Cesarean section and development of the immune system in the offspring

The influence of mode of delivery on neonatal and maternal short and long-term outcomes

OBJECTIVE

To evaluate the impact of mode of delivery on breastfeeding incentive practices and on neonatal and maternal short and long-term complications.

METHODS

A cohort study was conducted between June 2015 and April 2016 with 768 puerperal women from 11 maternities in Sergipe, interviewed in the first 24 hours, 45-60 days and 6-8 months after delivery. Associations between breastfeeding incentive practices, neonatal and maternal, both short-term and late complications, and the exposure variables were evaluated by the relative risk (95%CI) and the Fisher exact test.

RESULTS

The C-section newborns had less skin-to-skin contact immediately after delivery (intrapartum C-section: 0.18, 95%CI 0.1-0.31 and elective C-section: 0.36, 95%CI 0.27-0.47) and less breastfeeding within one hour of birth (intrapartum C-section: 0.43, 95%CI 0.29-0.63 and elective C-section: 0.44, 95%CI 0.33-0.59). Newborns from elective C-section were less frequently breastfed in the delivery room 0.42 (95%CI 0.2-0.88) and roomed-in less 0.85 (95%CI 0.77-0.95). Women submitted to intrapartum C-section had greater risk of early complications 1.3 (95%CI 1.04-1.64, p = 0.037) and sexual dysfunction 1.68 (95%CI 1.14-2.48, p = 0.027). The frequency of neonatal complications, urinary incontinence and depression according to the mode of delivery was similar.

CONCLUSIONS

The C-section was negatively associated with breastfeeding incentive practices; in addition, C-section after labor increased the risk of early maternal complications and sexual dysfunction.

Mode of delivery by an ulcerative colitis mother in a case of twins: Immunological differences in cord blood and placenta

AIM

To understand the effects of delivery mode on the immune cells frequency and function in cord blood and placenta.

METHODS

We evaluated immunological differences in cord blood and placental tissues for a case of twins one of which delivered vaginally while the other delivered by caesarian section (C-section). Cord blood mononuclear cells were isolated and placenta tissues were processed for cell isolation. Immune phenotyping was performed by flow cytometry methods following staining for T cells, natural killer (NK) cells, monocytes, neutrophils and CD71⁺ erythroid cells in both cord blood and placenta tissues. In addition, fetal calprotectin of twins was measured 12 wk after birth.

RESULTS

We found lower percentages of immune cells (e.g. T cells, monocytes and neutrophils) in the cord blood of C-section delivered compared to vaginally delivered newborn. In contrast, percentages of monocytes and neutrophils were > 2 folds higher in the placental tissues of C-section delivered newborn. More importantly, we observed lower percentages of CD71⁺ erythroid cells in both cord blood and placental tissues of C-section delivered case. Lower CD71⁺ erythroid cells were associated with a more pro-inflammatory milieu at the fetomaternal interface reflected by higher expression of inhibitory receptors on CD4⁺ T cells, higher frequency of monocytes and neutrophils. Furthermore, type of delivery impacted the gene expression profile in CD71⁺ erythroid cells. Finally, we found that C-section delivered child had > 20-fold higher FCP in his fecal sample at 12 wk of age.

CONCLUSION

Mode of delivery impacted immune cells profile in cord blood/placenta. In particular frequency of immunosuppressive CD71⁺ erythroid cells was reduced in C-section delivered newborn.

Trimester-specific association between antibiotics exposure during pregnancy and childhood asthma or wheeze: the role of confounding

PURPOSE

We conducted the meta-analysis to respectively evaluate the risk of prenatal antibiotics use during specific trimesters (first, second, and third trimester) on childhood asthma or wheeze and to explore whether the association was biased by potential confounding.

METHODS

The quality of included articles was assessed according to Newcastle-Ottawa Quality Assessment Scale and the Strengthening the Reporting of Observational Studies in Epidemiology. A random effects model was used to calculate pooled risk ratios and corresponding 95% confidence interval (CI), and publication bias was tested by Egger statistical test.

RESULTS

Eight studies were included finally. We found a crude positive association of prenatal antibiotics use during each pregnancy trimester and risk of childhood asthma or wheeze with RRs of 1.28 (95% CI, 1.09-1.51) for the first trimester of pregnancy, 1.25 (95% CI, 1.02-1.52) for the second trimester, and 1.25 (95% CI, 1.05-1.49) for the third trimester. However, when considering potential factors of maternal infections and presence of siblings, the relationship for each trimester was insignificant.

CONCLUSIONS

This systemic review and meta-analysis proposed a crude positive association between prenatal antibiotic use in every specific trimester and risk of childhood asthma or wheeze. However, adjustment for confounders decreased the relative risk estimates, supporting the concept that these associations are, at least in part, because of confounding by indication.

Birth delivery mode alters perinatal cell death in the mouse brain

Labor and a vaginal delivery trigger changes in peripheral organs that prepare the mammalian fetus to survive ex utero. Surprisingly little attention has been given to whether birth also influences the brain, and to how alterations in birth mode affect neonatal brain development. These are important questions, given the high rates of cesarean section (C-section) delivery worldwide, many of which are elective. We examined the effect of birth mode on neuronal cell death, a widespread developmental process that occurs primarily during the first postnatal week in mice. Timed-pregnant dams were randomly assigned to C-section deliveries that were yoked to vaginal births to carefully match gestation length and circadian time of parturition. Compared with rates of cell death just before birth, vaginally-born offspring had an abrupt, transient decrease in cell death in many brain regions, suggesting that a vaginal delivery is neuroprotective. In contrast, cell death was either unchanged or increased in C-section-born mice. Effects of delivery mode on cell death were greatest for the paraventricular nucleus of the hypothalamus (PVN), which is central to the stress response and brain-immune interactions. The greater cell death in the PVN of C-section-delivered newborns was associated with a reduction in the number of PVN neurons expressing vasopressin at weaning. C-section-delivered mice also showed altered vocalizations in a maternal separation test and greater body mass at weaning. Our results suggest that vaginal birth acutely impacts brain development, and that alterations in birth mode may have lasting consequences.

Congenital Nasolacrimal Duct Obstruction and Its Association With the Mode of Birth

PURPOSE

To assess the association of congenital nasolacrimal duct obstruction (CNLDO) with mode of birth (vaginal or cesarean).

METHODS

This study was a prospective interventional case series of 200 consecutive cases of CNLDO presenting at a tertiary care center. Data collected include demographics, mode of delivery, elective or emergency cesarean section, primary or secondary cesarean sections, type of CNLDO (simple or complex), management, and outcomes. Statistical significance was set at a P value of less than .05.

RESULTS

Of the 200 consecutive patients, 97 (48.5%) were vaginal deliveries and 103 (51.5%) were cesarean sections. Of the 103 cesarean section patients, 57 (55.3%) were primary cesarean sections and the remaining were secondary cesarean sections. Based on the type of CNLDO, 172 (86%) were simple CNLDO. In general, the current study did not find any significant association between the incidence of CNLDO and mode of delivery. Among the complex CNLDO cohort (n = 28), a significant association was found with cesarean section delivery (P = .016); however, no such association was noted when the patients were analyzed with regard to their age at presentation.

CONCLUSIONS

The current study did not find an overall significant association between CNLDO and the mode of delivery; however, the subset of patients with complex CNLDO showed a significant association with cesarean section. [J Pediatr Ophthalmol Strabismus. 2018;55(4):266-268.].

Cesarean Delivery and Childhood Malignancies: A Single-Center, Population-Based Cohort Study

Rising rates of cesarean deliveries worldwide prompt the evaluation of long-term morbidity to the offspring. In this retrospective cohort study, we evaluated whether cesarean delivery influences the development of childhood malignancies. We identified an association of cesarean delivery with acute lymphoblastic leukemia in children, suggesting prudence in the recommendation of cesarean delivery for nonmedically indicated cases.

