6.46]). Stratified analyses showed birthweight and gestational age as effect modifiers rather than confounders. Key postnatal risk factors identified were family history (OR = 4.65, 95% CI [2.41, 8.94]) and language acquisition difficulties (OR = 5.28, 95% CI [1.36, 20.47]).

CONCLUSIONS

The findings suggest a possible association between CS and LDs, along with a novel link between CS and increased comorbidities. These results underscore the need for further research and provide valuable insights into how CS delivery may influence the risk of LDs, depending on the type of diagnosis.

Risk of Asthma and Allergies in Children Delivered by Cesarean Section: A Comprehensive Systematic Review

BACKGROUND

It is unclear whether cesarean delivery increases the risk of allergic diseases in offspring.

OBJECTIVE

To investigate the association between cesarean delivery and the risk of allergic diseases in offspring.

METHODS

We searched PubMed, Embase, and the Cochrane Library for relevant studies up to October 12, 2023. Observational studies comparing the risk of allergic diseases in offspring delivered by cesarean section versus those delivered vaginally were included. Most-adjusted estimates from individual studies were synthesized by meta-analysis.

RESULTS

A total of 113 studies were included, 70 of which had a low risk of bias. Compared with offspring delivered vaginally, offspring delivered by cesarean section had significantly greater risks of asthma (odds ratio [OR] = 1.20; 95% CI, 1.16-1.25), allergic rhinitis or conjunctivitis (OR = 1.15' CI 1.09-1.22), atopic dermatitis or eczema (OR = 1.08; CI, 1.04-1.13), food allergies (OR = 1.35; CI, 1.18-1.54), and allergic sensitization (OR = 1.19; CI, 1.10-1.28). Cesarean delivery did not significantly increase urticaria risk. Sensitivity analyses including only studies with a low risk of bias, adjusted estimates, prospective data collection, large sample sizes, or outcomes from medical records generally supported these findings. Offspring age, study region latitude, economy type, and cesarean delivery rate accounted for some of the clinical heterogeneity. We found no data on allergic purpura.

CONCLUSIONS

Most-adjusted estimates suggest that cesarean delivery is associated with increased risks of asthma, allergic rhinitis or conjunctivitis, atopic dermatitis or eczema, food allergies, and allergic sensitization in offspring. The impact of cesarean delivery on urticaria and purpura remains uncertain.

The association between caesarean section delivery and obesity at age 17 years. Evidence from a longitudinal cohort study in the United Kingdom

BACKGROUND

Childhood and adolescent obesity are major, preventable public health concerns. Studies to date are inconclusive regarding an association between caesarean section (CS) delivery and offspring obesity, with fewer studies conducted in late adolescence. This study examined the association between CS delivery, with a specific focus on planned CS, and induction of labour and adolescent body mass index (BMI) and body fat percentage (BF%) at age 17 years.

METHODS

Data on 8,880 mother-child pairs from the United Kingdom Millennium Cohort Study were analysed. The exposures were mode of delivery (normal vaginal delivery (VD) (reference), assisted VD, planned CS and emergency CS) and mode of delivery by induction of labour status. Crude and adjusted binary logistic regression and linear regression models were fitted examining BMI and BF% at age 17 years respectively, adjusting for several potential confounders.

RESULTS

Adolescents born by CS did not have an elevated BMI or BF% compared to those born by normal VD. The fully adjusted results for overweight and obesity in children born by planned CS, compared to VD, were 1.05 (95% CI: 0.86-1.28) and 0.94 (95% CI: 0.72-1.23), respectively. The results were similar for the associations between CS and BF%, and between induction of labour and BMI.

CONCLUSION

Overall, this large longitudinal study did not support an association between CS or induction of labour and overweight, obesity or BF%. It is possible that previously reported associations are due to residual or unmeasured confounding and/or underlying indications for CS delivery.

Crosstalk between Breast Milk N-Acetylneuraminic Acid and Infant Growth in a Gut Microbiota-Dependent Manner

The healthy growth of infants during early life is associated with lifelong consequences. Breastfeeding has positive impacts on reducing obesity risk, which is likely due to the varied components of breast milk, such as N-acetylneuraminic acid (Neu5Ac). However, the effect of breast milk Neu5Ac on infant growth has not been well studied. In this study, targeted metabolomic and metagenomic analyses were performed to illustrate the association between breast milk Neu5Ac and infant growth. Results demonstrated that Neu5Ac was significantly abundant in breast milk from infants with low obesity risk in two independent Chinese cohorts. Neu5Ac from breast milk altered infant gut microbiota and bile acid metabolism, resulting in a distinct fecal bile acid profile in the high-Neu5Ac group, which was characterized by reduced levels of primary bile acids and elevated levels of secondary bile acids. Taurodeoxycholic acid 3-sulfate and taurochenodeoxycholic acid 3-sulfate were correlated with high breast milk Neu5Ac and low obesity risk in infants, and their associations with healthy growth were reproduced in mice colonized with infant-derived microbiota. Parabacteroides might be linked to bile acid metabolism and act as a mediator between Neu5Ac and infant growth. These results showed the gut microbiota-dependent crosstalk between breast milk Neu5Ac and infant growth.

