Associations between lifestyle interventions during pregnancy and childhood weight and growth: a systematic review and meta-analysis

Effectiveness of nutritional counseling with overweight pregnant women on child growth at 6 months: A randomized controlled trial

OBJECTIVE

Studies that have investigated the effect of nutritional counseling during the prenatal period on the follow-up outcomes of children at 6 mo have produced inconclusive results. The present study aimed to investigate the effect of nutritional counseling, based on the NOVA food classification, encouraging the consumption of fresh and minimally processed foods, with overweight adult pregnant women on infant growth at 6 mo of age.

METHODS

A randomized controlled trial with 195 pairs of pregnant overweight women and their infants at 6 mo of age was conducted in a Brazilian municipality. The pregnant women were allocated to the control group (CG) or intervention group (IG) at the beginning of the pregnancy. The IG received three sessions of nutrition counseling throughout the pregnancy. Linear regression models were used to investigate the effect of the nutritional counseling on infant growth.

RESULTS

One hundred ninety-five mother-infant pairs with complete data were included (96 CG, and 99 IG). The mean ± SD infant weight (g) at 6 mo was 7856.1 ± 1.1, and length (cm) was 67.0 ± 2.9. There were no differences in maternal and newborn characteristics between the groups. In the linear regression models, the counseling had no effect on anthropometric parameters of the infants at 6 mo of age: weight-for-length Z-score (β 0.089 [95% CI -0.250; 0.427], P = 0.61); length-for-age Z-score (β 0.032 [95% CI -0.299; 0.363], P = 0.85); weight-for-age Z-score (β 0.070 [95% CI -0.260; 0.400], P = 0.68); BMI-age Z-score (β 0.072 [95% CI -0.270; 0.414], P = 0.68).

CONCLUSIONS

There was no effect on infant growth at 6 mo of age after the nutritional counseling during pregnancy. Future studies are needed to confirm this hypothesis.

Epigenetics of the non-coding RNA nc886 across blood, adipose tissue and skeletal muscle in offspring exposed to diabetes in pregnancy

BACKGROUND

Diabetes in pregnancy is associated with increased risk of long-term metabolic disease in the offspring, potentially mediated by in utero epigenetic variation. Previously, we identified multiple differentially methylated single CpG sites in offspring of women with gestational diabetes mellitus (GDM), but whether stretches of differentially methylated regions (DMRs) can also be identified in adolescent GDM offspring is unknown. Here, we investigate which DNA regions in adolescent offspring are differentially methylated in blood by exposure to diabetes in pregnancy. The secondary aim was to characterize the RNA expression of the identified DMR, which contained the nc886 non-coding RNA.

METHODS

To identify DMRs, we employed the bump hunter method in samples from young (9-16 yr, n = 92) offspring of women with GDM (O-GDM) and control offspring (n = 94). Validation by pyrosequencing was performed in an adult offspring cohort (age 28-33 years) consisting of O-GDM (n = 82), offspring exposed to maternal type 1 diabetes (O-T1D, n = 67) and control offspring (O-BP, n = 57). RNA-expression was measured using RT-qPCR in subcutaneous adipose tissue and skeletal muscle.

RESULTS

One significant DMR represented by 10 CpGs with a bimodal methylation pattern was identified, located in the nc886/VTRNA2-1 non-coding RNA gene. Low methylation status across all CpGs of the nc886 in the young offspring was associated with maternal GDM. While low methylation degree in adult offspring in blood, adipose tissue, and skeletal muscle was not associated with maternal GDM, adipose tissue nc886 expression was increased in O-GDM compared to O-BP, but not in O-T1D. In addition, adipose tissue nc886 expression levels were positively associated with maternal pre-pregnancy BMI (p = 0.006), but not with the offspring's own adiposity.

CONCLUSIONS

Our results highlight that nc886 is a metastable epiallele, whose methylation in young offspring is negatively correlated with maternal obesity and GDM status. The physiological effect of nc886 may be more important in adipose tissue than in skeletal muscle. Further research should aim to investigate how nc886 regulation in adipose tissue by exposure to GDM may contribute to development of metabolic disease.

