Gestation at birth, mode of birth, infant feeding and childhood hospitalization with infection

A Scoping Review of the Relationship Between Maternal BMI and Offspring Incidence of Respiratory Infection: Where Do We Go From Here?

Introduction

Pregnancy complications, including high maternal BMI, are associated with altered early development and child health outcomes. A growing body of work links the prenatal environment, specifically maternal BMI, with respiratory infections in offspring. In this rapid review, the authors review the literature supporting the hypothesis that high maternal BMI during pregnancy is associated with childhood respiratory infection incidence.

Methods

The authors employed systematic search criteria in known databases-EMBASE, EMCARE, MEDLINE, CINAHL, and PsychINFO-searching from inception to January 2023. Included were primary research studies that involved (1) human pregnancy, (2) pregravid or gestational overweight or obesity, and (3) childhood respiratory infection with or without hospitalization.

Results

Only 7 population-based cohort studies met the criteria, investigating maternal BMI as an exposure and childhood respiratory infection as an outcome (age 6 months to 18 years). Therefore, the authors conducted a qualitative analysis, and outcomes were reported. The authors found that >85% of the albeit few published studies support the hypothesis that maternal BMI may have independent and profound consequences on respiratory infection risk across childhood.

Discussion

This area of research needs large-scale, well-controlled studies to better understand the relationship between maternal BMI and childhood respiratory infection. Possible resources such as cohort catalogs and combined databases are discussed. These findings add to the growing evidence that early environmental factors influence lifelong respiratory health. By incorporating a life course approach to infectious disease risk, policy makers can put this research to work and target health vulnerabilities before they arise.

Infant Mode of Delivery Shapes the Skin Mycobiome of Prepubescent Children

Characterizing the skin mycobiome is necessary to define its association with the host immune system, particularly in children. In this study, we describe the skin mycobiome on the face, ventral forearm, and calf of 72 prepubescent children (aged 1 to 10 years) and their mothers, based on internal transcribed spacer (ITS) amplicon sequencing. The age and delivery mode at birth are the most influential factors shaping the skin mycobiome. Compared with that of the vaginally born children, the skin mycobiome of caesarean-born children is assembled by predominantly deterministic niche-based processes and exhibits a more fragile microbial network at all three sampling sites. Moreover, vaginal delivery leads to clearer intra- and interindividual specialization of fungal structures with increasing age; this phenomenon is not observed in caesarean-born children. The maternal correlation with children also differs based on the mode of delivery; specifically, the mycobiomes of vaginally born children at younger ages are more strongly correlated with vagina-associated fungal genera (Candida and Rhodotorula), whereas those of caesarean-delivered children at elder age include more skin-associated and airborne fungal genera (Malassezia and Alternaria). Based on this ecological framework, our results suggest that the delivery mode is significantly associated with maturation of the skin fungal community in children. IMPORTANCE Human skin is permanently colonized by microbes starting at birth. The hygiene hypothesis suggests that a lack of early-life immune imprinting weakens the body's resilience against atopic disorders later in life. To better understand fungal colonization following early-life periods affected by interruption, we studied the skin mycobiomes of 73 children and their mothers. Our results suggest a differentiation of the skin mycobiomes between caesarean-born and vaginally born children. Caesarean-born children exhibit a mycobiome structure with more fitted deterministic niche-based processes, a fragile network, and an unchanged microbial dissimilarity over time. In vaginally born children, this dissimilarity increases with age. The results indicate that initial microbial colonization has a long-term impact on a child's skin mycobiome. We believe that these findings will inspire further investigations of the "hygiene hypothesis" in the human microbiome, especially in providing novel insights into influences on the development of the early-life microbiome.

Association between maternal serum concentration of perfluoroalkyl substances (PFASs) at delivery and acute infectious diseases in infancy

BACKGROUND

Perfluoroalkyl substances (PFASs) are persistent and bio-accumulative compounds that have been recognized as important immune hazards by animal studies. However, epidemiological studies regarding the impact on infant infections were inconsistent.

OBJECTIVES

We investigated the associations between prenatal exposure to PFASs and acute infectious diseases including common cold, bronchitis/pneumonia, and diarrhea in early childhood.

