Childhood growth trajectories according to combinations of pregestational weight status and maternal smoking during pregnancy: a multilevel analysis

Prenatal Exposure to Multiple Endocrine-Disrupting Chemicals and Childhood BMI Trajectories in the INMA Cohort Study

BACKGROUND

Prenatal exposure to endocrine-disrupting chemicals (EDCs) may disrupt normal fetal and postnatal growth. Studies have mainly focused on individual aspects of growth at specific time points using single chemical exposure models. However, humans are exposed to multiple EDCs simultaneously, and growth is a dynamic process.

OBJECTIVE

The objective of this study was to evaluate the associations between prenatal exposure to EDCs and children's body mass index (BMI) growth trajectories using single exposure and mixture modeling approaches.

METHODS

Using data from the INfancia y Medio Ambiente (INMA) Spanish birth cohort (n = 1,911 ), prenatal exposure to persistent chemicals [hexachlorobenzene (HCB), 4-4'-dichlorodiphenyldichloroethylene (DDE), polychlorinated biphenyls (PCB-138, -150, and -180), 4 perfluoroalkyl substances (PFAS)] and nonpersistent chemicals (8 phthalate metabolites, 7 phenols) was assessed using blood and spot urine concentrations. BMI growth trajectories were calculated from birth to 9 years of age using latent class growth analysis. Multinomial regression was used to assess associations for single exposures, and Bayesian weighted quantile sum (BWQS) regression was used to evaluate the EDC mixture's association with child growth trajectories.

RESULTS

In single exposure models exposure to HCB, DDE, PCBs, and perfluorononanoic acid (PFNA) were associated with increased risk of belonging to a trajectory of lower birth size followed by accelerated BMI gain by 19%-32%, compared with a trajectory of average birth size and subsequent slower BMI gain [e.g., relative risk ratio (RRR) per doubling in DDE concentration = 1.19 (95% CI: 1.05, 1.35); RRR for PFNA = 1.32 (95% CI: 1.05, 1.66)]. HCB and DDE exposure were also associated with higher probability of belonging to a trajectory of higher birth size and accelerated BMI gain. Results from the BWQS regression showed the mixture was positively associated with increased odds of belonging to a BMI trajectory of lower birth size and accelerated BMI gain (odds ratio per 1-quantile increase of the mixture = 1.70 ; credible interval: 1.03, 2.61), with HCB, DDE, and PCBs contributing the most.

DISCUSSION

This study provides evidence that prenatal EDC exposure, particularly persistent EDCs, may lead to BMI trajectories in childhood characterized by accelerated BMI gain. Given that accelerated growth is linked to a higher disease risk in later life, continued research is important. https://doi.org/10.1289/EHP11103.

Low length/weight growth trajectories of early-term infants during the first year: evidence from a longitudinal study in China

OBJECTIVE

To identify common length, weight and body mass index (BMI) growth trajectories of term infants during infancy, and to determine their association with early-term infants.

DESIGN

Prospective longitudinal study.

SETTING

Wuhan, China.

PATIENTS

A total of 4308 term infants (born at 37-41 weeks of gestation) were included. All term infants were single live birth with no defects and birth weight ≥2500 g, and their mothers were permanent residents of Wuhan for more than 2 years. After excluding 887 infants, a total of 3421 term infants (1028 early-term infants born at 37-38 weeks of gestation and 2393 full-term infants born at 39-41 weeks of gestation) entered the statistical analysis stage.

MAIN OUTCOME MEASURES

Patterns of length, weight and BMI growth trajectories by using group-based trajectory modelling.

RESULTS

Three distinct physical growth trajectories were identified as follows: length: low stable (1056, 30.9%), moderate stable (1887, 55.2%) and high increasing (477, 13.9%); weight: low stable (1031, 30.1%), moderate stable (1884, 55.1%) and high increasing (505, 14.8%); BMI: low stable (689, 20.1%), moderate stable (2167, 63.4%) and high increasing (564, 16.5%). Compared with the full-term infants, early-term infants were more likely to remain at low-stable trajectory in length (OR: 1.40; 95% CI: 1.19 to 1.66) and weight (OR:1.29; 95% CI: 1.09 to 1.53). These associations were still statistically significant after adjusting potential confounders and were more evident among girls in the stratified analysis. There was no statistical association between BMI trajectory patterns and gestational age categories.

