Breastfeeding duration, maternal body mass index, and birth weight are associated with differences in body mass index growth trajectories in early childhood

The mediation effect of breastfeeding duration on the relationship between maternal preconception BMI and childhood nutritional risk

BACKGROUND

Higher maternal preconception body mass index (BMI) is associated with lower breastfeeding duration, which may contribute to the development of poor child eating behaviours and dietary intake patterns (components of nutritional risk). A higher maternal preconception BMI has been found to be associated with higher child nutritional risk. This study aimed to determine whether breastfeeding duration mediated the association between maternal preconception BMI and child nutritional risk.

METHODS

In this longitudinal cohort study, children ages 18 months to 5 years were recruited from The Applied Research Group for Kids (TARGet Kids!) in Canada. The primary outcome was child nutritional risk, using The NutriSTEP®, a validated, parent-reported questionnaire. Statistical mediation analysis was performed to assess whether total duration of any breastfeeding mediated the association between maternal preconception BMI and child nutritional risk.

RESULTS

This study included 4733 children with 8611 NutriSTEP® observations. The mean (SD) maternal preconception BMI was 23.6 (4.4) and the mean (SD) breastfeeding duration was 12.4 (8.0) months. Each 1-unit higher maternal preconception BMI was associated with a 0.081 unit higher nutritional risk (95% CI (0.051, 0.112); p < 0.001) (total effect), where 0.011(95% CI (0.006, 0.016); p < 0.001) of that total effect or 13.18% (95% CI: 7.13, 21.25) was mediated through breastfeeding duration.

CONCLUSION

Total breastfeeding duration showed to mediate part of the association between maternal preconception BMI and child nutritional risk. Interventions to support breastfeeding in those with higher maternal preconception BMI should be evaluated for their potential effect in reducing nutritional risk in young children.

Divergent maturational patterns of the infant bacterial and fungal gut microbiome in the first year of life are associated with inter-kingdom community dynamics and infant nutrition

BACKGROUND

The gut microbiome undergoes primary ecological succession over the course of early life before achieving ecosystem stability around 3 years of age. These maturational patterns have been well-characterized for bacteria, but limited descriptions exist for other microbiota members, such as fungi. Further, our current understanding of the prevalence of different patterns of bacterial and fungal microbiome maturation and how inter-kingdom dynamics influence early-life microbiome establishment is limited.

RESULTS

We examined individual shifts in bacterial and fungal alpha diversity from 3 to 12 months of age in 100 infants from the CHILD Cohort Study. We identified divergent patterns of gut bacterial or fungal microbiome maturation in over 40% of infants, which were characterized by differences in community composition, inter-kingdom dynamics, and microbe-derived metabolites in urine, suggestive of alterations in the timing of ecosystem transitions. Known microbiome-modifying factors, such as formula feeding and delivery by C-section, were associated with atypical bacterial, but not fungal, microbiome maturation patterns. Instead, fungal microbiome maturation was influenced by prenatal exposure to artificially sweetened beverages and the bacterial microbiome, emphasizing the importance of inter-kingdom dynamics in early-life colonization patterns.

CONCLUSIONS

These findings highlight the ecological and environmental factors underlying atypical patterns of microbiome maturation in infants, and the need to incorporate multi-kingdom and individual-level perspectives in microbiome research to improve our understandings of gut microbiome maturation patterns in early life and how they relate to host health. Video Abstract.

Breastfeeding and the Longitudinal Changes of Body Mass Index in Childhood and Adulthood: A Systematic Review

Mounting evidence supports the beneficial role of breastfeeding in lowering obesity risk, but the enduring impact of breastfeeding on longitudinal changes in body mass index (BMI) (i.e., BMI trajectories) remains unclear. This systematic review summarized evidence on how breastfeeding influenced the longitudinal trajectories of BMI later in life. Literature searches were conducted in Medline, Embase, Web of Science, and ScienceDirect to identify studies that assessed how breastfeeding (versus other feeding types or duration) was associated with longitudinal trajectories of BMI or BMI z-score. Three randomized controlled trials (RCTs) and 24 longitudinal cohort studies were included. Two-thirds (18/27) of studies were rated as acceptable or high quality. Most cohort studies (9/11) showed that children who continued to breastfeed at 3 to 12 mo of age had a lower BMI trajectory or lower odds of following a high BMI trajectory than those who were formula-fed or mixed-fed. The BMI differences between breastfeeding and other feeding groups were evident from age 7 mo and remained up to 8 y, and the magnitude of between-group BMI differences increased with age. For breastfeeding duration, 12 out of 15 cohort studies found that longer breastfeeding duration was associated with lower BMI trajectories up to age 18 y. Moreover, beneficial associations were observed for both exclusive and any breastfeeding with BMI trajectory. In contrast, mixed findings were reported from 3 RCTs that compared BMI trajectories from birth to ages 12 to 24 mo between breastfeeding promotion versus control or breastfeeding versus formula-feeding groups. The current review provides further longitudinal evidence from cohort studies that breastfeeding versus formula/mixed feeding or longer breastfeeding duration was associated with lower BMI trajectories. Such associations initiated in early childhood became more apparent with age and were sustained into early adulthood. The existing evidence substantiates the importance of breastfeeding promotion and continuation to support obesity prevention.

Determinants of Anishinabeck infant and early childhood growth trajectories in Northwestern Ontario, Canada: a cohort study

BACKGROUND

The Developmental Origins of Health and Disease (DOHaD) paradigm emphasizes the significance of early life factors for the prevention of chronic health conditions, like type 2 diabetes (T2DM) and obesity, which disproportionately affect First Nations communities in Canada. Despite increasing DOHaD research related to maternal health during pregnancy, early childhood growth patterns, and infant feeding practices with many populations, data from First Nations communities in Canada are limited. In partnership with Sandy Lake First Nation, the aims of this project were to characterize birthweights and growth patterns of First Nations infants/children over the first 6 years of life and to study the impact of maternal and infant social and behavioral factors on birthweight and growth trajectories.

METHODS

We recruited 194 families through community announcements and clinic visits. Infant/child length/height and weight were measured at 1 and 2 weeks; 1, 2, 6, 12, and 18 months; and 2, 3, 4, 5 and 6 years. Maternal and infant/child questionnaires captured data about health, nutrition, and social support. Weight-for-Age z-score (WAZ), Height-for-Age z-score (HAZ), and BMI-for-Age z-score (BAZ) were calculated using WHO reference standards and trajectories were analyzed using generalized additive models. Generalized estimating equations and logistic regression were used to determine associations between exposures and outcomes.