METHODS

Participating 235 mother-infant pairs were recruited from the Laizhou Wan (Bay) birth cohort (LWBC), a prospective study in Shandong, China between September 2010 and 2013. Ten selected PFASs congeners including PFOA, PFOS, PFNA, PFDA, PFUA, PFDoA, PFHxS, PFBS, PFHpA, and PFOSA were measured from maternal serum by HPLC-MS/MS. Detailed information on parent-reported frequency of acute infectious diseases was collected from questionnaires at 1-year follow-up, which was confirmed by the medical records. Logistic and Poisson regression models were used on binary health outcomes (yes/no) and the number of episodes of outcomes, which were reported as odds ratio (OR) and incidence rate-ratio (IRR), respectively.

RESULTS

The risk of diarrhea increased by 4.99 (95% CI = 1.86, 13.39) per log-unit increase in PFOA. The frequencies of diarrhea increased by 97%-116% for each 10-fold increase in PFOA, PFNA, and PFDA. Moreover, when stratified by exclusively breastfeeding duration (at least 4 months or not), the adverse effects of PFASs exposures on diarrhea were more pronounced among the breastfed infants. There were no associations between prenatal PFASs exposure and common cold or bronchitis/pneumonia.

CONCLUSIONS

Exposure to PFASs was associated with increased risks of diarrhea during the first year of life, and these effects were stronger among the breastfed infants. Due to the small sample size, our results should be interpreted with caution and additional studies on larger populations are needed to confirm our findings.

Beneficial Effects of Limosilactobacillus fermentum CECT 5716 Administration to Infants Delivered by Cesarean Section

Cesarean section (CS) disrupts the natural microbiota colonization process in infants, which might compromise immune system maturation, leading to a higher risk of infections. We evaluated the effect of the probiotic Limosilactobacillus (L.) fermentum CECT 5716 on the incidence of gastrointestinal and respiratory infections in the CS infant subgroups (n = 173) of three randomized clinical trials in which this probiotic strain was demonstrated to be safe and effective for preventing infections. Therefore, the data for the CS infants were extracted to obtain the incidence rate ratio (IRR) and 95% CI for gastrointestinal and respiratory infections for each study and were then combined to obtain a pooled IRR and 95% CI using the generic inverse variance method. There was a significant reduction of 73% in the incidence of gastrointestinal infections in CS infants receiving L. fermentum CECT 5716 compared with those receiving the control formula [n = 173, IRR: 0.27 (0.13, 0.53), p = 0.0002]. Regarding respiratory infections, although pooled results showed a reduction of 14% in the probiotic group, the difference was not statistically significant [n = 173, IRR (95% CI): 0.86 (0.67, 1.11), p = 0.25]. In conclusion, the administration of L. fermentum CECT 5716 to CS-born infants protects them from gastrointestinal infections by reducing the risk by up to 73% in this population.

Early-Life Respiratory Infections in Infants with Cow's Milk Allergy: An Expert Opinion on the Available Evidence and Recommendations for Future Research

Acute respiratory infections are a common cause of morbidity in infants and young children. This high rate of respiratory infections in early life has a major impact on healthcare resources and antibiotic use, with the associated risk of increasing antibiotic resistance, changes in intestinal microbiota composition and activity and, consequently, on the future health of children. An international group of clinicians and researchers working in infant nutrition and cow's milk allergy (CMA) met to review the available evidence on the prevalence of infections in healthy infants and in those with allergies, particularly CMA; the factors that influence susceptibility to infection in early life; links between infant feeding, CMA and infection risk; and potential strategies to modulate the gut microbiota and infection outcomes. The increased susceptibility of infants with CMA to infections, and the reported potential benefits with prebiotics, probiotics and synbiotics with regard to improving infection outcomes and reducing antibiotic usage in infants with CMA, makes this a clinically important issue that merits further research.

Associations between gestational age at birth and infection-related hospital admission rates during childhood in England: Population-based record linkage study

BACKGROUND

Children born preterm (<37 completed weeks' gestation) have a higher risk of infection-related morbidity than those born at term. However, few large, population-based studies have investigated the risk of infection in childhood across the full spectrum of gestational age. The objectives of this study were to explore the association between gestational age at birth and infection-related hospital admissions up to the age of 10 years, how infection-related hospital admission rates change throughout childhood, and whether being born small for gestational age (SGA) modifies this relationship.