Early fecal microbiota composition in children who later develop celiac disease and associated autoimmunity

OBJECTIVES

Several studies have reported that the intestinal microbiota composition of celiac disease (CD) patients differs from healthy individuals. The possible role of gut microbiota in the pathogenesis of the disease is, however, not known. Here, we aimed to assess the possible differences in early fecal microbiota composition between children that later developed CD and healthy controls matched for age, sex and HLA risk genotype.

MATERIALS AND METHODS

We used 16S rRNA gene sequencing to examine the fecal microbiota of 27 children with high genetic risk of developing CD. Nine of these children developed the disease by the age of 4 years. Stool samples were collected at the age of 9 and 12 months, before any of the children had developed CD. The fecal microbiota composition of children who later developed the disease was compared with the microbiota of the children who did not have CD or associated autoantibodies at the age of 4 years. Delivery mode, early nutrition, and use of antibiotics were taken into account in the analyses.

RESULTS

No statistically significant differences in the fecal microbiota composition were found between children who later developed CD (n = 9) and the control children without disease or associated autoantibodies (n = 18).

CONCLUSIONS

Based on our results, the fecal microbiota composition at the age of 9 and 12 months is not associated with the development of CD. Our results, however, do not exclude the possibility of duodenal microbiota changes or a later microbiota-related trigger for the disease.

Asthma and atopic dermatitis after early-, late-, and post-term birth

OBJECTIVE

To assess the incidence and risk factors of asthma and atopic dermatitis by seven years of age after early-term (ET) (37⁺⁰ -38⁺⁶ weeks), full-term (FT) (39⁺⁰ -40⁺⁶ weeks), late-term (LT) (41⁺⁰ -41⁺⁶ weeks), and especially post-term (PT) (≥42 weeks) birth.

METHODS

Altogether, 965 203 infants born between 1991 and 2008 in Finland were investigated in ET, FT, LT, and PT groups. Data on asthma medication reimbursement and hospital visits for atopic dermatitis were retrieved from national health databases.

RESULTS

The frequencies of asthma medication reimbursement in the ET, FT, LT, and PT groups were 4.5%, 3.7%, 3.3%, and 3.2%, respectively. Hospital visits due to atopic dermatitis were most common after PT birth. Compared with FT births, ET births were associated with an increased risk of asthma (adjusted odds ratio (aOR), 95% confidence interval (CI) 1.20, 1.17-1.23), while LT (aOR, 95%CI 0.91, 0.89-0.93) births and PT (aOR, 95%CI 0.87, 0.83-0.92) births decreased this risk. PT birth (aOR, 95%CI 1.06, 1.01-1.10) predicted atopic dermatitis. From a population point of view, the most relevant risk factors for asthma were male sex, ET birth, smoking during pregnancy and birth by elective cesarean section, and for atopic dermatitis male sex, first delivery, birth in a level II hospital and birth by cesarean section.

CONCLUSIONS

Early-term birth was a predictor of asthma, and PT birth was associated with atopic dermatitis. Counseling against smoking and following strict indications for planned ET deliveries and cesarean sections may be means to reduce the risk of later asthma.

Cesarean Delivery and Risk of Infant Leukemia: A Report from the Children's Oncology Group

Background: Studies have reported increased risks of pediatric acute lymphoblastic leukemia (ALL) among children born by cesarean delivery (CD). However, no previous study has examined the impact of CD on risk of infant leukemia specifically.Methods: In this study, 443 infants diagnosed with acute leukemia, including both ALL and acute myelogenous leukemia (AML), were identified at Children's Oncology Group institutions between January 1996 and December 2006; 324 controls frequency matched by year of birth were identified though random digit dialing and random selection from U.S. birth registries. Using interview data and, for a subset of participants, medical record data, we analyzed CD overall and by indications that likely resulted in pre-labor CD (PLCD) or emergency CD (ECD). Odds ratios (ORs) and 95% confidence intervals (CIs) for risk of ALL and AML were estimated using multivariable unconditional logistic regression models, adjusted for year of birth, birth weight, and maternal race.Results: We observed an increased point estimate for the association between CD and ALL (OR, 1.52 and 95% CI, 1.02-2.25). We did not observe an association between CD and AML (OR, 1.02 and 95% CI, 0.64-1.62). In analyses of indication for CD, we observed elevated effect estimates for the associations of both PLCD and ECD and infant ALL.Conclusions: Our analysis suggests an increased risk of infant ALL following CD, including both PLCD and ECD. Altered microbiota colonization may be involved in development of leukemia in infants, but clear biological mechanisms have yet to be determined.Impact: This study provides the first in-depth examination of CD and infant leukemia. Cancer Epidemiol Biomarkers Prev; 27(4); 473-8. ©2018 AACR.

The Neonatal Microbiome and Its Partial Role in Mediating the Association between Birth by Cesarean Section and Adverse Pediatric Outcomes

BACKGROUND

Cesarean sections (CS) are among the most commonly performed surgical procedures in the world. Epidemiologic data has associated delivery by CS with an increased risk of certain adverse health outcomes in children, such as asthma and obesity.

OBJECTIVE

To explore what is known about the effect of mode of delivery on the development of the infant microbiome and discuss the potentially mediating role of CS-related microbial dysbiosis in the development of adverse pediatric health outcomes. Recommendations for future inquiry are also provided.

METHODS

This study provides a narrative overview of the literature synthesizing the findings of literature retrieved from searches of PubMed and other computerized databases and authoritative texts.

RESULTS

Emerging evidence suggests that mode of delivery is involved in the development of the neonatal microbiome and may partially explain pediatric health outcomes associated with birth by CS. Specifically, the gut microbiome of vaginally delivered infants more closely resembles their mothers' vaginal microbiome and thus more commonly consists of potentially beneficial microbiota such as Lactobacillus, Bifidobacterium, and Bacteroides. Conversely, the microbiome of infants born via CS shows an increased prevalence of either skin flora or potentially pathogenic microbial communities such as Klebsiella, Enterococcus, and Clostridium.

CONCLUSIONS

Mode of delivery plays an important role in the development of the postnatal microbiome but likely tells only part of the story. More comprehensive investigations into all the pre- and perinatal factors that have the potential to contribute to the neonatal microbiome are warranted.

Association between Cesarean Section and Weight Status in Chinese Children and Adolescents: A National Survey

Previous research on the association between cesarean section (CS) and childhood obesity has yielded inconsistent findings. This study assessed the secular trend of CS and explored the relationship between CS and the risks of overweight and obesity in Chinese children and adolescents. Data came from a national multicenter school-based study conducted in seven provinces of China in 2013. Covariate data including weight, height and delivery mode were extracted. Poisson regression was applied to determine the risk ratios (RRs) and 95% confidence intervals (CIs) for the risks of overweight and obesity associated with the delivery mode. A total of 18,780 (41.2%) subjects were born by CS between 1997 and 2006. The rate of CS increased from 27.2% in 1997 to 54.1% in 2006. After adjusting for major confounders, the RRs (95% CI) of overweight and obesity among subjects born by CS were 1.21 (1.15 to 1.27) and 1.51 (1.42 to 1.61), respectively. Similar results were observed in different subgroups stratified by sex, age, and region. In summary, the CS rate increased sharply in China between 1997 and 2006. CS was associated with increased risks of overweight and obesity in offspring after accounting for major confounding factors.

Birth delivery method affects expression of immune genes in lung and jejunum tissue of neonatal beef calves

Background

Caesarean section is a routine veterinary obstetrical procedure employed to alleviate dystocia in cattle. However, CS, particularly before the onset of labour, is known to negatively affect neonatal respiration and metabolic adaptation in humans, though there is little published information for cattle. The aim of this study was to investigate the effect of elective caesarean section (ECS) or normal trans-vaginal (TV) delivery, on lung and jejunal gene expression profiles of neonatal calves.