Association of child weight with attendance at a healthy lifestyle service among women with obesity during pregnancy

Women with obesity during pregnancy are at increased risk of excessive gestational weight gain (GWG) and other maternal and infant adverse outcomes, which all potentially increase childhood obesity. This study explored infant weight outcomes for women with a body mass index (BMI) ≥ 35 kg/m² who were offered an antenatal healthy lifestyle service. A retrospective cohort study, including linking data from two separate health care Trusts, was undertaken. Data were collected from maternity records for women with a BMI ≥ 35 kg/m2 referred to an antenatal healthy lifestyle service from 2009 to 2015. The respective child's weight outcome data was additionally collected from health and National Child Measurement Programme records. Univariate logistic regression determined the odds of childhood overweight, obesity and severe obesity according to attendance at the antenatal healthy lifestyle service, GWG and sociodemographic characteristics. Factors significant (p < 0.05) within the univariate analysis were entered into multiple logistic regression models. Among women with a BMI ≥ 35 kg/m², 30.4% of their children were obese at school entry and 13.3% severely obese. Healthy lifestyle service attendance was not associated with childhood overweight or obesity at any point within the univariate analysis. At school age multiple regression analysis showed the odds of overweight and obesity increased with excessive GWG and the odds of obesity decreased with a parent in a professional occupation, additionally having a mother who smoked in pregnancy increased severe obesity. Women should be supported to optimise their BMI before pregnancy. Additionally, rather than exclusively focusing on changing an individual's behaviour, future interventions should consider external influences such as the woman's family, friends and sociodemographic background.

Close Adherence to a Mediterranean Diet during Pregnancy Decreases Childhood Overweight/Obesity: A Prospective Study

The study of dietary patterns during pregnancy may be of great importance for determining the potential risk of obesity in childhood. We assessed the prospective association between maternal adherence to the Mediterranean diet (MedDiet) during pregnancy and risk of childhood overweight/obesity at 4 years. This prospective analysis involved 272 mother-child pairs from the ECLIPSES study. Maternal diet during pregnancy was assessed using a validated 45-item food-frequency questionnaire and a relative whole-pregnancy MedDiet score (rMedDiet) was calculated. The children's weight and height were measured at the age of 4. Primary outcome was childhood overweight/obesity based on age- and-sex-specific BMI z-score > 85th percentile using the WHO child growth standards. Mean maternal rMedDiet score in pregnancy was 9.8 (±standard deviation 2.3) and 25.7% of the children were overweight/obese. Significant differences in anthropometric measurements (weight, height, and BMI) were found according to sex, with higher scores for boys. After controlling for potential confounders, greater maternal adherence to rMedDiet during pregnancy was associated with a lower risk of childhood overweight/obesity, highest vs. lowest quartile (OR = 0.34, 95% CI: 0.12-0.90; p-trend 0.037). Similar trends regarding this association (per 1-point increase rMedDiet score) were observed after stratification by advanced maternal age, maternal early pregnancy BMI, education, socioeconomic status, smoking, and gestational weight gain. Our findings suggest that closer adherence to the MedDiet during pregnancy may protect against the risk of offspring overweight/obesity at 4 years. Further research is needed to explore whether associations persist across the life course.

App-Supported Lifestyle Interventions in Pregnancy to Manage Gestational Weight Gain and Prevent Gestational Diabetes: Scoping Review

BACKGROUND

Excessive gestational weight gain (GWG) and gestational diabetes mellitus (GDM) are common pregnancy complications that have been shown to be preventable through the use of lifestyle interventions. However, a significant gap exists between research on pregnancy lifestyle interventions and translation into clinical practice. App-supported interventions might aid in overcoming previous implementation barriers. The current status in this emerging research area is unknown.

OBJECTIVE

This scoping review aims to provide a comprehensive overview of planned, ongoing, and completed studies on eHealth and mobile health (mHealth) app-supported lifestyle interventions in pregnancy to manage GWG and prevent GDM. The review assesses the scope of the literature in the field; describes the population, intervention, control, outcomes, and study design (PICOS) characteristics of included studies as well as the findings on GWG and GDM outcomes; and examines app functionalities.

METHODS

The scoping review was conducted according to a preregistered protocol and followed established frameworks. Four electronic databases and 2 clinical trial registers were systematically searched. All randomized and quasi-randomized controlled trials (RCTs) of app-supported lifestyle interventions in pregnancy and related qualitative and quantitative research across the different study phases were considered for inclusion. Eligible studies and reports of studies were included until June 2022. Extracted data were compiled in descriptive analyses and reported in narrative, tabular, and graphical formats.

RESULTS

This review included 97 reports from 43 lifestyle intervention studies. The number of published reports has steadily increased in recent years; of the 97 included reports, 38 (39%) were trial register entries. Of the 39 identified RCTs, 10 efficacy or effectiveness trials and 8 pilot trials had published results on GWG (18/39, 46%); of these 18 trials, 7 (39%) trials observed significant intervention effects on GWG outcomes. Of all 39 RCTs, 5 (13%) efficacy or effectiveness trials reported GDM results, but none observed significant intervention effects on GDM. The RCTs included in the review were heterogeneous in terms of their PICOS characteristics. Most of the RCTs were conducted in high-income countries, included women with overweight or obesity and from all BMI categories, delivered multicomponent interventions, delivered interventions during pregnancy only, and focused on diet and physical activity. The apps used in the studies were mostly mHealth apps that included features for self-monitoring, feedback, goal setting, prompts, and educational content. Self-monitoring was often supported by wearable activity monitors and Bluetooth-connected weight scales.