RESULTS

WAZ and BAZ were above the WHO mean and increased with age until age 6 years. Generalized estimating equations indicated that WAZ was positively associated with age (0.152; 95% CI 0.014, 0.29), HAZ was positively associated with birthweight (0.155; 95% CI 0.035, 0.275), and BAZ was positively associated with caregiver's BMI (0.049; 95% CI 0.004, 0.090). There was an increased odds of rapid weight gain (RWG) with exposure to gestational diabetes (OR: 7.47, 95% CI 1.68, 46.22). Almost 70% of parents initiated breastfeeding, and breastfeeding initiation was modestly associated with lower WAZ (-0.18; 95% CI -0.64, 0.28) and BAZ (-0.23; 95% CI -0.79, 0.34).

CONCLUSIONS

This work highlights early life factors that may contribute to T2DM etiology and can be used to support community and Indigenous-led prevention strategies.

New approaches and technical considerations in detecting outlier measurements and trajectories in longitudinal children growth data

BACKGROUND

Growth studies rely on longitudinal measurements, typically represented as trajectories. However, anthropometry is prone to errors that can generate outliers. While various methods are available for detecting outlier measurements, a gold standard has yet to be identified, and there is no established method for outlying trajectories. Thus, outlier types and their effects on growth pattern detection still need to be investigated. This work aimed to assess the performance of six methods at detecting different types of outliers, propose two novel methods for outlier trajectory detection and evaluate how outliers affect growth pattern detection.

METHODS

We included 393 healthy infants from The Applied Research Group for Kids (TARGet Kids!) cohort and 1651 children with severe malnutrition from the co-trimoxazole prophylaxis clinical trial. We injected outliers of three types and six intensities and applied four outlier detection methods for measurements (model-based and World Health Organization cut-offs-based) and two for trajectories. We also assessed growth pattern detection before and after outlier injection using time series clustering and latent class mixed models. Error type, intensity, and population affected method performance.

RESULTS

Model-based outlier detection methods performed best for measurements with precision between 5.72-99.89%, especially for low and moderate error intensities. The clustering-based outlier trajectory method had high precision of 14.93-99.12%. Combining methods improved the detection rate to 21.82% in outlier measurements. Finally, when comparing growth groups with and without outliers, the outliers were shown to alter group membership by 57.9 -79.04%.

CONCLUSIONS

World Health Organization cut-off-based techniques were shown to perform well in few very particular cases (extreme errors of high intensity), while model-based techniques performed well, especially for moderate errors of low intensity. Clustering-based outlier trajectory detection performed exceptionally well across all types and intensities of errors, indicating a potential strategic change in how outliers in growth data are viewed. Finally, the importance of detecting outliers was shown, given its impact on children growth studies, as demonstrated by comparing results of growth group detection.

Maternal Preconception Body Mass Index and Early Childhood Nutritional Risk

BACKGROUND

Risk factors for problematic child eating behaviors and food preferences are thought to begin during the preconception period. It is unknown if maternal preconception body mass index (BMI) is associated with child nutritional risk factors (eg, poor dietary intake and eating behaviors).

OBJECTIVES

We aimed to determine whether maternal preconception BMI was associated with child nutritional risk.

METHODS

In this longitudinal cohort study, a secondary data analysis of children ages 18 mo to 5 y were recruited from The Applied Research Group for Kids (TARGet Kids!), a primary care practice-based research network in Canada. The primary exposure was maternal preconception BMI. The primary outcome was parent-reported child nutritional risk score, measured using the Nutrition Screening for Every Preschooler/Toddler (NutriSTEP), an age-appropriate validated questionnaire. Fitted linear mixed effects models analyzed associations between maternal preconception BMI and child nutritional risk after adjusting for covariates.

RESULTS

This study included 4733 children with 8611 repeated NutriSTEP observations obtained between ages 18 mo to 5 y. The mean (standard deviation [SD]) maternal preconception BMI was 23.6 (4.4), where 73.1% of mothers had a BMI ≤24.9 kg/m2, and 26.9% had a BMI ≥25 kg/m2. The mean (SD) NutriSTEP total score was 13.5 (6.2), with 86.6% at low risk (score <21) and 13.4% at high risk (score ≥21). Each 1 unit increase in maternal preconception BMI was associated with a 0.09 increase in NutriSTEP total score (95% confidence interval [CI]: 0.05, 0.12; P ≤ 0.001). After stratification, each 1 unit increase in maternal BMI was associated with a 0.06 increase in mean NutriSTEP total score (95% CI: 0.007, 0.11; P = 0.025) in toddlers and 0.11 increase in mean NutriSTEP total score (95% CI: 0.07, 0.15; P < 0.001) in preschoolers.

CONCLUSION

Higher maternal preconception BMI is associated with slightly higher NutriSTEP total scores. This provides evidence that the preconception period may be an important time to focus on for improving childhood nutrition. This study was registered at clinicaltrials.gov as NCT01869530.

Centre-based childcare in early childhood and growth in later childhood: a prospective cohort study

BACKGROUND

Attending government-regulated centre-based childcare may influence important health behaviours including dietary quality, physical activity and routines related to child growth. However, the relationship between centre-based childcare and childhood obesity remains unclear.

OBJECTIVES

The primary objective was to evaluate the association between centre-based childcare attendance in early childhood and body mass index z-score (zBMI) in later childhood. Secondary objectives included exploring whether family income, child sex, or non-centre-based setting modified these relationships.

METHODS

A prospective cohort study of children aged 1 to 10 years who participated in the TARGet Kids! cohort was conducted. Linear mixed-effect modelling was used to evaluate the relationship between centre-based childcare attendance (in hours/week) compared to non-centre-based childcare between 1-4 years of age and zBMI between 4 and 10 years of age. Generalised estimating equation modelling was used to explore weight status categories. Models were adjusted for confounders and effect modification was explored.

RESULTS

A total of 3503 children were included. Children who attended centre-based childcare full-time (40 h/week) had 0.11 (95% CI: -0.19, -0.03; p = 0.01) lower zBMI at 4 and 7 years of age and lower odds of overweight and obesity at 4 years (OR 0.78; 95% CI: 0.62, 0.97; p = 0.03), but no evidence of an association was found at 10 years of age. Children from families with income < $50,000CDN who attended centre-based childcare full-time had 0.32 (95% CI: -0.50, -0.14; p = 0.001) lower zBMI and lower odds of overweight and obesity (OR 0.52; 95% CI: 0.28, 0.99; p = 0.05) at 10 years of age.