Results

Paternal half-sib Angus calves (gestation length 278 + 1.8 d) were delivered either transvaginally (TV; n = 8) or by elective caesarean section (ECS; n = 9) and immediately euthanized. Lung and jejunum epithelial tissue was isolated and snap frozen. Total RNA was extracted using Trizol reagent and reverse transcribed to generate cDNA. For lung tissue, primers were designed to target genes involved in immunity, surfactant production, cellular detoxification, membrane transport and mucin production. Primers for jejunum tissue were chosen to target mucin production, immunoglobulin uptake, cortisol reaction and membrane trafficking. Quantitative real-time PCR reactions were performed and data were statistically analysed using mixed models ANOVA. In lung tissue the expression of five genes were affected (p < 0.05) by delivery method. Four of these genes were present at lower (LAP, CYP1A1, SCN11α and SCN11β) and one (MUC5AC) at higher abundance in ECS compared with TV calves. In jejunal tissue, expression of TNFα, Il-1β and 1 l-6 was higher in ECS compared with TV calves.

Conclusions

This novel study shows that ECS delivery affects the expression of key genes involved in the efficiency of the pulmonary liquid to air transition at birth, and may lead to an increased inflammatory response in jejunal tissue, which could compromise colostral immunoglobulin absorption. These findings are important to our understanding of the viability and management of neonatal calves born through ECS.

Dental Caries and Developmental Defects of Enamel in the Primary Dentition of Preterm Infants: Case-Control Observational Study

AIM

Assessment of dental health in the primary dentition of preterm infants (PTI) including investigation of mother- and infant-related risk factors in a case-control study design.

MATERIAL AND METHODS

One hundred twenty-eight infants aged 3-4 years were included. Sixty-four PTI (27 males) were randomly selected from the preterm registry of the Jena University Hospital. As a control group served 64 full-term infants (FTI) recruited from the Department of Paediatric Dentistry, matched for age and sex. Dental examinations were provided by one dentist under standard clinical conditions. Caries was scored using the International Caries Detection and Assessment System (ICDAS II) and the DMFT, gingival health using the Periodontal Screening Index, and developmental defects of enamel using the DDE index. Mother- and infant-related factors were collected via a questionnaire and from medical records.

RESULTS

The caries prevalence was 50.0% (ICDAS II >0) in PTI and 12.5% (ICDAS II >0) in FTI. The caries experience was higher in PTI (DMFT 1.0 ± 3.1) than in FTI (DMFT 0.3 ± 1.0). PTI had a higher risk of caries (OR 7.0), initial lesions (OR 6.2), DDE (OR 7.5), and gingivitis (OR 6.5) than FTI. The highest risk occurred in PTI with an extremely low birth weight (<1,000 g). A higher risk of DDE was present when mothers suffered from illness during pregnancy (OR 3.9). A higher risk of caries was revealed in infants with respiratory syndrome (OR 6.2) or when their mothers had a lower socioeconomic status (OR 6.3).

CONCLUSIONS

PTI had less healthy teeth than FTI and are at a higher risk for DDE, caries, and gingivitis. The poorer dental health in PTI is associated with a low birth weight, a low socioeconomic status, and mothers' illness during pregnancy.

Hygiene Hypothesis in Asthma Development: Is Hygiene to Blame?

Industrialized countries have registered epidemic rates on allergic diseases, such as hay fever, asthma, eczema, and food allergies. The Hygiene Hypothesis was born from work made by Dr. David Strachan, who observed that younger siblings were less susceptible to eczema and asthma, and proposed that this was a result of increased transmission of infectious agents via unhygienic practices within a household. This initial hypothesis was then reframed as the old friends/microbiota hypothesis, implicating non-pathogenic commensal microorganisms as the source of immunomodulatory signals necessary to prevent immune-mediated chronic disorders. Although the hygiene hypothesis is supported by epidemiological research of allergic diseases in certain industrialized settings, it often fails to explain the incidence of asthma in less affluent regions of the world. In this review, we summarize up-to-date information on genetic and environmental factors associated with asthma in different human populations, and present evidence that calls for caution when associating hygiene with the pathogenesis of asthma and other allergic conditions.

The mother-offspring dyad: microbial transmission, immune interactions and allergy development

The increasing prevalence of allergy in affluent countries may be caused by reduced intensity and diversity of microbial stimulation, resulting in abnormal postnatal immune maturation. Most studies investigating the underlying immunomodulatory mechanisms have focused on postnatal microbial exposure, for example demonstrating that the gut microbiota differs in composition and diversity during the first months of life in children who later do or do not develop allergic disease. However, it is also becoming increasingly evident that the maternal microbial environment during pregnancy is important in childhood immune programming, and the first microbial encounters may occur already in utero. During pregnancy, there is a close immunological interaction between the mother and her offspring, which provides important opportunities for the maternal microbial environment to influence the immune development of the child. In support of this theory, combined pre- and postnatal supplementations seem to be crucial for the preventive effect of probiotics on infant eczema. Here, the influence of microbial and immune interactions within the mother-offspring dyad on childhood allergy development will be discussed. In addition, how perinatal transmission of microbes and immunomodulatory factors from mother to offspring may shape appropriate immune maturation during infancy and beyond, potentially via epigenetic mechanisms, will be examined. Deeper understanding of these interactions between the maternal and offspring microbiome and immunity is needed to identify efficacious preventive measures to combat the allergy epidemic.

Mode of delivery and child and adolescent psychological well-being: Evidence from Hong Kong's "Children of 1997" birth cohort

Mode of delivery (vaginal or cesarean section) is thought to affect gut microbiota, which in turn may affect psychological well-being. As such, mode of delivery is potentially a modifiable factor for psychological well-being. Here we examined the association of mode of delivery with child and adolescent psychological well-being. We used multivariable linear regression in a population-representative Hong Kong Chinese birth cohort, “Children of 1997,” to examine the adjusted associations of mode of delivery with behavioral problems assessed from parent-reported Rutter score at ~7 (n = 6294) and ~11 years (n = 5598), self-esteem assessed from self-reported Culture-Free Self-Esteem Inventory score at ~11 years (n = 6937) and depressive symptoms assessed from self-reported Patient Health Questionnaire-9 score at ~13 years (n = 5797). Cesarean Section (CS) was associated with children born in private hospitals, boys, and firstborns, higher maternal body mass index, higher maternal age, preeclampsia, higher socioeconomic position (SEP) and maternal birth in Hong Kong. CS was unrelated to behavior, self-esteem and depressive symptoms adjusted for infant characteristics (sex, gestational age, birthweight, parity and breast feeding), maternal characteristics (mother’s age and place of birth) and SEP. In a developed non-Western setting, mode of delivery was not clearly associated with childhood or early adolescent psychological well-being.

A Perspective on Brain-Gut Communication: The American Gastroenterology Association and American Psychosomatic Society Joint Symposium on Brain-Gut Interactions and the Intestinal Microenvironment

BACKGROUND

Alterations in brain-gut communication and the intestinal microenvironment have been implicated in a variety of medical and neuropsychiatric diseases. Three central areas require basic and clinical research: (1) how the intestinal microenvironment interacts with the host immune system, central nervous system, and enteric nervous system; (2) the role of the intestinal microenvironment in the pathogenesis of medical and neuropsychiatric disease; and (3) the effects of diet, prebiotics, probiotics, and fecal microbiota transplantation on the intestinal microenvironment and the treatment of disease.

METHODS

This review article is based on a symposium convened by the American Gastroenterology Association and the American Psychosomatic Society to foster interest in the role of the intestinal microenvironment in brain-gut communication and pathogenesis of neuropsychiatric and biopsychosocial disorders. The aims were to define the state of the art of the current scientific knowledge base and to identify guidelines and future directions for new research in this area.