CONCLUSION

Our results suggested the heterogeneity of term infants existed in length, weight and BMI growth trajectories of early childhood. Compared with full-term birth, early-term birth was related to low length and weight trajectories rather than BMI trajectory. Further research is needed to evaluate the duration of these low trajectories and their possible long-term health effects.

Influence of Maternal Active and Secondhand Smoking during Pregnancy on Childhood Obesity at 3 Years of Age: A Nested Case-Control Study from the Japan Environment and Children's Study (JECS)

Maternal smoking during pregnancy is a risk factor for childhood obesity; however, the combined effect of secondhand smoking during pregnancy on children in the early years is unclear. We examined the effects of maternal active and secondhand smoking during pregnancy on childhood obesity in a large population-based cohort. A nested case–control study originating from the Japan Environment and Children’s Study was performed. The maternal smoking status was collected via self-administered questionnaires during mid/late pregnancy. Obesity in children was determined based on BMI measured at 3 years of age. In total, 4875 cases and 19,491 controls were included in the analyses. Conditional logistic regression models with a significance level of 5% (two-tailed test) were used to test the association. The proportion of mothers who continued smoking and who were exposed to secondhand smoking daily during pregnancy were 3.9% and 13.0% in cases and 2.9% and 10.8% in controls, respectively. Continuous maternal smoking was associated with increased odds of obesity compared to those who never smoked or quit smoking before the pregnancy (adjusted odds ratio, 1.39; 95% confidence interval, 1.01–1.92). The odds increased further when combined with secondhand smoking. The promotion of non-smoking among family members, in public and workplace could benefit pregnant women and offspring.

Tracking Pattern of Total Cholesterol Levels from Childhood to Adolescence in Japan

Aims: This study aimed to evaluate the tracking pattern of serum total cholesterol (TC) levels among Japanese children using data collected continuously for 9 years and examine the relationship between childhood and adulthood TC levels.

Methods: TC levels of 2,608 first grade primary school children enrolled during 1981-2014 from two Japanese towns were measured during annual health check-ups. Nine-year trajectories of estimated TC levels stratified by TC quartiles in the first grade were analyzed using a mixed effects model. Adulthood TC levels were measured in participants who underwent health check-ups in the same area.

Results: Overall, 1,322 boys and 1,286 girls in the first grade of a primary school were followed for 9 years. Trajectories of TC levels during the period stratified by TC quartiles in the first grade differed significantly and did not cross each other for both sexes. Childhood data of 242 adult participants were linked with their adulthood data; the mean of age was late 20s for both sexes. The average TC levels in adulthood increased from the first to the fourth quartile in the first grade. Additionally, trajectories of TC levels differed between boys and girls. The later the admission year, the more elevated the TC levels in girls.

Conclusion: Among Japanese children, TC levels were strongly tracked from childhood to adolescence for 9 years, and elevated TC levels in childhood were related to elevated TC levels in adulthood. Maintaining appropriate TC levels during childhood may be important to prevent future coronary artery diseases.

Association between infertility treatment and intrauterine growth: a multilevel analysis in a retrospective cohort study

OBJECTIVES

This study aimed to identify intrauterine growth differences according to infertility treatment compared with spontaneous conception and to describe intrauterine growth trajectories.

DESIGN

Retrospective cohort study.

SETTING

A single primary and tertiary medical centre in Japan.

PARTICIPANTS

This study included singleton pregnant women with prenatal check-ups and delivery at the University of Yamanashi Hospital between 1 July 2012 and 30 September 2017. Patients were divided into four groups: spontaneous conception, infertility treatment without assisted reproductive technology (ART), fresh-embryo transfer and frozen embryo transfer (FET).

INTERVENTIONS

Differences in intrauterine growth according to the infertility treatment, including ART, and birth weight were evaluated. Multilevel analysis was employed to evaluate intrauterine growth trajectories stratified by the sex of the offspring.

PRIMARY OUTCOME MEASURE

Estimated fetal weight (EFW) assessed by ultrasound examination.