CONCLUSIONS

Attending centre-based childcare in early childhood was associated with a lower zBMI and odds of overweight and obesity in later childhood. These associations were stronger for children from lower income families. Centre-based childcare may be an early intervention for the prevention of childhood obesity.

CLINICAL TRIAL

Clinical Trial Registry Number: NCT01869530 (clinicaltrials.gov).

Maternal BMI in the preconception period, and association with child zBMI growth rates

BACKGROUND

Elevated body mass index (BMI) and rapid growth in early childhood are important predictors of obesity risk. The association between maternal preconception BMI and child growth rates is unclear.

OBJECTIVES

To assess the association between measured maternal preconception BMI and child age- and sex- standardized WHO BMI z-score (zBMI) growth rates and mean zBMI, in children aged 0-10 years old.

METHODS

A longitudinal cohort study was conducted with children (n = 499) enrolled in The Applied Research Group for Kids (TARGet Kids!) primary care practice-based research cohort. Maternal BMI was measured during the preconception period, defined as the 2 years prior to pregnancy. Repeated measures of child weight and height were obtained between 0 and 10 years of age. Linear mixed models were used to evaluate the association between maternal BMI and child zBMI growth rates and mean zBMI.

RESULTS

Maternal preconception BMI was associated with child zBMI growth rate during some growth periods, with the strongest association from age 0 to 4 months; a 5 kg/m2 higher maternal BMI was associated with 0.031 zBMI SD unit/mo higher growth rate (p = 0.004), and 0.186 SD unit higher mean child zBMI (p = 0.0002).

CONCLUSIONS

Maternal preconception BMI was associated with growth rate and mean zBMI in early childhood. The preconception period may be an important target for health interventions to promote healthy child growth rate and weight outcomes.

Maturational patterns of the infant gut mycobiome are associated with early-life body mass index

Unlike the bacterial microbiome, the role of early-life gut fungi in host metabolism and childhood obesity development remains poorly characterized. To address this, we investigate the relationship between the gut mycobiome of 100 infants from the Canadian Healthy Infant Longitudinal Development (CHILD) Cohort Study and body mass index Z scores (BMIz) in the first 5 years of life. An increase in fungal richness during the first year of life is linked to parental and infant BMI. The relationship between richness pattern and early-life BMIz is modified by maternal BMI, maternal diet, infant antibiotic exposure, and bacterial beta diversity. Further, the abundances of Saccharomyces, Rhodotorula, and Malassezia are differentially associated with early-life BMIz. Using structural equation modeling, we determine that the mycobiome's contribution to BMIz is likely mediated by the bacterial microbiome. This demonstrates that mycobiome maturation and infant growth trajectories are distinctly linked, advocating for inclusion of fungi in larger pediatric microbiome studies.

Paternal BMI in the preconception period, and the association with child zBMI

BACKGROUND

Rapid growth and excess weight in early childhood are associated with obesity risk. While maternal preconception BMI has been identified as a potential risk factor, the role of paternal preconception BMI is less clear.

OBJECTIVES

To examine the association between paternal preconception BMI and age- and sex-standardized WHO BMI z-score (zBMI) growth rates, zBMI, and weight status, in 0- to 10-year-old children. To determine whether these associations differed by child sex and maternal preconception weight status.

METHODS

A longitudinal cohort study was conducted through The Applied Research Group for Kids (TARGet Kids!). Children (n = 218) underwent repeated measures of height and weight from birth to 10 years old. Piecewise linear mixed models were used to assess the association between paternal preconception BMI and child zBMI growth rates (zBMI SD units/month) between 0, 4, 30, 48 and 120 months of age. Linear mixed models were used to examine the association with child zBMI, and logistic generalized estimation equations (GEE) were used to assess the association with child weight status. Child sex and maternal preconception weight status were tested as effect modifiers.

RESULTS

Paternal preconception BMI was associated with child zBMI growth rate, mean zBMI and weight status in boys, but not girls. A 5 kg/m² higher paternal preconception BMI was associated with approximately 0.01 zBMI SD unit/month higher growth rate for boys born to mothers with preconception overweight. Higher paternal BMI was associated with higher mean zBMI and increased odds of overweight and obesity in boys, with greater effects seen when mothers had preconception overweight compared to normal weight.

CONCLUSION

Paternal preconception BMI was associated with child zBMI growth rate, zBMI and weight status in boys, with greater effects when the biological mother had preconception overweight or obesity. Further understanding of sex differences in paternal preconception weight effects in children is needed.

Impact of the COVID-19 pandemic on the digitization of routine pediatric practice in Spain: A nationwide survey study

INTRODUCTION

The COVID-19 pandemic forced a change in the working dynamics of all healthcare professionals, leading to the sudden introduction of telemedicine. Although until that moment telemedicine applications had been described in the paediatric age, their use was anecdotal.

OBJECTIVE

To analyse the experience of Spanish paediatricians after the forced digitization of consultations due to the pandemic.

METHODS

A cross-sectional survey-type study was designed to obtain information from Spanish paediatricians about the changes that took place in the usual clinical practice.

RESULTS

306 health professionals participated in the study Most of them agreed on the use of the internet and social networks during the pandemic, referring to mail or WhatsApp® as usual channels of communication with their patients' families. There was a great agreement among paediatricians that the evaluation of newborns after hospital discharge and establishing methodologies that allow childhood vaccination and the identification of subsidiary patients for face-to-face evaluation were necessary although the limitations of the lockdown. The idea that telephone and digital consultations have optimized the consultation time and that they will probably continue after the end of the pandemic was generally accepted. No changes in adherence to breastfeeding or the start of complementary feeding were referred to, but an increase in the duration of breastfeeding and the appearance of frequent hoaxes in social networks concerning infant feeding were found.

CONCLUSIONS

It is necessary to analyse the impact of telemedicine in paediatric consultations during the pandemic to evaluate its effectiveness and quality to maintain it in routine paediatric practice.