RESULTS

This review provides a characterization of the intestinal microbial composition and function. We also provide evidence for the interactions between the intestinal microbiome, the host, and the environment. The role of the intestinal microbiome in medical and neuropsychiatric diseases is reviewed as well as the treatment effects of manipulation of the intestinal microbiome.

CONCLUSIONS

Based on this review, opportunities and challenges for conducting research in the field are described, leading to potential avenues for future research.

Associations of caesarean delivery and the occurrence of neurodevelopmental disorders, asthma or obesity in childhood based on Taiwan birth cohort study

OBJECTIVES

Whether birth by caesarean section (CS) increases the occurrence of neurodevelopmental disorders, asthma or obesity in childhood is controversial. We tried to demonstrate the association between children born by CS and the occurrence of the above three diseases at the age of 5.5 years.

METHODS

The database of the Taiwan Birth Cohort Study which was designed to assess the developmental trajectories of 24 200 children born in 2005 was used in this study. Associations between children born by CS and these three diseases were evaluated before and after controlling for gestational age (GA) at birth, children's characteristics and disease-related predisposing factors.

RESULTS

Children born by CS had significant increases in neurodevelopmental disorders (20%), asthma (14%) and obesity (18%) compared with children born by vaginal delivery. The association between neurodevelopmental disorders and CS was attenuated after controlling for GA at birth (OR 1.15; 95% CI 0.98 to 1.34). Occurrence of neurodevelopmental disorders steadily declined with increasing GA up to ≤40-42 weeks. CS and childhood asthma were not significantly associated after controlling for parental history of asthma and GA at birth. Obesity in childhood remained significantly associated with CS (OR 1.13; 95% CI 1.04 to 1.24) after controlling for GA and disease-related factors.

CONCLUSIONS

Our results implied that the association between CS birth and children's neurodevelopmental disorders was significantly influenced by GA. CS birth was weakly associated with childhood asthma since parental asthma and preterm births are stronger predisposing factors. The association between CS birth and childhood obesity was robust after controlling for disease-related factors.

Surge of immune cell formation at birth differs by mode of delivery and infant characteristics-A population-based cohort study

BACKGROUND

Birth by cesarean section is associated with increased risks of immune disorders. We tested whether establishment of immune function at birth relates to mode of delivery, taking other maternal and infant characteristics into account.

METHODS AND FINDINGS

Using a prospectively collected database, we retrieved information on maternal and infant characteristics of 6,014 singleton infants delivered from February to April 2014 in Stockholm, Sweden, with gestational age ≥35 weeks, Apgar scores ≥7, and without congenital malformations or any neonatal morbidity. We linked our data to blood levels of T-cell receptor excision circles (TREC) and κ-deleting recombination excision circles (KREC), determined as part of a neonatal screening program for immune-deficiencies, and representing quantities of newly formed T- and B-lymphocytes. Multivariate logistic regression was used to calculate odds ratios (OR) with 95% confidence intervals (CI) for participants having TREC and KREC levels in the lowest quintile. Multivariate models were adjusted for postnatal age at blood sampling, and included perinatal (mode of delivery, infant sex, gestational age, and birth weight for gestational age), and maternal characteristics (age, parity, BMI, smoking, diabetes, and hypertensive disease). Low TREC was associated with cesarean section before labor (adjusted OR:1.32 [95% CI 1.08-1.62]), male infant sex (aOR:1.60 [1.41-1.83]), preterm birth at 35-36 weeks of gestation (aOR:1.89 [1.21-2.96]) and small for gestational age (aOR:1.67 [1.00-2.79]). Low KREC was associated with male sex (aOR:1.32 [1.15-1.50]), postterm birth at ≥42 weeks (aOR:1.43 [1.13-1.82]) and small for gestational age (aOR:2.89 [1.78-4.69]). Maternal characteristics showed no consistent associations with neonatal levels of either TREC or KREC.

CONCLUSION

Cesarean section before labor was associated with lower T-lymphocyte formation, irrespective of maternal characteristics, pregnancy, and neonatal risk factors. The significance of a reduced birth-related surge in lymphocyte formation for future immune function and health remains to be investigated.

Do bacteria shape our development? Crosstalk between intestinal microbiota and HPA axis

The human body contains as many bacteria in the intestine as the total number of human body cells. These bacteria have a central position in human health and disease, and would also play a role in the regulation of emotions, behavior, and even higher cognitive functions. The Hypothalamic-Pituitary-Adrenal axis (HPA axis) is a major physiological stress system that produces cortisol. This hormone is involved in responding to environmental stress and also shapes many aspects of brain development. Both the HPA axis and the intestinal microbiota show rapid and profound developmental changes during the first years of life. Early environmental disturbances can affect the development of both systems. Early adversity, for example, is known to lead to later unbalances in both, as well as to psychopathological behavior and emotions. The goal of this theoretical review is to summarize current knowledge on the developmental crosstalk between the intestinal microbiota and the HPA axis, providing a basis for understanding the development and bidirectional communication between these two essential systems in human functioning.

The relation between cesarean birth and child cognitive development

This is the first detailed study of the relation between cesarean birth and child cognitive development. We measure differences in child cognitive performance at 4 to 9 years of age between cesarean-born and vaginally-born children (n = 3,666) participating in the Longitudinal Study of Australian Children (LSAC). LSAC is a nationally representative birth cohort surveyed biennially. Using multivariate regression, we control for a large range of confounders related to perinatal risk factors and the socio-economic advantage associated with cesarean-born children. Across several measures, we find that cesarean-born children perform significantly below vaginally-born children, by up to a tenth of a standard deviation in national numeracy test scores at age 8–9. Estimates from a low-risk sub-sample and lower-bound analysis suggest that the relation is not spuriously related to unobserved confounding. Lower rates of breastfeeding and adverse child and maternal health outcomes that are associated with cesarean birth are found to explain less than a third of the cognitive gap, which points to the importance of other mechanisms such as disturbed gut microbiota. The findings underline the need for a precautionary approach in responding to requests for a planned cesarean when there are no apparent elevated risks from vaginal birth.

Caesarean Section is associated with reduced perinatal cytokine response, increased risk of bacterial colonization in the airway, and infantile wheezing

The relationship between cesarean section (CS) and allergic disorders such as asthma and wheezing has been inconsistent, and the mechanisms for their connection remained largely unknown. We aimed to investigate whether CS is associated with infantile wheeze and to explore the connection between CS and several risk factors known to correlate with allergy development. Mononuclear cells were isolated from cord blood and assessed for cytokine responses by ELISA. Bacteria from nasopharyngeal specimens were identified with traditional culture methods. Infant lung function tests were performed at 6 and 12 months of age. IgE levels and clinical outcomes were assessed at 12 months. The result showed that children delivered by CS were associated with increased risk of wheezing (aHR 1.63; 95% CI: 1.01–2.62) and decreased compliance of the respiratory system at 12 months (p = 0.045). In addition, CS was associated with reduced TLR1–2- triggered TNF-α and IL-6 responses at birth. By12 months of age, children delivered by CS had significantly less airway bacterial clearance. Our findings suggested that CS was associated with decreased pro-inflammatory cytokine response to TLR1–2 stimulation, followed by higher abundance of bacterial colonization in the airway during late infancy, thus increasing the risk of infantile wheezing.