CONCLUSIONS

Research in this field is nascent, and the effectiveness and implementability of app-supported interventions have yet to be determined. The complexity and heterogeneity of intervention approaches pose challenges in identifying the most beneficial app features and intervention components and call for consistent and comprehensive intervention and outcome reporting.

Randomised controlled trial of preconception lifestyle intervention on maternal and offspring health in people with increased risk of gestational diabetes: study protocol for the BEFORE THE BEGINNING trial

INTRODUCTION

Gestational diabetes mellitus (GDM) is associated with increased risk for type 2 diabetes in the mother and cardiometabolic diseases in the child. The preconception period is an optimal window to adapt the lifestyle for improved outcomes for both mother and child. Our aim is to determine the effect of a lifestyle intervention, initiated before and continued throughout pregnancy, on maternal glucose tolerance and other maternal and infant cardiometabolic outcomes.

METHODS AND ANALYSIS

This ongoing randomised controlled trial has included 167 females aged 18-39 years old at increased risk for GDM who are contemplating pregnancy. The participants were randomly allocated 1:1 to an intervention or control group. The intervention consists of exercise (volume is set by a heart rate-based app and corresponds to ≥ 1 hour of weekly exercise at ≥ 80% of individual heart rate maximum), and time-restricted eating (≤ 10 hours/day window of energy intake). The primary outcome measure is glucose tolerance in gestational week 28. Maternal and offspring outcomes are measured before and during pregnancy, at delivery, and at 6-8 weeks post partum. Primary and secondary continuous outcome measures will be compared between groups based on the 'intention to treat' principle using linear mixed models.

ETHICS AND DISSEMINATION

The Regional Committees for Medical and Health Research Ethics in Norway has approved the study (REK 143756). The anonymised results will be submitted for publication and posted in a publicly accessible database of clinical study results.

TRIAL REGISTRATION NUMBER

Clinical trial gov NCT04585581.

Maternal Pre-Pregnancy BMI, Offspring Adiposity in Late Childhood, and Age of Weaning: A Causal Mediation Analysis

Infant feeding practices have been hypothesized to influence offspring's body mass index (BMI) later in life, and women with overweight or obesity tend to wean their infants earlier than women with healthy BMI. We, therefore, aimed to investigate how much early age of weaning mediated the maternal-offspring adiposity relationship. The study included 4920 mother-child pairs from the Avon Longitudinal Study of Parents and Children birth cohort. G-computation was applied to estimate the natural direct (NDE) and indirect (NIE) effects, via the age of weaning (<3 months, 3 months, >3 months), of maternal pre-pregnancy overweight or obesity on offspring's BMI and fat mass index. The NDE of maternal overweight or obesity on offspring BMI at 17 years old was 2.63 kg/m² (95% CI: 2.27 to 2.99). The NIE via the age of weaning was 0.02 kg/m² (95% CI: 0.00 to 0.04), corresponding to 0.8% of the total effect. Similar results were observed for the offspring's fat mass index. The NDE and NIE were similar to the main analyses when we looked at the relationship stratified by breastfeeding status. Our study found a minimal influence of age of weaning on the pathway between maternal and offspring adiposity, indicating the age of weaning may not be a key mediator.

Optimizing Prepregnancy Cardiovascular Health to Improve Outcomes in Pregnant and Postpartum Individuals and Offspring: A Scientific Statement From the American Heart Association

This scientific statement summarizes the available preclinical, epidemiological, and clinical trial evidence that supports the contributions of prepregnancy (and interpregnancy) cardiovascular health to risk of adverse pregnancy outcomes and cardiovascular disease in birthing individuals and offspring. Unfavorable cardiovascular health, as originally defined by the American Heart Association in 2010 and revised in 2022, is prevalent in reproductive-aged individuals. Significant disparities exist in ideal cardiovascular health by race and ethnicity, socioeconomic status, and geography. Because the biological processes leading to adverse pregnancy outcomes begin before conception, interventions focused only during pregnancy may have limited impact on both the pregnant individual and offspring. Therefore, focused attention on the prepregnancy period as a critical life period for optimization of cardiovascular health is needed. This scientific statement applies a life course and intergenerational framework to measure, modify, and monitor prepregnancy cardiovascular health. All clinicians who interact with pregnancy-capable individuals can emphasize optimization of cardiovascular health beginning early in childhood. Clinical trials are needed to investigate prepregnancy interventions to comprehensively target cardiovascular health. Beyond individual-level interventions, community-level interventions must include and engage key stakeholders (eg, community leaders, birthing individuals, families) and target a broad range of antecedent psychosocial and social determinants. In addition, policy-level changes are needed to dismantle structural racism and to improve equitable and high-quality health care delivery because many reproductive-aged individuals have inadequate, fragmented health care before and after pregnancy and between pregnancies (interpregnancy). Leveraging these opportunities to target cardiovascular health has the potential to improve health across the life course and for subsequent generations.