Breastfeeding duration is associated with higher adiposity at 6-8 months of age

Breastfeeding (BF) has been identified as a protective factor against childhood obesity. However, evidence of the association between BF duration and adiposity remains inconclusive. Few studies have been conducted among Southeast Asian infants that have measured body composition during infancy using the gold standard stable isotope method. This study aimed to evaluate the association between BF duration and body composition during infancy. Healthy full-term Thai infants aged 6-8 months (n = 60) receiving exclusive or predominant BF for at least 3 months were recruited. Skinfold thickness (SFT) was measured by well-trained investigators. Body composition was assessed by the deuterium dilution technique. Infants with longer BF duration (>6 months; mean 7.5 ± 0.5 months, n = 29) had a higher subscapular SFT z-score than those with shorter BF duration (≤6 months; mean 5.3± 0.9 months, n = 31) by 0.48 (95% confidence interval [CI]: 0.01-0.94). After adjustment for age and sex, BF duration and age at introduction of complementary feeding (CF) were positively associated with fat mass and fat mass index at 6-8 months. One month increase in BF duration and CF age was associated with a 0.37 (95% CI: 0.05, 0.69) kg/m² and 0.76 (95% CI: 0.18, 1.34) kg/m² increase in the fat mass index, respectively. After adjusting for infant body mass index (BMI) during the earlier infancy period, the strength of the association was attenuated. This finding may reflect reverse causality where infants with lower BMI received formula or CF earlier. A longitudinal study with follow-up into childhood is warranted to confirm the effects of BF on adiposity in infancy and childhood.

Association of Cesarean Delivery with Trajectories of Growth and Body Composition in Preschool Children

This study aimed to examine the association of cesarean delivery with trajectories of growth and body composition in preschool children. This ambidirectional cohort study was conducted between 2017 and 2020 in China. Information on the delivery mode, weight, and length/height of the children measured at routine healthcare visits was obtained from maternal and child health records. For three years while in kindergarten, children’s body mass index (BMI), fat mass index (FMI), fat-free mass index (FFMI), and percentage of body fat (FM%) were repeatedly measured. A BMI z score (zBMI) was calculated and standardized to WHO measures, and overweight and obesity were defined using the WHO reference. After adjustment for maternal age, maternal education, annual family income, prepregnancy BMI, gestational weight gain, gravidity, parity, gestational age, child sex, birthweight, breastfeeding duration, and the parent-reported dietary intake of the children, children born via cesarean delivery (n = 1992) versus those born vaginally (n = 1578) had higher zBMI growth rates beyond 36 months (β: 0.003; 95% CI: 0.001, 0.005 SD units/month) and elevated levels of FMI (β: 0.097; 95% CI: 0.026, 0.168 kg/m²), FM% (β: 0.402; 95% CI: 0.058, 0.745%) and zBMI (β: 0.073; 95% CI: 0.012, 0.133 units), but not FFMI (β: 0.022; 95% CI: −0.022, 0.066 kg/m²). The adjusted OR of overweight and obesity was 1.21 (95% CI: 1.04, 1.40). Cesarean delivery likely elevated zBMI growth rates and increased the risk of overweight and obesity in preschool children, with the elevation of fat mass but not fat-free mass.

Predicting the earliest deviation in weight gain in the course towards manifest overweight in offspring exposed to obesity in pregnancy: a longitudinal cohort study

BACKGROUND

Obesity in pregnancy and related early-life factors place the offspring at the highest risk of being overweight. Despite convincing evidence on these associations, there is an unmet public health need to identify "high-risk" offspring by predicting very early deviations in weight gain patterns as a subclinical stage towards overweight. However, data and methods for individual risk prediction are lacking. We aimed to identify those infants exposed to obesity in pregnancy at ages 3 months, 1 year, and 2 years who likely will follow a higher-than-normal body mass index (BMI) growth trajectory towards manifest overweight by developing an early-risk quantification system.

METHODS

This study uses data from the prospective mother-child cohort study Programming of Enhanced Adiposity Risk in CHildhood-Early Screening (PEACHES) comprising 1671 mothers with pre-conception obesity and without (controls) and their offspring. Exposures were pre- and postnatal risks documented in patient-held maternal and child health records. The main outcome was a "higher-than-normal BMI growth pattern" preceding overweight, defined as BMI z-score >1 SD (i.e., World Health Organization [WHO] cut-off "at risk of overweight") at least twice during consecutive offspring growth periods between age 6 months and 5 years. The independent cohort PErinatal Prevention of Obesity (PEPO) comprising 11,730 mother-child pairs recruited close to school entry (around age 6 years) was available for data validation. Cluster analysis and sequential prediction modelling were performed.

RESULTS

Data of 1557 PEACHES mother-child pairs and the validation cohort were analyzed comprising more than 50,000 offspring BMI measurements. More than 1-in-5 offspring exposed to obesity in pregnancy belonged to an upper BMI z-score cluster as a distinct pattern of BMI development (above the cut-off of 1 SD) from the first months of life onwards resulting in preschool overweight/obesity (age 5 years: odds ratio [OR] 16.13; 95% confidence interval [CI] 9.98-26.05). Contributing early-life factors including excessive weight gain (OR 2.08; 95% CI 1.25-3.45) and smoking (OR 1.94; 95% CI 1.27-2.95) in pregnancy were instrumental in predicting a "higher-than-normal BMI growth pattern" at age 3 months and re-evaluating the risk at ages 1 year and 2 years (area under the receiver operating characteristic [AUROC] 0.69-0.79, sensitivity 70.7-76.0%, specificity 64.7-78.1%). External validation of prediction models demonstrated adequate predictive performances.

CONCLUSIONS

We devised a novel sequential strategy of individual prediction and re-evaluation of a higher-than-normal weight gain in "high-risk" infants well before developing overweight to guide decision-making. The strategy holds promise to elaborate interventions in an early preventive manner for integration in systems of well-child care.

Socioeconomic disparities and infancy growth trajectory: a population-based and longitudinal study

Background

The association of low socioeconomic status (SES) with childhood and adolescent obesity has been reported. It is unknown whether low SES affects body mass index (BMI) growth trajectory in the first 12 mo of life. Moreover, accelerated growth as a compensatory mechanism for low birth weight (LBW) during infancy, is an important predictor of later obesity. The aim of the present study was to examine the association of low SES with infancy BMI growth rate and trajectory for LBW and normal birth weight (NBW) infants.

Methods

From September 2012 to October 2014, a total of 387 infants in this longitudinal study was subjected to repeated measures of weight and length from birth to 12 mo in Hefei. Generalized growth mixture modeling was used to classify the infancy BMI growth trajectories. Differences in infancy BMI z score (zBMI) and BMI growth rate between low SES and high SES were estimated based on linear regression after adjusting for several confounders including maternal age, pregnancy BMI, physical activity during pregnancy, paternal BMI as well as alcohol use, paternal smoking status, breastfeeding duration and delivery mode.