Clinical chorioamnionitis at term VIII: a rapid MMP-8 test for the identification of intra-amniotic inflammation

OBJECTIVE

Clinical chorioamnionitis is the most common infection/inflammatory process diagnosed in labor and delivery units worldwide. The condition is a syndrome that can be caused by (1) intra-amniotic infection, (2) intra-amniotic inflammation without demonstrable microorganisms (i.e. sterile intra-amniotic inflammation), and (3) maternal systemic inflammation that is not associated with intra-amniotic inflammation. The presence of intra-amniotic inflammation is a risk factor for adverse maternal and neonatal outcomes in a broad range of obstetrical syndromes that includes clinical chorioamnionitis at term. Although the diagnosis of intra-amniotic infection has relied on culture results, such information is not immediately available for patient management. Therefore, the diagnosis of intra-amniotic inflammation could be helpful as a proxy for intra-amniotic infection, while results of microbiologic studies are pending. A rapid test is now available for the diagnosis of intra-amniotic inflammation, based on the determination of neutrophil collagenase or matrix metalloproteinase-8 (MMP-8). The objectives of this study were (1) to evaluate the diagnostic indices of a rapid MMP-8 test for the identification of intra-amniotic inflammation/infection in patients with the diagnosis of clinical chorioamnionitis at term, and (2) to compare the diagnostic performance of a rapid MMP-8 test to that of a conventional enzyme-linked immunosorbent assay (ELISA) interleukin (IL)-6 test for patients with clinical chorioamnionitis at term.

MATERIALS AND METHODS

A retrospective cohort study was conducted. A transabdominal amniocentesis was performed in patients with clinical chorioamnionitis at term (n=44). Amniotic fluid was analyzed using cultivation techniques (for aerobic and anaerobic bacteria as well as genital Mycoplasmas) and broad-range polymerase chain reaction (PCR) coupled with electrospray ionization mass spectrometry (PCR/ESI-MS). Amniotic fluid IL-6 concentrations were determined by ELISA, and rapid MMP-8 results were determined by Yoon's MMP-8 Check®. Intra-amniotic inflammation was defined as an elevated amniotic fluid IL-6 concentration ≥2.6 ng/mL, and intra-amniotic infection was diagnosed by the presence of microorganisms in the amniotic fluid accompanied by intra-amniotic inflammation. The diagnostic indices of Yoon's MMP-8 Check® for the identification of intra-amniotic inflammation were calculated. In order to objectively compare Yoon's MMP-8 Check® with the ELISA IL-6 test for the identification of intra-amniotic inflammation, we used an amniotic fluid white blood cell (WBC) count ≥50 cells/mm3 to define intra-amniotic inflammation.

RESULTS

(1) A positive rapid MMP-8 test had a sensitivity of 82.4% (28/34), specificity of 90% (9/10), positive predictive value of 96.6% (28/29), negative predictive value of 60% (9/15), positive likelihood ratio 8.2 (95% CI 1.3-53.2), and negative likelihood ratio 0.2 (95% CI 0.1-0.4) for the identification of intra-amniotic inflammation (prevalence 77.3%); (2) a positive rapid MMP-8 test had a sensitivity of 91.7% (22/24), specificity of 65% (13/20), positive predictive value of 75.9% (22/29), negative predictive value of 86.7% (13/15), positive likelihood ratio of 2.6 (95% CI 1.4-4.8), and negative likelihood ratio of 0.1 (95% CI 0.03-0.5) for the identification of intra-amniotic infection; (3) the rapid MMP-8 test had a significantly higher specificity than the ELISA IL-6 test in the identification of intra-amniotic inflammation as determined by an amniotic fluid WBC count ≥50 cells/mm3. The sensitivity and accuracy of the rapid MMP-8 test were comparable to those of the ELISA IL-6 test; and (4) importantly, the rapid MMP-8 test had 100% sensitivity and 100% negative predictive value in the identification of neonates affected with fetal inflammatory response syndrome (FIRS).

CONCLUSION

The rapid diagnosis of intra-amniotic inflammation is possible by analysis of amniotic fluid using a point-of-care test for MMP-8. Patients with a positive test are at risk of delivering a neonate affected with systemic inflammation, a risk factor for adverse neonatal outcome.

Cesarean Delivery and Body Mass Index at 6 Months and Into Childhood

BACKGROUND AND OBJECTIVES

The prevalence of cesarean delivery (CD) is rising worldwide, and so is childhood obesity. Studies have shown associations between these factors. We examined the development of BMI from birth through childhood to determine whether CDs were associated with differences in growth and obesity.

METHODS

Term children from the birth cohorts Copenhagen Prospective Studies on Asthma in Childhood₂₀₀₀ (COPSAC₂₀₀₀) and COPSAC₂₀₁₀ were included. Height, length, and weight measurements were collected prospectively until 5 years in COPSAC₂₀₁₀ and until 13 years in COPSAC₂₀₀₀. Dual-energy x-ray absorptiometry (DXA) scans were performed at 3.5 and 7 years. Information on relevant covariates were verified during clinical visits. Analyses were adjusted for covariates associating with CD.

RESULTS

In COPSAC₂₀₁₀, 20% (N = 138/673) of the children were delivered by CD; 49% were girls. In COPSAC₂₀₀₀, 19% (N = 76/393) were delivered by CD; 51% were girls. Children delivered by CD had a higher mean BMI at 6 months compared with those delivered vaginally: COPSAC₂₀₁₀ β-coefficient, .41 (95% confidence interval [CI], .12 to .69), P = .01; COPSAC₂₀₀₀ β-coefficient, .16 (95% CI, -.11 to .68), P = .16; and meta-analysis β-coefficient, .37 (95% CI, .14 to .60), P = .002. There were no differences in BMI trajectory between the 2 groups by 5 and 13 years, nor cross-sectional BMI at 5 and 13 years, nor in fat percentages from DXA scans.

CONCLUSIONS

Children delivered by CD had a higher BMI at 6 months of age, but this difference did not track into later childhood. Our study does not support the hypothesis that CD leads to later overweight.

From therapeutic to elective cesarean deliveries: factors associated with the increase in cesarean deliveries in Chiapas

BACKGROUND

Cesarean deliveries have increased over the past decade in Mexico, including those states with high percentages of indigenous language speakers, e.g., Chiapas. However, the factors contributing to this trend and whether they affect indigenous languages populations remain unknown. Thus, this work aims to identify some of the factors controlling the prevalence of cesarean sections (C-sections) in Chiapas between the 2011-2014 period.

METHODS

We analyzed certified birth data, compiled by the Subsystem of Information on Births of the Secretary of Health and the National Institute of Statistics and Geography, and information regarding the Human Development Index (HDI), assembled by the United Nations Development Program. A descriptive analysis of the variables and a multilevel logistics regression model were employed to assess the role of the different factors in the observed trends.

RESULTS

The results show that the factors contributing to the increased risk of C-sections are (i) women residing in municipalities with indigenous population and municipalities with high HDIs, (ii) advanced schooling, (iii) frequent prenatal checkups, and (iv) deliveries occurring in private health clinics. Furthermore, C-sections might also be associated with prolonged hospital stays.

CONCLUSIONS

The increasing frequency of C-sections among indigenous populations in Chiapas seems to be related to public policies aimed at reducing maternal mortality in Mexico. Therefore, public health policy needs to be revisited to ensure that reproductive rights are being respected.

Birth by caesarean section and school performance in Swedish adolescents- a population-based study

Background

Our objective was to assess the impact of obstetric mode of delivery, and in particular birth by Caesarean section (CS), on school performance in adolescents using a large, population-based cohort.

Methods

We extracted data from the Swedish Medical Birth Register and National School Register. We included all live singleton births in Sweden from 1982–1995 (n = 1,489,925). School grades were reported on a scale from 0 to 320, scores less than 160 (i.e. “pass”) were considered to be “poor school performance.” Mode of delivery was categorised as: unassisted vaginal delivery (VD), assisted VD, elective CS and emergency CS. We measured the association between mode of delivery and “poor school performance” using logistic regression. We then used quantile regression to assess the association between mode of delivery and school performance across the distribution of scores. We adjusted for maternal age, parity, small and large for gestational age, gestational age, maternal country of birth, maternal depression, non-affective disorder or bipolar disorder, parental income at time of birth, and parental social welfare at time of birth. We also conducted sensitivity analyses to investigate the association further.