RESULTS

We assessed data from 37 239 prenatal examination results from 2377 pregnant women (spontaneous conception, n=1764; infertility treatment without ART, n=171; fresh-embryo transfer, n=112; and FET, n=330) in the final analysis. Multilevel analysis was adjusted for gestation duration, gestation period, parity, hypertensive disorders of pregnancy, type of infertility treatment, maternal age, smoking status, placenta previa, thyroid disease, gestational diabetes mellitus and the interaction between each potential confounding factor and gestation duration. In male fetuses, the interaction between FET and gestational duration (estimate: 0.36; 95% CI: 0.06 to 0.67) significantly affected the EFW. Similarly, in female fetuses, FET (estimate: -69.85; 95% CI: -112.09 to -27.61) and the interaction between FET and gestation duration (estimate: 0.57; 95% CI: 0.28 to 0.87) significantly affected the EFW.

CONCLUSIONS

This study shows that FET affects intrauterine growth trajectory from the second trimester to term, particularly in female fetuses. Our findings require further prospective research to examine the effect of infertility treatment on fetal growth.

Prenatal Ambient Particulate Matter Exposure and Longitudinal Weight Growth Trajectories in Early Childhood

Air pollution exposure during pregnancy has been associated with impaired fetal growth and postnatal weight gain, but few studies have examined the effect on weight growth trajectories. We examine the association between validated 1 km² resolution particulate matter (PM_2.5) concentrations, averaged over pregnancy, and sex-specific growth trajectories from birth to age six of participants in the Boston-based Children's HealthWatch cohort (4797 participants, 84,283 measures). We compared weight trajectories, predicted using polynomial splines in mixed models, between prenatal PM_2.5 above or below the median (9.5 µg/m³), and examined birth weight as an effect modifier. Females exposed to average prenatal PM_2.5 ≥ 9.5 µg/m³ had higher weights compared to females exposed to < 9.5 µg/m³ throughout the study period (0.16 kg at 24 months, 0.61 kg at 60 months). In males, higher prenatal PM_2.5 exposure was associated with significantly lower weights after 24 months of age, with differences increasing with time (-0.17 at 24 months, -0.72 kg at 60 months). Associations were more pronounced among low birth weight (<2500 g) females, but did not differ by birth weight status in males. Our findings demonstrate the complex association between air pollution exposures and childhood weight trajectories and emphasize the importance of sex-stratified analyses.

Analysing child linear growth trajectories among under-5 children in two Nairobi informal settlements

OBJECTIVE

We sought to identify factors associated with linear growth among under-5 children in two urban informal settlements in Nairobi.

DESIGN

We used longitudinal data for the period 2007-2012 from under-5 children recruited in the two sites between birth and 23 months and followed up until they reached 5 years of age. We fitted a generalized linear model on height-for-age Z-scores using the generalized estimating equations method to model linear growth trajectories among under-5 children. Known for its flexibility, the model provides strong parameter estimates and accounts for correlated observations on the same child.

SETTING

Two urban informal settlements in Nairobi, Kenya.ParticipantsUnder-5 children (n 1917) and their mothers (n 1679).

RESULTS

The findings show that child weight at birth, exclusive breast-feeding and immunization status were key determinants of linear growth among under-5 children. Additionally, maternal characteristics (mother's age, marital status) and household-level factors (socio-economic status, size of household) were significantly associated with child linear growth. There were biological differences in linear growth, as female children were more likely to grow faster than males. Finally, the model captured significant household-level effects to investigate further.

CONCLUSIONS

Findings from the study point to the need to improve the targeting of child health programmes directed at the urban poor population in Nairobi. Specific modifiable determinants of child linear growth, particularly child weight at birth, exclusive breast-feeding, immunization status and mother's background characteristics, should be considered when designing interventions aiming at addressing child health inequities in these settings.

Growth of children in Greenland exceeds the World Health Organization growth charts

AIM

Previous studies have found high rates of stunted linear growth in Greenlandic children. We measured growth patterns in Greenland and compared them with international growth charts.

METHODS

The study cohort comprised 279 healthy children aged 6-10 years in 2012. They participated in two pregnancy and birth cohorts in Greenland and longitudinal growth data as birth was extracted from their medical records. Growth reference ranges were estimated with the lambda-mu-sigma (LMS) method and compared with growth charts from Denmark and the World Health Organization (WHO).

RESULTS

The children's mean length, weight and head circumference were significantly larger than the WHO growth charts (p < 0.001). We found that 21-28% of the children aged zero to one years exceeded the WHO growth chart for length by more than two standard deviations. For weight and head circumference, 9-16% of the children aged 0-10 years and 9-11% of the children from zero to two years exceeded the WHO charts by more than two standard deviations. The Danish references were exceeded to a lesser degree.