Results

Infancy BMI trajectories in this study were classified into three categories: rapid growth (class 1), normal growth (class 2) and slow growth (class 3). Low SES infants had the higher zBMI than high SES infants for LBW group at age 6 mo [zBMI difference with 95% CI at 6 mo: 0.28(0.03, 0.53); at 12 mo: 0.21(0.01, 0.43)]. Low SES infants had more rapid zBMI growth rate than those with high SES for low birth weight between 0 and 6 months. Controlling for the confounders, these associations remained robust. We found the lower SES in the rapid growth group.

Conclusions

These findings highlighted the impact of low SES on increasing BMI and accelerated growth during early infancy. Health care and relatively optimal family environment in the first 12 mo of life, especially for LBW infants, are benefit to shape the better infancy growth trajectory.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-021-02995-4.

Infant feeding and growth trajectories in early childhood: the application and comparison of two longitudinal modelling approaches

BACKGROUND/OBJECTIVES

The role of infant feeding practices in longitudinal growth trajectories in children remains equivocal. This study utilised two longitudinal approaches to examine the associations of infant feeding mode (breastfeeding, mixed feeding, formula feeding), breastfeeding duration, and the timing of solid foods introduction with body mass index (BMI) z-score in early childhood.

SUBJECTS/METHODS

Secondary analyses of data from the Healthy Beginnings Trial were conducted. Infant feeding practices were reported by mothers at 6, 12, and 24 months of child age. Child weight and length were measured at birth, 12, 24, 42, and 60 months. Two longitudinal approaches: linear spline multilevel model (LSMM) and group-based trajectory modelling (GBTM) were used to describe BMI z-score trajectories and assess its associations with infant feeding practices.

RESULTS

The LSMM approach demonstrated that the breastfeeding group showed lower BMI z-scores from ages 12 to 60 months than the mixed feeding and formula feeding groups. Children who were breastfed for ≥ 6 versus < 6 months exhibited a lower BMI z-score trajectory from ages 12 to 60 months. Results from the GBTM approach revealed that the mixed feeding (OR: 1.83, 95%CI 1.04, 3.21) and the formula feeding group (OR: 2.00, 95%CI 0.67, 5.92) showed a tendency for higher odds of following the "High BMIz" trajectory than the breastfeeding group. Breastfeeding duration ≥6 versus < 6 months was linked with lower odds of following the "High BMIz" trajectory (OR 0.65, 95%CI 0.43, 0.98). Both approaches revealed no evidence of an association between the timing of solid foods introduction and BMI z-score trajectory.

CONCLUSIONS

The two longitudinal approaches revealed similar findings that infant feeding mode and breastfeeding duration, but not the timing of solid foods introduction, were associated with BMI z-score trajectory in early childhood. The findings provide robust longitudinal evidence to encourage and support extended breastfeeding for childhood obesity prevention.

Cohort profile: National Investigation of Birth Cohort in Korea study 2008 (NICKs-2008)

BACKGROUND

An adequate large-scale pediatric cohort based on nationwide administrative data is lacking in Korea.

PURPOSE

This study established the National Investigation of Birth Cohort in Korea study 2008 (NICKs-2008) based on data from a nationwide population-based health screening program and data on healthcare utilization for children.

METHODS

The NICKs-2008 study consisted of the Korean National Health Insurance System (NHIS) and the National Health Screening Program for Infants and Children (NHSPIC) databases comprising children born in 2008 (n=469,248) and 2009 (n=448,459) in the Republic of Korea. The NHIS database contains data on age, sex, residential area, income, healthcare utilization (International Classification of Diseases-10 codes, procedure codes, and drug classification codes), and healthcare providers. The NHSPIC consists of 7 screening rounds. These screening sessions comprised physical examination, developmental screening (rounds 2-7), a general health questionnaire, and age-specific anticipatory guidance.

RESULTS

During the 10-year follow-up, 2,718 children (0.3%) died, including more boys than girls (hazard ratio, 1.145; P<0.001). A total of 848,048 children participated in at least 1 of the 7 rounds of the NHSPIC, while 96,046 participated in all 7 screening programs. A total of 823 infants (0.1%) weighed less than 1,000 g, 3,177 (0.4%) weighed 1,000-1,499 g, 37,166 (4.4%) weighed 1,500-2,499 g, 773,081 (91.4%) weighed 2,500-4,000 g, and 32,016 (5.1%) weighed over 4,000 g. There were 23,404 premature babies (5.5%) in 2008 compared to 23,368 (5.6%) in 2009. The developmental screening test indicated appropriate development in 95%-98% of children, follow-up requirements for 1%-4% of children, and recommendations for further evaluation for 1% of children.

CONCLUSION

The NICKs-2008, which integrates data from the NHIS and NHSPIC databases, can be used to analyze disease onset prior to hospitalization based on information such as lifestyle, eating habits, and risk factors.

Cow's milk fat and child adiposity: a prospective cohort study

BACKGROUND

International guidelines recommend children aged 9 months to 2 years consume whole (3.25%) fat cow's milk, and children older than age 2 years consume reduced (0.1-2%) fat cow's milk to prevent obesity. The objective of this study was to evaluate the longitudinal relationship between cow's milk fat (0.1-3.25%) intake and body mass index z-score (zBMI) in childhood. We hypothesized that higher cow's milk fat intake was associated with lower zBMI.

METHODS

A prospective cohort study of children aged 9 months to 8 years was conducted through the TARGet Kids! primary care research network. The exposure was cow's milk fat consumption (skim (0.1%), 1%, 2%, whole (3.25%)), measured by parental report. The outcome was zBMI. Height and weight were measured by trained research assistants and zBMI was determined according to WHO growth standards. A linear mixed effects model and logistic generalized estimating equations were used to determine the longitudinal association between cow's milk fat intake and child zBMI.

RESULTS

Among children aged 9 months to 8 years (N = 7467; 4699 of whom had repeated measures), each 1% increase in cow's milk fat consumed was associated with a 0.05 lower zBMI score (95% CI -0.07 to -0.03, p < 0.0001) after adjustment for covariates including volume of milk consumed. Compared to children who consumed reduced fat (0.1-2%) milk, there was evidence that children who consumed whole milk had 16% lower odds of overweight (OR = 0.84, 95% CI 0.77 to 0.91, p < 0.0001) and 18% lower odds of obesity (OR = 0.82, 95% CI 0.68 to 1.00, p = 0.047).