Results

With logistic regression analysis, the adjusted odds ratio (aOR) of assisted VD and poor school performance, compared to unassisted VD, was 1.06 (95% CI: 1.03–1.08). For elective CS it was 1.06 (95% CI:1.03-1.09) and for emergency CS it was 1.12 (95% CI: 1.09–1.15). With quantile regression, assisted VD showed little difference in scores, when compared to unassisted VD, at any point across the distribution. Elective CS was associated with a 1–3 point decrease in scores, and emergency CS was associated with a 2–5 point decrease in scores.

Conclusion

A slight association was found between birth by CS and school performance. However, the effect was quite small and given the complex nature of the relationship, should be interpreted with caution.

Electronic supplementary material

The online version of this article (doi:10.1186/s12884-017-1304-x) contains supplementary material, which is available to authorized users.

Manipulating the baby biome: What are the issues?

Establishing a baby biome through the controversial practice of 'vaginal seeding' has generated interest among the general public and healthcare providers alike. We discuss the potential risks of this practice and offer a harm minimisation approach to managing women requesting vaginal microbiome transfer after delivery by caesarean section.

Trial of labour after caesarean section: Two-year analysis at a Portuguese centre

We conducted a retrospective study aimed at determining variables associated with a higher success rate for vaginal delivery after caesarean section, and assessing the impact of induction of labour. Secondarily, we aimed to describe our vaginal delivery and uterine rupture rates with the use of a controlled-release dinoprostone vaginal insert for cervical ripening. Of 292 women who met the inclusion criteria, induction of labour occurred in 48% (94% with dinoprostone). There was a non-significant difference between the vaginal delivery rate of spontaneous labour (57%) and induction of labour (33%), after adjusting for confounding variables. The success rate was influenced by a Bishop score ≥6, previous vaginal delivery and previous caesarean for dystocia or failed induction. There was only one case of uterine rupture, which was associated with dinoprostone use (overall rate 0.34%, 0.77% for dinoprostone). Impact statement Trial of labour after caesarean section is considered an alternative to elective repeat caesarean. Both present associated benefits and risks, the most fearsome of which is uterine rupture during labour (0.78% in term pregnancies). Induction is also possible but carries a higher risk of uterine rupture and lower success rate for vaginal birth. Prostaglandins have been of particular concern due to a higher risk of uterine scar rupture, estimated at 2% for dinoprostone; however, its use as a controlled-release vaginal insert has been under-reported. Our study confirms the reported impact of previous vaginal delivery, previous caesarean indication and Bishop score at admission on success rate for vaginal birth after caesarean. We were unable to prove a lower success rate for induction of labour after adjusting for other variables. Despite our study limitations, we report on the use of a controlled-release vaginal insert with 10mg of dinoprostone in 130 women with a uterine rupture rate of 0.77%, lower than previously reported and similar to the overall rate estimated for term pregnancies. This dinoprostone formulation may be safer than previously reported but larger studies, and preferably randomised controlled trials, are needed to confirm these findings.

Mode of Delivery and Asthma at School Age in 9 European Birth Cohorts

Evidence on the association between mode of delivery and asthma at school age is inconclusive. We assessed the associations between specific modes of delivery and asthma in children from 9 European birth cohorts that enrolled participants between 1996 and 2006. Cohort-specific crude and adjusted risk ratios for asthma at ages 5-9 years were calculated using Poisson regression models and pooled. A sensitivity analysis was carried out in children born at term to reduce confounding due to perinatal factors. The study included 67,613 participants. Cohort-specific rates of cesarean delivery varied from 9.4% to 37.5%. Cesarean delivery, as opposed to vaginal delivery, was associated with an increased risk of asthma (adjusted risk ratio (aRR) = 1.22, 95% confidence interval (CI): 1.02, 1.46). Compared with spontaneous vaginal delivery, the adjusted risk ratio was 1.33 (95% CI: 1.02, 1.75) for elective cesarean delivery, 1.07 (95% CI: 0.94, 1.22) for emergency cesarean delivery, and 0.97 (95% CI: 0.84, 1.12) for operative vaginal delivery. In children born at term, the associations were strengthened only for elective cesarean delivery (aRR = 1.49, 95% CI: 1.13, 1.97). The large sample size allowed analysis of the associations between specific modes of delivery and asthma at school age. The increased risk of asthma associated with elective cesarean delivery, especially among children born at term, is relevant in counteracting the increasing use of this procedure, which is often performed without a clear medical indication.

Clean air matters: an overview of traffic-related air pollution and pregnancy

The right to a healthy pregnancy and to giving birth in a safe environment is source of comprehensive research. Decent birth facilities, respect, and no discrimination are already recognized as fundamental rights, but an accurate look at the outdoor environment is required. Air pollution is a dangerous factor to pregnant women and newborns, many of whom highly exposed to traffic-related atmospheric pollutants in urban areas. Such exposure can lead to low birth weight and long-lasting effects, such as respiratory diseases and premature death. Thus, this commentary, based on the analysis of literature, presents the importance of the exposome concept and of epigenetics in identifying the role of the environment for better health conditions of pregnant women and newborns. In the final considerations, this study proposes the deepening of the subject and the mobilization in this regard, with a human rights-based approach to environmental health and to the increased awareness of pregnant women on the risks of air pollution and its effects on health.

Cesarean Section and Risk of Childhood Acute Lymphoblastic Leukemia in a Population-Based, Record-Linkage Study in California

The relationship of mode of delivery to risk of childhood acute lymphoblastic leukemia (ALL) is uncertain. After linking birth records and cancer registry data from California, we conducted a population-based case-control study to investigate the role of delivery by cesarean section (C-section) in the etiology of childhood ALL. This study included 5,081 cases and 18,927 matched controls born in 1978-2009; more detailed data were available on type of C-section (i.e., elective vs. emergency) for a subset of 1,552 cases and 5,688 controls. No association was observed between C-section overall and childhood ALL risk (<15 years of age), but elective C-section was associated with a significantly elevated risk of ALL (odds ratio (OR) = 1.17, 95% confidence interval (CI): 1.01, 1.36). At the peak ages of ALL incidence (2-4 years), C-section was associated with an 11% higher risk of ALL (OR = 1.11, 95% CI: 1.01, 1.22) compared with vaginal delivery, and the magnitude of the association was larger for elective C-section (OR = 1.38, 95% CI: 1.11, 1.70). Emergency C-section was not associated with childhood ALL. Because of design features minimizing nonparticipation and inaccurate recall, this record linkage-based study is less prone to bias. Our results suggest that delivery by elective C-section was associated with a higher risk of childhood ALL, especially at the peak ages of incidence. It is important to evaluate possible mechanisms, because this potential risk factor is modifiable.

Determinants and materno-fetal outcomes related to cesarean section delivery in private and public hospitals in low- and middle-income countries: a systematic review and meta-analysis protocol

BACKGROUND

Despite the well-established morbidity, mortality, long-term effects, and unnecessary extra-cost burden associated with cesarean section delivery (CSD) worldwide, its rate has grown exponentially. This has become a great topical challenge for the international healthcare community and individual countries. Estimated at three times the acceptable rate as defined by the World Health Organization in 1985, the continued upward trend has been fuelled by higher income countries. Some low- and middle-income countries (LMICs) have now taken the lead, and the factors contributing to this situation are poorly understood. The expansion of the private healthcare sector may be playing a significant role. Distinguishing between the public and private hospitals' role is critical in this investigation as it has not yet been approached. This review aims to systematically synthesize knowledge on the determinants of the CSD rate rise in private and public hospitals in LMICs and to investigate materno-fetal and materno-infant outcomes of CSD in perinatal period, between private and public hospitals.