Maternal high-fat diet increases the susceptibility of offspring to colorectal cancer via the activation of intestinal inflammation

A high-fat diet plays a key role in the pathogenesis of colorectal cancer, and this effect on the gut can also occur in the offspring of mothers with a high-fat diet. In this review, we discuss the role of a high-fat diet in the pathogenesis of colorectal cancer and summarize the effects of a maternal high-fat diet on the activation of inflammation and development of colorectal cancer in offspring. Studies have found that a maternal high-fat diet primarily induces an inflammatory response in the colorectal tissue of both the mother herself and the offspring during pregnancy. This leads to the accumulation of inflammatory cells in the colorectal tissue and the release of inflammatory cytokines, which further activate the NF-κb and related inflammatory signaling pathways. Research suggests that high levels of lipids and inflammatory factors from mothers with a high-fat diet are passed to the offspring through the transplacental route, which induces colorectal inflammation, impairs the intestinal microecological structure and the intestinal barrier, and interferes with intestinal development in the offspring. This in turn activates the NF-κb and related signaling pathways, which further aggravates intestinal inflammation. This process of continuous inflammatory stimulation and repair may promote the uncontrolled proliferation of colorectal mucosal cells in the offspring, thus increasing their susceptibility to colorectal cancer.

Overweight and Obesity in Adult Birth by Cesarean Section: A Systematic Review With Meta-analysis

CONTEXT

Overweight/obesity is one of the most important health problems. Birth by cesarean section has been shown to influence long-term health outcomes including obesity.

OBJECTIVE

The aim of this systematic review-meta-analysis is to update acknowledgment of the increased risk of cesarean section on offspring's overweight/obesity.

METHODS

This study follows the PRISMA guidelines. A systematic literature search was conducted on Scopus, PubMed, and Web of Science; we have selected all the articles published until January 2, 2022. For inclusion, studies must have reported either (i) both birth by cesarean section and adult (≥18 years) offspring's body mass index; (ii) cohort or case-control study design; and (iii) a risk estimate. Heterogeneity testing was performed using Cochran's Q and I2 statistics. Publication bias was assessed by the Egger test and the Begg test. Meta-analysis was performed through a random-effects model.

RESULTS

Twelve studies with a combined population of 180 065 subjects were included in the meta-analysis. The overall analysis (N = 19) yielded a combined risk estimate for overweight/obesity of 1.19 (95% CI, 1.08-1.30) and the test of heterogeneity resulted into Q = 57.44 ( I2 = 68.67%, P ≤ .001). The risk of offspring obesity is 1.23 (95% CI, 1.09-1.39) and the test of heterogeneity resulted into Q = 39.55 ( I2 = 69.66%, P ≤ .001). Children born by cesarean section have an increased risk of obesity in adulthood.

The combined effect of pre-pregnancy body mass index and gestational weight gain on the risk of pre-labour and intrapartum caesarean section-The ICE-MCH study

Women who are obese before pregnancy have a higher risk of caesarean section than normal weight women. We investigated the combined effect of pre-pregnancy weight and gestational weight gain on pre-labour and intrapartum caesarean section risk. We collected data on 22,763 singleton, term, live deliveries in 2003-2014 from the Icelandic Maternal and Child Health Study (ICE-MCH), based on Icelandic registries. These were the Icelandic Medical Birth Registry and the Saga Maternal and Child Health Database. Pre-pregnancy body mass index was categorised into underweight, normal weight, overweight and obese. Gestational weight gain was classified according to the Institute of Medicine´s recommendation into below, within and above the recommended range. Logistic regression models, adjusted for maternal and gestational characteristics, were used to calculate adjusted odds ratios (AOR) and 95% confidence intervals (CI) for the risk of caesarean section. Obese women had a higher risk of pre-labour (AOR 1.56, 95% CI 1.34-1.81) and intrapartum caesarean section (AOR 1.92, 95% CI 1.70-2.17) than normal weight women in all categories of gestational weight gain. Gestational weight gain above the recommended range, compared to within the range, increased the risk of intrapartum caesarean section among normal weight (AOR 1.46, 95% CI 1.23-1.73) and overweight women (AOR 1.291, 95% CI 1.04-1.60). Gestational weight gain below the recommended range, compared to within the range, increased the risk of pre-labour caesarean section (AOR 1.64, 95% CI 1.20-2.25), but only among overweight women. Women who are obese before pregnancy have a high risk of caesarean section regardless of gestational weight gain. However, women who are normal weight or overweight before pregnancy and gain weight above the recommended range during pregnancy may also have an increased risk of caesarean section.

Risk Factors, Clinical Consequences, Prevention, and Treatment of Childhood Obesity

Obesity might adversely affect the health and well-being of children and their families. Childhood obesity has crucial implications for health, both during childhood and as they age. It is highly associated with many acute problems and is commonly present during childhood, making visits and hospital admissions polarized in this group of children. The problems that may affect these children can be medical, such as asthma, chronic inflammation, orthopedic abnormalities, liver disease, diabetes mellitus or dyslipidemia. Long-term consequences of cardiovascular risk factors, the persistence of obesity and premature mortality are common among adults who had obesity during their early lives. Additionally, they could also suffer from psychological issues, such as low self-esteem, which puts them at risk of a much more serious psychosocial problem that may lead to depression, as well as a disruption in educational achievements and social relationships. A healthy diet, physical activity, adequate sleep, and limited screen time are all preventive measures that should be implemented at the family and community levels, preferably through well-structured programs. Furthermore, pharmacological management of childhood obesity is limited and only used after non-pharmacological interventions have failed or in the late stages of obesity. However, recent guidelines advocate the early use of medical interventions. Approved pharmacotherapeutic options include orlistat, phentermine/topiramate combination and liraglutide. There are several other options approved primarily for other specific forms of obesity or for other indications, including setmelanotide, metformin, lisdexamfetamine, zonisamide and fluoxetine. Bariatric surgery is a safe and effective option in cases with extreme obesity and comorbidities considering the need for long-term monitoring and support for cases and their families post-surgery. This review aims to discuss and highlight the recent evidence regarding risk factors, clinical consequences, prevention, and treatment of childhood obesity.