CONCLUSIONS

Guidelines for reduced fat instead of whole cow's milk during childhood may not be effective in preventing overweight or obesity.

Identifying longitudinal-growth patterns from infancy to childhood: a study comparing multiple clustering techniques

BACKGROUND

Most studies on children evaluate longitudinal growth as an important health indicator. Different methods have been used to detect growth patterns across childhood, but with no comparison between them to evaluate result consistency. We explored the variation in growth patterns as detected by different clustering and latent class modelling techniques. Moreover, we investigated how the characteristics/features (e.g. slope, tempo, velocity) of longitudinal growth influence pattern detection.

METHODS

We studied 1134 children from The Applied Research Group for Kids cohort with longitudinal-growth measurements [height, weight, body mass index (BMI)] available from birth until 12 years of age. Growth patterns were identified by latent class mixed models (LCMM) and time-series clustering (TSC) using various algorithms and distance measures. Time-invariant features were extracted from all growth measures. A random forest classifier was used to predict the identified growth patterns for each growth measure using the extracted features.

RESULTS

Overall, 72 TSC configurations were tested. For BMI, we identified three growth patterns by both TSC and LCMM. The clustering agreement was 58% between LCMM and TS clusters, whereas it varied between 30.8% and 93.3% within the TSC configurations. The extracted features (n = 67) predicted the identified patterns for each growth measure with accuracy of 82%-89%. Specific feature categories were identified as the most important predictors for patterns of all tested growth measures.

CONCLUSION

Growth-pattern detection is affected by the method employed. This can impact on comparisons across different populations or associations between growth patterns and health outcomes. Growth features can be reliably used as predictors of growth patterns.

Associations of community, famliy and early individual factors with body mass index z-scores trajectories among Chinese children and adolescents

The prevalence of childhood overweight and obesity is increasing. This study aimed to examine trajectories of BMI z-scores among Chinese children and the potential determinants including early individual, family and community factors. Group-based trajectory modeling was employed to identify BMI z-scores trajectories of children aged 2-18 years using the five waves data (2010, 2012, 2014, 2016, and 2018) of the China Family Panel Studies (CFPS). Multivariate logistic regression was conducted to determine the association between early individual, family, community factors and BMI z-scores trajectories of children. We identified three trajectories for boys and girls, named Class 1 as "not-overweight", Class 2 as "persistent rapid descending but overweight during pre-school age", and Class 3 as "rapid rising up to school age and then become-overweight" class. Macrosomia (OR 1.772; 95% CI 1.188-2.644) and being a single child (OR 2.038; 95% CI 1.453-2.859) were more likely to belong in Class 3 among boys. Girls living in the advantaged communities (OR 1.539; 95% CI 1.052-2.252), rural-living (OR 1.558; 95% CI 1.133-2.142) and with none social integration (OR 1.496; 95% CI 1.07-2.091) were more likely to belong in Class 2. There are heterogeneous BMI z-scores trajectories of children aged 2-18, and pre-school age is a critical window that could predict the long-term growth patterns. BMI z-scores trends need to be monitored during pre-school age, focusing on those at higher risk of later overweight obesity status, and targeted interventions at the early individual, family, community levels are essential.

Maternal diet in pregnancy is associated with differences in child body mass index trajectories from birth to adolescence

BACKGROUND

Nutrition in pregnancy and accelerated childhood growth are important predictors of obesity risk. Yet, it is unknown which dietary patterns in pregnancy are associated with accelerated growth and whether there are specific periods from birth to adolescence that are most sensitive to these associations.

OBJECTIVES

To examine the extent to which 3 dietary indices in pregnancy [Dietary Inflammatory Index (DII), Alternate Healthy Eating Index for Pregnancy (AHEI-P), and Mediterranean Diet Score (MDS)] are associated with child BMI z-score (BMI-z) trajectories from birth to adolescence.

METHODS

We examined 1459 mother-child dyads from Project Viva that had FFQ data in pregnancy and ≥3 child BMI-z measurements between birth and adolescence. We used linear spline mixed-effects models to examine whether BMI-z growth rates and BMI z-scores differed by quartile of each dietary index from birth to 1 mo, 1-6 mo, 6 mo to 3 y, 3-10 y, and >10 y.

RESULTS

The means ± SDs for DII (range, -9 to +8 units), AHEI-P (range, 0-90 points), and MDS (range, 0-9 points) were -2.6 ± 1.4 units, 61 ± 10 points, and 4.6 ± 2.0 points, respectively. In adjusted models, children of women in the highest (vs. lowest) DII quartile had higher BMI-z growth rates between 3-10 y (β, 0.03 SD units/y; 95% CI: 0.00-0.06) and higher BMI z-scores from 7 y through 10 y. Children of women with low adherence to a Mediterranean diet had higher BMI z-scores from 3 y through 15 y. Associations of AHEI-P with growth rates and BMI z-scores from birth through adolescence were null.

CONCLUSIONS

A higher DII and a lower MDS in pregnancy, but not AHEI-P results, are associated with higher BMI-z trajectories during distinct growth periods from birth through adolescence. Identifying the specific dietary patterns in pregnancy associated with rapid weight gain in children could inform strategies to reduce child obesity.

Feeding patterns and BMI trajectories during infancy: a multi-ethnic, prospective birth cohort

BACKGROUND

Milk feeding type (exclusive breastfeeding [EBF], formula feeding or mixed feeding) and timing of complementary feeding (CF) have been associated with infant growth. However, studies evaluating their combined role, and the role of ethnicity, are scarce. We examined associations of feeding patterns (milk feeding type combined with timing of CF) with infant body mass index (BMI) trajectories and potential ethnic-specific associations.

METHODS

Infant feeding and BMI data during the 1st year of life from 3524 children (Dutch n = 2880, Moroccan n = 404 and Turkish n = 240) from the Amsterdam Born Children and their Development (ABCD) cohort were used. Six feeding patterns were defined: EBF/earlyCF, EBF/lateCF (reference), formula/earlyCF, formula/lateCF, mixed/earlyCF and mixed/lateCF. A covariate adjusted latent class mixed model was applied to simultaneously model BMI trajectories and associations with feeding patterns. Potential ethnic differences in the associations were studied in a separate model where interactions between ethnicity and feeding patterns were included.