METHODS/DESIGN

We will include studies published in English, French, Spanish, and Portuguese since 2000, using any experimental design, including randomized controlled trials (RCTs), non-RCTs, quasi-experimental, before and after studies, and interrupted time series. Outcomes of interest are the determinants of CSD and materno-fetal and materno-infant outcomes. We will only include studies carried out in private and public hospitals in LMICs. The literature searches will be conducted in the following databases: MEDLINE, Embase, CINAHL, Cochrane database, LILACS, and HINARI. We will also include unpublished studies in the gray literature (theses and technical reports). Using the two-person approach, two independent review authors will screen eligible articles, extract data, and assess risk of bias. Disagreements will be resolved through discussion with a third author. Results will be presented as structured summaries of the included studies. If possible, a meta-analysis will be conducted and, subsequently, an analysis for heterogeneity will be implemented.

DISCUSSION

The proposed systematic review of the CSD rate rise will provide up-to-date evidence in regard to differences in proportions, determinants, and materno-fetal and materno-infant outcomes in perinatal period, between private and public hospitals in LMICs. We believe that this knowledge synthesis will help to shed light on the evidence and support evidence-informed decision-making with a view to addressing the issue in LMICs.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42016036871.

Cesarean Outcomes in US Birth Centers and Collaborating Hospitals: A Cohort Comparison

INTRODUCTION

High rates of cesarean birth are a significant health care quality issue, and birth centers have shown potential to reduce rates of cesarean birth. Measuring this potential is complicated by lack of randomized trials and limited observational comparisons. Cesarean rates vary by provider type, setting, and clinical and nonclinical characteristics of women, but our understanding of these dynamics is incomplete.

METHODS

We sought to isolate labor setting from other risk factors in order to assess the effect of birth centers on the odds of cesarean birth. We generated low-risk cohorts admitted in labor to hospitals (n = 2527) and birth centers (n = 8776) using secondary data obtained from the American Association of Birth Centers (AABC). All women received prenatal care in the birth center and midwifery care in labor, but some chose hospital admission for labor. Analysis was intent to treat according to site of admission in spontaneous labor. We used propensity score adjustment and multivariable logistic regression to control for cohort differences and measured effect sizes associated with setting.

RESULTS

There was a 37% (adjusted odds ratio [OR], 0.63; 95% confidence interval [CI], 0.50-0.79) to 38% (adjusted OR, 0.62; 95% CI, 0.49-0.79) decreased odds of cesarean in the birth center cohort and a remarkably low overall cesarean rate of less than 5% in both cohorts.

DISCUSSION

These findings suggest that low rates of cesarean in birth centers are not attributable to labor setting alone. The entire birth center care model, including prenatal preparation and relationship-based midwifery care, should be studied, promoted, and implemented by policy makers interested in achieving appropriate cesarean rates in the United States.

The microbiome during pregnancy and early postnatal life

We are changing our concept that the newborn infant emerges from a sterile environment. In-utero colonization may have major impacts on the developing mammal in terms of development of immunity and metabolism that, with epigenetic modifications, will lead to diseases in later life. In addition, the microbial profile that develops during and after birth depends on mode of delivery, type of feeding (human milk versus formula) and various other environmental factors to which the newborn is exposed. The goal of this review is to clarify that the microbiome in the maternal fetal unit as well as the immediate changes that occur as new microbes are acquired postnatally play major roles in subsequent health and disease. Rapidly developing technologies for multi-omic analyses and systems biology are shifting paradigms in both scientific knowledge and clinical care.

Delivery route determines the presence of immune complexes on umbilical cord erythrocytes

OBJECTIVE

Umbilical cord blood offers a unique opportunity to study the basal level of immunoglobulin complexes. This study aims to determine the presence of immune complexes and complement deposition on erythrocytes from umbilical cord blood from normal, full-term pregnancies.

METHODS

In vitro pre-formed IgA, IgG, and IgM complexes were used as positive control for flow cytometry detection, and for C3d deposition. Blood samples (34) of umbilical cord blood taken from vaginal and cesarean deliveries were tested for the presence of immunoglobulin complexes.

RESULTS

Fourteen samples from vaginal deliveries and 20 samples from cesarean deliveries were assessed. IgG and IgM complexes were detected on erythrocytes, whereas no IgA complexes or complement deposition was observed. Interestingly, the percentage of IgG complexes was higher on erythrocytes from vaginal delivery samples compared to those from cesarean deliveries. No other associations between immune complexes and other maternal or newborn variables were found.

CONCLUSIONS

IgG and IgM complexes seem to be normally present on umbilical cord erythrocytes. Erythrocytes from vaginal deliveries have a higher percentage of IgG complexes present compared to that from cesarean deliveries. Since no C3d activity was detected, these complexes are non-pathological and should be part of the newborn's initial innate immune response.

A comparison of intestinal microbiota in a population of low-risk infants exposed and not exposed to intrapartum antibiotics: The Baby & Microbiota of the Intestine cohort study protocol

Background

The intestinal microbiota influences metabolic, nutritional, and immunologic processes and has been associated with a broad range of adverse health outcomes including asthma, obesity and Type 2 diabetes. Early life exposures may alter the course of gut microbial colonization leading to differences in metabolic and immune regulation throughout life. Although approximately 50 % of low-risk full-term infants born in Canada are exposed to intrapartum antibiotics, little is known about the influence of this common prophylactic treatment on the developing neonatal intestinal microbiota. The purpose of this study is to describe the intestinal microbiome over the first 3 years of life among healthy, breastfed infants born to women with low-risk pregnancies at full term gestation and to determine if at 1 year of age, the intestinal microbiome of infants exposed to intrapartum antibiotics differs in type and quantity from the infants that are not exposed.

Methods

A prospectively followed cohort of 240 mother-infant pairs will be formed by enrolling eligible pregnant women from midwifery practices in the City of Hamilton and surrounding area in Ontario, Canada. Participants will be followed until the age of 3 years. Women are eligible to participate in the study if they are considered to be low-risk, planning a vaginal birth and able to communicate in English. Women are excluded if they have a multiple pregnancy or a preterm birth. Study questionnaires are completed, anthropometric measures are taken and biological samples are acquired including eight infant stool samples between 3 days and 3 years of age.

Discussion

Our experience to date indicates that midwifery practices and clients are keen to participate in this research. The midwifery client population is likely to have high rates of breastfeeding and low rates of intervention, allowing us to examine the comparative development of the microbiome in a relatively healthy and homogenous population. Results from this study will make an important contribution to the growing understanding of the patterns of intestinal microbiome colonization in the early years of life and may have implications for best practices to support the establishment of the microbiome at birth.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-016-0724-5) contains supplementary material, which is available to authorized users.

Association Between Cesarean Birth and Risk of Obesity in Offspring in Childhood, Adolescence, and Early Adulthood

IMPORTANCE

Cesarean birth has been associated with higher risk of obesity in offspring, but previous studies have focused primarily on childhood obesity and have been hampered by limited control for confounders.

OBJECTIVE

To investigate the association between cesarean birth and risk of obesity in offspring.

DESIGN, SETTING, AND PARTICIPANTS

A prospective cohort study was conducted from September 1, 1996, to December 31, 2012, among participants of the Growing Up Today Study, including 22 068 offspring born to 15 271 women, followed up via questionnaire from ages 9 to 14 through ages 20 to 28 years. Data analysis was conducted from October 10, 2015, to June 14, 2016.

EXPOSURE

Birth by cesarean delivery.

MAIN OUTCOMES AND MEASURES

Risk of obesity based on International Obesity Task Force or World Health Organization body mass index cutoffs, depending on age. Secondary outcomes included risks of obesity associated with changes in mode of delivery and differences in risk between siblings whose modes of birth were discordant.