METHODS AND FINDINGS

Using a population-based, record-linkage cohort study design, birth registrations, birth notifications and hospital admissions were linked using a deterministic algorithm. The study population included all live, singleton births occurring in NHS hospitals in England from January 2005 to December 2006 (n = 1,018,136). The primary outcome was all infection-related inpatient hospital admissions from birth to 10 years of age, death or study end (March 2015). The secondary outcome was the type of infection-related hospital admission, grouped into broad categories. Generalised estimating equations were used to estimate adjusted rate ratios (aRRs) with 95% confidence intervals (CIs) for each gestational age category (<28, 28-29, 30-31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 and 42 weeks) and the models were repeated by age at admission (<1, 1-2, 3-4, 5-6, and 7-10 years). An interaction term was included in the model to test whether SGA status modified the relationship between gestational age and infection-related hospital admissions. Gestational age was strongly associated with rates of infection-related hospital admissions throughout childhood. Whilst the relationship attenuated over time, at 7-10 years of age those born before 40 weeks gestation were still significantly higher in comparison to those born at 40 weeks. Children born <28 weeks had an aRR of 6.53 (5.91-7.22) during infancy, declining to 3.16 (2.50-3.99) at ages 7-10 years, in comparison to those born at 40 weeks; whilst in children born at 38 weeks, the aRRs were 1·24 (1.21-1.27) and 1·18 (1.13-1.23), during infancy and aged 7-10 years, respectively. SGA status modified the effect of gestational age (interaction P<0.0001), with the highest rate among the children born at <28 weeks and SGA. Finally, study findings indicated that the associations with gestational age varied by subgroup of infection. Whilst upper respiratory tract infections were the most common type of infection experienced by children in this cohort, lower respiratory tract infections (LRTIs) (<28 weeks, aRR = 10.61(9.55-11.79)) and invasive bacterial infections (<28 weeks, aRR = 6.02 (4.56-7.95)) were the most strongly associated with gestational age at birth. Of LRTIs experienced, bronchiolitis (<28 weeks, aRR = 11.86 (10.20-13.80)), and pneumonia (<28 weeks, aRR = 9.49 (7.95-11.32)) were the most common causes.

CONCLUSIONS

Gestational age at birth was strongly associated with rates of infection-related hospital admissions during childhood and even children born a few weeks early remained at higher risk at 7-10 years of age. There was variation between clinical subgroups in the strength of relationships with gestational age. Effective infection prevention strategies should include focus on reducing the number and severity of LRTIs during early childhood.

Australia's persistently high rate of early-term prelabour Caesarean delivery

Objective To compare the incidence of prelabour Caesarean delivery (PCD) at early term (37 weeks and 0 days (370) to 38 weeks and 6 days (386) of gestation) between Australian states and hospital sectors over time and to compare these rates with those of England and the United States of America (USA). Method A population-based descriptive study of 556040 singleton PCDs at term (370-406 weeks) in all public and private hospitals in Australian states, 2005-16, was performed. The primary outcome was the early-term PCD rate, defined as early-term PCDs as a percentage of all term PCDs. Results Across Australian states, the early-term PCD rate fell from 56.4% in 2005 to 52.0% in 2016. Over a similar period, England's rate fell from 48.2% in 2006-07 to 35.2% in 2016-17, while the USA's rate fell from 47.4% in 2006 to 34.2% in 2016. Australian public hospitals reduced their rate from 54.2% in 2005 to 44.7% in 2016, but the rate increased in private hospitals from 59.1% in 2005 to 62.5% in 2016. There was considerable variation between states and hospital sectors. Conclusions The early-term PCD rate increased in Australian private hospitals from 2005 to 2016. The public hospital rate fell by nearly 10% over the period but remained ~10% above the English and USA national rates. What is known about the topic? Babies born at early term (370-386 weeks) are at greater risk of morbidity than babies born at full term (390-406 weeks). Australia has a persistently high rate of early-term prelabour Caesarean delivery (PCD). What does this paper add? This paper reveals concerning differences in the early-term PCD rate between Australian states and hospital sectors. Further, the paper highlights that both Australian hospital sectors (public and private) have not reduced their rates to levels achieved in England and the USA. What are the implications for practitioners? These results should inform efforts to reduce Australia's early-term PCD rate to prevent harm to babies.