RESULTS

Four distinct BMI trajectories (low, mid-low, mid-high and high) were identified. Feeding pattern of formula/earlyCF was associated with lower odds for low (OR: 0.43; 95% CI: 0.25, 0.76) or mid-high (0.28; 0.16, 0.51) (ref: high) trajectory compared with EBF/lateCF pattern (ref). An ethnic-specific model revealed that among Dutch infants, formula/earlyCF pattern was associated with lower odds for low trajectory (0.46; 0.24, 0.87), whereas among Turkish/Moroccan infants almost all feeding patterns were associated with lower odds for the low trajectory (ref: high).

CONCLUSION

Infant feeding patterns are associated with early BMI trajectories with specific ethnic differences. Future studies should take the role of ethnicity into account in the associations between infant feeding and growth.

World Health Organization growth standards: How do Canadian children measure up?

Background

World Health Organization (WHO) growth standards for children aged 0 to 5 years describe growth under optimal conditions and were adopted for use in Canada in 2012. We are seeking to validate these charts in a well-characterized, longitudinal cohort of healthy, Canadian youngsters, assess tracking over time, and evaluate the prognostic implications of early growth.

Methods

Data from 2,795 mother-infant dyads from the CHILD birth cohort were classified by feeding modality at 6 months as exclusively breastfed, partially breastfed, or formula-fed. WHO z-scores (z) were calculated at birth, 3 months, 1 year, and 3 years. Receiver operator characteristics (ROC) assessed the predictive performance of early weight (WT), weight-for-length (WfL), or body mass index (BMI) z-scores for overweight/obesity at 3 years.

Results

Compared to WHO standards, Canadian children at birth had lower median WfLz (-0.73) and BMIz (-0.29), with more positive scores by 3 years (WfLz=BMIz=0.58). At both 1 and 3 years, formula feeding was associated with higher scores than breastfeeding, even after regression adjustment for covariates. Head circumference z-score was typically positive at all times and regardless of feeding modality. At 1 year, ROC area under the curve was 0.79 for WTz, WfLz, and BMIz, and BMIz>0.88 identified children with increased risk of overweight/obesity (BMIz >2) at age 3 years (20.3% versus 3.0%, P<0.001).

Conclusions

Compared to WHO growth charts, Canadian children at 3 years show an upward shift in BMIz and WfLz, particularly when formula-fed. Infant growth parameters may identify infants with increased risk of overweight/obesity at age 3 years; early recognition may allow targeting infants at higher risk.

Every month matters: longitudinal associations between exclusive breastfeeding duration, child growth and obesity among WIC-participating children

BACKGROUND

Research has found breastfeeding to be protective of obesity; however, this link remains contentious. We examined longitudinal associations between exclusive breastfeeding duration, growth trajectories and obesity at 4 years among children participating in the Special Supplemental Nutrition Program for Women, Infants and Children (WIC), and whether these associations differed in the context of the 2009 WIC food package change, implemented to improve alignment with dietary guidelines and promote breastfeeding.

METHODS

Longitudinal data from 260 935 WIC-participating children in Los Angeles County, California, 2003-2016, were used to assess the relationship between duration of receipt of the fully breastfeeding package (an exclusive breastfeeding proxy) with childhood growth and obesity using mixed effects and Poisson regression models.

RESULTS

Children exclusively breastfed for longer duration had healthier growth trajectories and lower obesity risk at age 4. Compared with infants with no fully breastfeeding package receipt, any receipt (a breastfeeding initiation proxy) was associated with reduced obesity risk. Obesity risk was lowest for boys and girls exclusively breastfed for 7 (risk ratio (RR)=0.73, 95% CI=0.64 to 0.82) and 13 months (RR=0.63, 95% CI=0.58 to 0.69), respectively. Exclusive breastfeeding duration increased, but associations between exclusive breastfeeding duration and growth and obesity were not modified, following the 2009 WIC food package change.

CONCLUSION

Increased duration of exclusive breastfeeding was associated with reduced obesity risk. The greatest incremental benefit was observed going from none to any exclusive breastfeeding, and the maximum cumulative benefit was among children receiving the fully breastfeeding package for more than 6 months. Breastfeeding promotion in WIC remains important for obesity prevention.

Early Infant Feeding and BMI Trajectories in the First 5 Years of Life

OBJECTIVE

This study examined the relative impact of breastfeeding duration and timing of solids introduction on BMI z score (BMIz) trajectory in early childhood.

METHODS

This study conducted secondary analyses of data from the Melbourne Infant Feeding, Activity and Nutrition Trial (InFANT) Program (N = 542), a prospective cohort study with data collected at birth and 3, 9, 18, 42, and 60 months. Linear spline multilevel models were performed.

RESULTS

Differential growth rates were observed from birth to 3 months and from 9 to 18 months by breastfeeding duration (≥ 6 vs. < 6 months) and timing of solids introduction (before vs. after 6 months). Children who were breastfed for ≥ 6 versus < 6 months had lower BMIz at all ages from 3 to 60 months. The difference remained after adjusting for child and maternal factors, and the adjusted mean differences in BMIz at 3, 9, 18, 42, and 60 months were -0.34, -0.44, -0.13, -0.19, and -0.23, respectively. Children who received solids before versus after 6 months of age had higher BMIz at 18 and 42 months, but adjustment for child and maternal factors attenuated these differences.

CONCLUSIONS

Longer breastfeeding duration was associated with lower BMIz to 5 years of age, providing further support for infant feeding guidelines to prolong breastfeeding duration for healthy growth.

Associations Between Delivery Mode and Early Childhood Body Mass Index Z-Score Trajectories: A Retrospective Analysis of 2,685 Children From Mothers Aged 18 to 35 Years at Delivery

Objective: To investigate the association between cesarean delivery (CD) and trajectory patterns of age- and sex-specific body mass index (BMI) z-score in early childhood. Methods: A retrospective cohort study was conducted among 2,685 children whose maternal age at the time of birth was between 18 and 35 years, and birth data and anthropometric measurement data during their ages 3-60 months were collected. A group-based trajectory modeling approach was used to identify distinct BMI z-score trajectories, and multinomial logistic regressions were applied to estimate the associations among CD (both elective and non-elective combined), elective and non-selective CD, and BMI z-score trajectory classes. Results: Of the 2,685 participants, 46.5% (N = 1,248) were born by vaginal delivery (VD), 20.7% (N = 556) by elective CD, and 32.8% (N = 881) by non-elective CD. Five BMI z-score trajectory patterns were identified, and they were "increasing from moderate to high" (10.1%, n = 270), "increasing from mild to moderate" (34.2%, n = 919), "increasing from low to high" (10.5%, n = 283), "stable mild" (30.1%, n = 808), and "stable low" (15.1%, n = 405) groups. Compared with children delivered by VD, those who delivered by CD (both elective and non-elective combined), elective CD, and non-elective CD were associated with the "increasing from moderate to high" trajectory [odds ratio (OR) = 1.61, 95% confidence interval (CI): 1.13-2.29; OR = 1.64, 95%CI: 1.06-2.54; and OR = 1.59, 95%CI: 1.05-2.39, respectively] and were also associated with the "increasing from low to high" trajectory (OR = 1.60, 95%CI: 1.17-2.19, OR = 1.75, 95%CI: 1.16-2.63; and OR = 1.53, 95%CI: 1.00-2.34, respectively). Conclusion: Both elective and non-elective CD were associated with the risk of accelerated weight gain in early childhood.