RESULTS

Of the 22 068 offspring (20 950 white; 9359 male and 12 709 female), 4921 individuals (22.3%) were born by cesarean delivery. The cumulative risk of obesity through the end of follow-up was 13% among all participants. The adjusted risk ratio for obesity among offspring delivered via cesarean birth vs those delivered via vaginal birth was 1.15 (95% CI, 1.06-1.26; P = .002). This association was stronger among women without known indications for cesarean delivery (adjusted risk ratio, 1.30; 95% CI, 1.09-1.54; P = .004). Offspring delivered via vaginal birth among women who had undergone a previous cesarean delivery had a 31% (95% CI, 17%-47%) lower risk of obesity compared with those born to women with repeated cesarean deliveries. In within-family analysis, individuals born by cesarean delivery had 64% (8%-148%) higher odds of obesity than did their siblings born via vaginal delivery.

CONCLUSIONS AND RELEVANCE

Cesarean birth was associated with offspring obesity after accounting for major confounding factors. Although additional research is needed to clarify the mechanisms underlying this association, clinicians and patients should weigh this risk when considering cesarean delivery in the absence of a clear indication.

Every caesarean section must count

Caesarean section rates (CSR) have climbed over the last three decades but some authors have argued that there is no reason to count them, claiming that this practice may lead to inappropriate attempts to lower CSR. However, there are many adverse effects of CS and these are short, medium and long-term for both mother and baby. There is likely to be an optimal CSR which gives the best perinatal outcomes and unless each caesarean counts, and is counted, CSR will be higher than they need to be for best perinatal outcomes.

Microbiota at the crossroads of autoimmunity

Autoimmune diseases have a multifactorial etiology including genetic and environmental factors. Recently, there has been increased appreciation of the critical involvement of the microbiota in the pathogenesis of autoimmunity, although in many cases, the cause and the consequence are not easy to distinguish. Here, we suggest that many of the known cues affecting the function of the immune system, such as genetics, gender, pregnancy and diet, which are consequently involved in autoimmunity, exert their effects by influencing, at least in part, the microbiota composition and activity. This, in turn, modulates the immune response in a way that increases the risk for autoimmunity in predisposed individuals. We further discuss current microbiota-based therapies.

Cesarean section delivery and development of food allergy and atopic dermatitis in early childhood

BACKGROUND

Delivery by Cesarean section (CS) may predispose to allergic disorders, presumably due to alterations in the establishment of normal gut microbiota in early infancy. In this study, we sought to investigate the association between CS and physician-diagnosed food allergy and atopic dermatitis during the first 3 years of life, using data from a homogeneous, population-based, birth cohort.

METHODS

A total of 459 children born and cared for in the same tertiary maternity unit were examined at birth and followed up at 1, 6, 12, 18, 24, 30 and 36 months of age. Participants with symptoms suggestive of food allergy or atopic dermatitis were evaluated by a pediatric allergy specialist to confirm the diagnosis based on well-defined criteria.

RESULTS

The rate of CS was 50.8% (n = 233). Food allergy was diagnosed in 24 participants (5.2%) while atopic dermatitis was diagnosed in 62 children (13.5%). Cesarean section (OR 3.15; 95% CI 1.14-8.70), atopic dermatitis of the child (OR 3.01; 95% CI 1.18-7.80), parental atopy (OR 4.33; 95% CI 1.73-12.1), and gestational age (OR 1.57; 95% CI 1.07-2.37) were significant and independent predictors of food allergy. Children with at least one allergic parent delivered by CS had higher probability of developing food allergy compared with vaginally delivered children of non-allergic parents (OR 10.0; 95% CI 3.06-32.7). Conversely, the effect of CS on atopic dermatitis was not significant (OR 1.35; 95% CI 0.74-2.47).

CONCLUSIONS

Delivery by CS predisposes to the development of food allergy but not atopic dermatitis in early childhood. Cesarean section delivery seems to upregulate the immune response to food allergens, especially in children with allergic predisposition.

Induced Labor in Sweden, 1999-2012: A Population-Based Cohort Study

BACKGROUND

Previous studies show contradictory results about the impact of induced labor on the cesarean delivery rate and few studies have investigated the risk of vacuum extraction subsequent to induced labor. The aims of the present study were to describe the rate of induced labor in Sweden from 1999 to 2012, and to assess the risk of unplanned cesarean delivery and vacuum extraction after induced labor in relation to medical complications and length of gestation.

METHODS

A register-based cohort study was conducted, including 1,078,536 women with spontaneous or induced onset of labor who gave birth by noninstrumental vaginal delivery, unplanned cesarean delivery, or vacuum extraction in gestational week 37 + 0 to 41 + 6. Logistic regression was used to study the association between induced labor and instrumental delivery.

RESULTS

The rate of induced labor increased from 7.7 to 12.9 percent among primiparous and from 7.5 to 11.8 percent among multiparous women. Induced labor was associated with 2-3 times greater risk of unplanned cesarean delivery among all women, except multiparas in gestational week 37-38, and with a 20-50 percent higher risk of vacuum extraction after the adjustment for confounding factors. Among women without a recognized medical complication, induced labor was associated with a threefold increased risk of cesarean delivery in gestational week 39-41 and a 40 percent increase in gestational week 37-38 compared with women with spontaneous onset of labor.

CONCLUSIONS

The proportion of induced labors increased substantially during the 14-year study period and was associated with an increased risk of both cesarean delivery and vacuum extraction, even in women without a documented medical complication. The increased risk of instrumental delivery should be taken into account when counseling about the risks and benefits of induced labor.

Preconception Care: A New Standard of Care within Maternal Health Services

Emerging research suggests that much pediatric affliction has origins in the vulnerable phase of fetal development. Prenatal factors including deficiency of various nutrients and exposure to assorted toxicants are major etiological determinants of myriad obstetrical complications, pediatric chronic diseases, and perhaps some genetic mutations. With recent recognition that modifiable environmental determinants, rather than genetic predestination, are the etiological source of most chronic illness, modification of environmental factors prior to conception offers the possibility of precluding various mental and physical health conditions. Environmental and lifestyle modification through informed patient choice is possible but evidence confirms that, with little to no training in clinical nutrition, toxicology, or environmental exposures, most clinicians are ill-equipped to counsel patients about this important area. With the totality of available scientific evidence that now exists on the potential to modify disease-causing gestational determinants, failure to take necessary precautionary action may render members of the medical community collectively and individually culpable for preventable illness in children. We advocate for environmental health education of maternity health professionals and the widespread adoption and implementation of preconception care. This will necessitate the translation of emerging knowledge from recent research literature, to health professionals, to reproductive-aged women, and to society at large.

Birth by Caesarean Section and the Risk of Adult Psychosis: A Population-Based Cohort Study

Despite the biological plausibility of an association between obstetric mode of delivery and psychosis in later life, studies to date have been inconclusive. We assessed the association between mode of delivery and later onset of psychosis in the offspring. A population-based cohort including data from the Swedish National Registers was used. All singleton live births between 1982 and 1995 were identified (n= 1,345,210) and followed-up to diagnosis at age 16 or later. Mode of delivery was categorized as: unassisted vaginal delivery (VD), assisted VD, elective Caesarean section (CS) (before onset of labor), and emergency CS (after onset of labor). Outcomes included any psychosis; nonaffective psychoses (including schizophrenia only) and affective psychoses (including bipolar disorder only and depression with psychosis only). Cox regression analysis was used reporting partially and fully adjusted hazard ratios (HR) with 95% confidence intervals (CI). Sibling-matched Cox regression was performed to adjust for familial confounding factors. In the fully adjusted analyses, elective CS was significantly associated with any psychosis (HR 1.13, 95% CI 1.03, 1.24). Similar findings were found for nonaffective psychoses (HR 1.13, 95% CI 0.99, 1.29) and affective psychoses (HR 1.17, 95% CI 1.05, 1.31) (χ(2)for heterogeneityP= .69). In the sibling-matched Cox regression, this association disappeared (HR 1.03, 95% CI 0.78, 1.37). No association was found between assisted VD or emergency CS and psychosis. This study found that elective CS is associated with an increase in offspring psychosis. However, the association did not persist in the sibling-matched analysis, implying the association is likely due to familial confounding by unmeasured factors such as genetics or environment.