Anthropometry: A clue for Otorhinolaryngology surgical indications in children

BACKGROUND

There are reports in literature concerning the relation between some maternal and neonatal factors and future risk of disease, including atopy, recurrent infections and obstructive sleep disturbances, three common pathologies eliciting surgery in children.

OBJECTIVE

To evaluate if maternal and neonatal factors can relate to Otorhinolaryngology surgical indications in a cohort of children treated in a tertiary referral center.

MATERIAL AND METHODS

A retrospective analysis of data from children submitted to primary Otorhinolaryngology surgery in the pediatric ambulatory unit of Centro Hospitalar Universitário do Porto between March 2016 and March 2020 was performed. Children with orofacial congenital anomalies were excluded and 1256 children met the eligibility criteria. The associations between maternal and neonatal factors and the development of atopy, recurrent infections and obstructive sleep apnea were analyzed.

RESULTS

Atopic children showed higher birth weight percentile (p < 0,001) and birth weight-for-length index (p < 0,001) compared with non-atopic. Weight-at-surgery was also higher in atopic patients (p = 0,002). Maternal atopy significantly increased the risk of children atopic disease (p < 0,001; Odds Ratio 4,359). Children indicated for surgery for recurrent infections showed lower birth weight-for-length index (p = 0,038) and lower probability of atopic disease (p < 0,001). Recurrent acute otitis media related to both lower birth weight-for-length index (p = 0,002) and birth body mass index (p = 0,023). There was not a significant higher incidence of sleep apnea in preterm infants (p = 0,488). Obstructive sleep apnea patients showed lower weight-at-surgery percentile (p = 0,045).

CONCLUSION

This work suggests an association between birth anthropometric measurements and atopic and infectious diseases later in life, irrespective of gestational age. There was no consistent association between perinatal parameters and obstructive sleep apnea, but the impact of disordered breathing in childhood anthropometry was significative.

Mode of birth and risk of infection-related hospitalisation in childhood: A population cohort study of 7.17 million births from 4 high-income countries

BACKGROUND

The proportion of births via cesarean section (CS) varies worldwide and in many countries exceeds WHO-recommended rates. Long-term health outcomes for children born by CS are poorly understood, but limited data suggest that CS is associated with increased infection-related hospitalisation. We investigated the relationship between mode of birth and childhood infection-related hospitalisation in high-income countries with varying CS rates.

METHODS AND FINDINGS

We conducted a multicountry population-based cohort study of all recorded singleton live births from January 1, 1996 to December 31, 2015 using record-linked birth and hospitalisation data from Denmark, Scotland, England, and Australia (New South Wales and Western Australia). Birth years within the date range varied by site, but data were available from at least 2001 to 2010 for each site. Mode of birth was categorised as vaginal or CS (emergency/elective). Infection-related hospitalisations (overall and by clinical type) occurring after the birth-related discharge date were identified in children until 5 years of age by primary/secondary International Classification of Diseases, 10th Revision (ICD-10) diagnosis codes. Analysis used Cox regression models, adjusting for maternal factors, birth parameters, and socioeconomic status, with results pooled using meta-analysis. In total, 7,174,787 live recorded births were included. Of these, 1,681,966 (23%, range by jurisdiction 17%-29%) were by CS, of which 727,755 (43%, range 38%-57%) were elective. A total of 1,502,537 offspring (21%) had at least 1 infection-related hospitalisation. Compared to vaginally born children, risk of infection was greater among CS-born children (hazard ratio (HR) from random effects model, HR 1.10, 95% confidence interval (CI) 1.09-1.12, p < 0.001). The risk was higher following both elective (HR 1.13, 95% CI 1.12-1.13, p < 0.001) and emergency CS (HR 1.09, 95% CI 1.06-1.12, p < 0.001). Increased risks persisted to 5 years and were highest for respiratory, gastrointestinal, and viral infections. Findings were comparable in prespecified subanalyses of children born to mothers at low obstetric risk and unchanged in sensitivity analyses. Limitations include site-specific and longitudinal variations in clinical practice and in the definition and availability of some data. Data on postnatal factors were not available.

CONCLUSIONS

In this study, we observed a consistent association between birth by CS and infection-related hospitalisation in early childhood. Notwithstanding the limitations of observational data, the associations may reflect differences in early microbial exposure by mode of birth, which should be investigated by mechanistic studies. If our findings are confirmed, they could inform efforts to reduce elective CS rates that are not clinically indicated.