CONCLUSION

This study showed that the growth of Greenlandic children up to 10 years was no longer stunted. Major determining factors suggested are genetic admixture, maternal overweight, changes in nutrition and improved health.

Maternal smoking during pregnancy and early development of overweight and growth deficit in children: an analysis of survival

Abstract Objectives: to evaluate the association between smoking during pregnancy and nutritional status. Methods: cohort study with a sample of 460 children in the baseline. The children were assessed four times, being measured for weight and length to be converted in indexes length forage (L/A) and body mass index forage (BMI/A) in Z-score. The time until occurrence of growth deficit and overweight was calculated in days and compared to maternal smoking during pregnancy. To assess the association between smoking during pregnancy and the outcomes, a Hazard Ratio by Cox regression was obtained, adjusting by confounding variables selected from Directed Acyclic Graphs (DAG). Results: the time until occurrence of growth deficit and overweight was lower in children whose mothers smoked during pregnancy. Smoking during pregnancy was a risk factor for length deficit (HR = 2.84; CI95% = 1.42 to 5.70) and for overweight (HR = 1.96; CI95% = 1, 09 to 3.53), even after the adjustment. Conclusions: maternal smoking was a changeable factor associated with anthropometric outcomes, which demonstrates the need for actions to combat smoking during pregnancy in order to prevent early nutritional deviations.

Maternal Metabolic Health Parameters During Pregnancy in Relation to Early Childhood BMI Trajectories

OBJECTIVE

The objective of this study was to evaluate the associations between maternal metabolic parameters and early childhood BMI trajectories.

METHODS

Two thousand two hundred fifty-one children born in Spain between 2004 and 2008 were analyzed. Five BMI z score trajectories from birth to age 4 years were identified by using latent class growth analysis. Multinomial regression assessed the associations between maternal metabolic parameters and offspring's BMI trajectories.

RESULTS

Children in the reference BMI trajectory had average size at birth followed by a slower BMI gain. Maternal prepregnancy obesity was associated with trajectories of accelerated BMI gain departing from either higher (relative risk ratio [RRR] = 1.77; 95% CI: 1.07-2.91) or lower size at birth (RRR = 1.91; 95% CI: 1.17-3.12). Gestational weight gain (GWG) above clinical guidelines was associated with a trajectory of higher birth size followed by accelerated BMI gain (RRR = 2.14; 95% CI: 1.53-2.97). Maternal serum triglycerides were negatively associated with BMI trajectories departing from lower birth sizes. Gestational diabetes, maternal serum cholesterol, and C-reactive protein were unrelated to children's BMI trajectories.

CONCLUSIONS

Maternal prepregnancy obesity, GWG, and serum triglycerides are associated with longitudinal BMI trajectories in early childhood that may increase disease risk in later life. Health initiatives should promote healthy weight status before and during pregnancy to improve maternal and child health.

Association between Maternal Smoking during Pregnancy and Low Birthweight: Effects by Maternal Age

Background

Maternal smoking during pregnancy has been consistently related to low birthweight. However, older mothers, who are already at risk of giving birth to low birthweight infants, might be even more susceptible to the effects of maternal smoking. Therefore, this study aimed to examine the modified association between maternal smoking and low birthweight by maternal age.

Methods

Data were obtained from a questionnaire survey of all mothers of children born between 2004 and 2010 in Okinawa, Japan who underwent medical check-ups at age 3 months. Variables assessed were maternal smoking during pregnancy, maternal age, gestational age, parity, birth year, and complications during pregnancy. Stratified analyses were performed using a logistic regression model.

Results

In total, 92641 participants provided complete information on all variables. Over the 7 years studied, the proportion of mothers smoking during pregnancy decreased from 10.6% to 5.0%, while the prevalence of low birthweight did not change remarkably (around 10%). Maternal smoking was significantly associated with low birthweight in all age groups. The strength of the association increased with maternal age, both in crude and adjusted models.

Conclusions

Consistent with previous studies conducted in Western countries, this study demonstrates that maternal age has a modifying effect on the association between maternal smoking and birthweight. This finding suggests that specific education and health care programs for older smoking mothers are important to improve their foetal growth.