Early life cognitive development trajectories and intelligence quotient in middle childhood and early adolescence in rural western China

The relationship of cognitive developmental trajectories during the dynamic first years with later life development outcomes remains unclear in low- and middle-income countries. 1388 Children born to women who participated in a randomized trial of antenatal micronutrient supplementation in rural China were prospectively followed. Cognitive development was assessed six times between 3 and 30 months of age using Bayley Scales of Infant Development, and then in mid-childhood (7–9 years) and early adolescence (10–12 years) using Wechsler Intelligence Scale for Children. We identified four distinct infant cognitive development trajectory subgroups using group-based trajectory modeling: (i) consistently above average, (ii) consistently average, (iii) started below average and then improved, and (iv) started below average and then declined. LBW infants (<2500 g) were 10.60 times (95% CI 3.57, 31.49) more likely to be in the trajectory group that started below average and then declined, while each grade increase in maternal education decreased the risk of being in this group by 73% (95% CI 54%, 84%). Infants who performed consistently above average had 8.02 (95% CI 1.46, 14.59) points higher IQ in adolescence versus the declining trajectory group. These findings suggest that interventions to improve early child development trajectories may produce long-term human capital benefits.

Postnatal growth in children born small for gestational age with and without smoking mother

BACKGROUND

Maternal smoking impairs fetal growth; however, if postnatal growth differs between children born small for gestational age (SGA) with smoking and non-smoking mother is unknown.

METHODS

Cohort-study of term born children born appropriate for gestational age with non-smoking mother (AGA-NS, n = 30,561), SGA (birthweight <10^th percentile) with smoking mother (SGA-S, n = 171) or SGA with non-smoking mother (SGA-NS, n = 1761). Means of height and weight measurements, collected at birth, 1.5, 3, 4, and 5 years, were compared using a generalized linear mixed effect model. Relative risks of short stature (<10^th percentile) were expressed as adjusted risk ratios (aRR).

RESULTS

At birth, children born SGA-S were shorter than SGA-NS, but they did not differ in weight. At 1.5 years, SGA-S had reached the same height as SGA-NS. At 5 years, SGA-S were 1.1 cm taller and 1.2 kg heavier than SGA-NS. Compared with AGA-NS, SGA-S did not have increased risk of short stature at 1.5 or 5 years, while SGA-NS had increased risk of short stature at both ages; aRRs 3.0 (95% CI 2.6;3.4) and 2.3 (95% CI 2.0;2.7), respectively.

CONCLUSIONS

Children born SGA-S have a more rapid catch-up growth than SGA-NS. This may have consequences for metabolic and cardiovascular health in children with smoking mothers.

Association of accelerated body mass index gain with repeated measures of blood pressure in early childhood

Background/objectives

We examined the association for rates of age- and sex-standardized body mass index (zBMI) gain between 0–3, 3–18, and 18–36 months with BP in children at 36–72 months of age.

Methods

We collected repeated measures of zBMI and BP in 2502 children. zBMI was calculated using the World Health Organization standards. Each child’s zBMI at birth and rates of zBMI gain in each period from birth to 36 months were estimated using linear spline multilevel models. Generalized estimating equations were used to determine whether zBMI at birth and zBMI gain between 0–3, 3–18, and 18–36 months were each associated with repeated measures of BP at 36–72 months of age. We sequentially conditioned on zBMI at birth and zBMI gain in each period prior to each period tested, as covariates, and adjusted for important socio-demographic, familial, and study design covariates. We examined whether these associations were modified by birthweight or maternal obesity, by including interaction terms.

Results

After adjusting for all covariates and conditioning on prior zBMI gains, a 1 standard deviation unit faster rate of zBMI gain during 0–3 months, (β = 0.59 mmHg; 95% CI 0.31, 0.86) and 3–18 months (β = 0.74 mmHg; 95% CI 0.46, 1.03) were each associated with higher systolic BP at 36–72 months. No significant associations were observed, however, for zBMI at birth or zBMI gain in the 18–36 month growth period. zBMI gains from 0–3 and 3–18 months were also associated with diastolic BP. Birthweight significantly modified the relationship during the 3–18 month period (p = 0.02), with the low birthweight group exhibiting the strongest association for faster rate of zBMI gain with higher systolic BP (β = 1.31 mmHg; 95% CI 0.14, 2.48).

Conclusions

Given that long-term exposure to small elevations in BP are associated with subclinical cardiovascular disease, promoting interventions targeting healthy growth in infancy may be important.

Repeated Measurements of Paraben Exposure during Pregnancy in Relation to Fetal and Early Childhood Growth

Parabens are potential endocrine disruptors with short half-lives in the human body. To date, few epidemiological studies regarding repeated paraben measurements during pregnancy associated with fetal and childhood growth have been conducted. Within a Chinese prenatal cohort, 850 mother-infant pairs from whom a complete set of maternal urine samples were acquired during three trimesters were included, and the levels of five parabens were measured. We assessed the associations of both average and trimester-specific urinary paraben levels with weight and height z-scores at birth, 6 months, 1, and 2 years of age. In all infants, each doubling increase in average ethyl paraben (EtP) was associated with -2.82% (95% CI: -5.11%, -0.53%) decrease in weight z-score at birth, whereas no significant age-specific associations were identified. After stratifying by sex, we further observed age-specific association of average EtP with -3.96% (95% CI: -7.03%, -0.89%) and -3.38% (95% CI: 6.72%, -0.03%) reduction in weight z-scores at 1 and 2 years in males, respectively. Third-trimester EtP was negatively associated with weight z-scores at birth, 1 and 2 years in males. Our results suggested negative associations between prenatal paraben exposure and fetal and childhood growth, and the third trimester may be the window of susceptibility.