Gestational weight gain in women with pre-pregnancy overweight or obesity and anthropometry of infants at birth

Objective

To examine the association of gestational weight gain (GWG) among women with pre-pregnancy overweight or obesity with infant weight and BMI z-score at birth.

Methods

This study is a secondary analysis of a randomized controlled trial including data from 208 infants at birth born by mothers with pre-pregnancy BMI between 28 and 45 kg/m² who completed the APPROACH study (randomized to a high-protein low-glycemic index diet or a moderate-protein moderate-glycemic index diet). This analysis pooled the two diet treatment groups together and data were analyzed using a linear mixed model.

Results

Limiting GWG by 1 kg was associated with lower birthweight (-16 g, P = 0.003), BMI z-score (-0.03SD, P = 0.019), weight z-score (-0.03SD, P = 0.004), and infant abdominal circumference (-0.06 cm, P = 0.039). Infants born by mothers whose GWG was ≤9 kg weighed less (122 g, 95% CI: 6-249, P = 0.040), had similar BMI z-score (0.2SD, 95% CI: -0.06 to 0.55, P = 0.120), and lower incidence of emergency cesarean deliveries (11.5% vs. 23.1%, P = 0.044) compared to infants born by mothers whose GWG was >9 kg. When women were classified into GWG quartiles, women in Q1 (GWG range: -7.0 to 3.2 kg) gave birth to smaller infants (3,420 g, P = 0.015) with lower BMI z-score (-0.5SD, P = 0.041) than women in Q2 (3.3-7.1 kg), Q3 (7.2-10.9 kg) and Q4 (11.1-30.2 kg).

Conclusions

Limiting GWG among women with pre-pregnancy overweight or obesity was associated with lower infant weight, BMI z-score, weight z-score, and abdominal circumference at birth. Moreover, GWG below the Institute of Medicine guideline of a maximum of 9 kg was associated with lower birthweight and fewer emergency cesarean deliveries.

Lifestyle Interventions to Improve Pregnancy Outcomes: a Systematic Review and Specified Meta-Analyses

To compare the impact of lifestyle interventions for overweight and obese pregnant women a systematic review and meta-analysis was conducted using pre-registration and audit of the interventions as selection criteria. PubMed, Web of Science and CENTRAL were searched for randomized controlled trials examining diet, exercise, combined interventions or associated behavioral therapy. Trials were selected if they reported one of the primary outcomes (gestational diabetes, hypertensive disorders, perinatal mortality, admission to neonatal intensive care unit). Results were established from the total group and separately from pre-registered or clinically audited studies. Out of 1304 titles, 28 randomized controlled trials were included. Among the primary outcomes only hypertensive disorders were significantly reduced by exercise in the total group: odds ratio 0.52 (95% confidence interval 0.28 to 0.96, four trials, 1324 participants). When behavioral therapy supported combined interventions, maternal weight gain, (Standardized Mean Difference -0.16 kilogram; 95% confidence interval -0.28 to -0.04, four trials, 2132 participants) and neonatal birthweight, (Standardized Mean Difference -0.4 gram; 95% confidence interval -0.62 to -0.18, five trials, 1058 participants), were significantly reduced within the total group and both specified meta-analyses. Higher frequencies of physical activity improved the results. Risk of bias, assessed with the Cochrane Tool, was low to moderate. Elements of behavioral therapy might better prevent adverse effects of maternal obesity when combined with lifestyle interventions. Unfortunately, high heterogeneity due to different intervention and population characteristics was a limiting factor. Future studies should also focus on increased intensities of physical activity.

Why do preconception and pregnancy lifestyle interventions demonstrate limited success in preventing overweight and obesity in children? A scoping review protocol

Adverse family-based lifestyle factors in the preconception period, pregnancy and early-childhood are major risk factors for childhood obesity and there is a growing consensus that early life interventions to prevent overweight and obesity in children are required. However, results from recent systematic reviews of preconception and pregnancy interventions have demonstrated mixed success. Therefore, this protocol presents a study aiming to summarise and evaluate complex preconception and pregnancy intervention components, process evaluation components, and authors' statements, with a view to improving our understanding regarding their success and informing design or adaptation of more effective interventions to prevent childhood obesity. A scoping review will be conducted, using the frameworks of the JBI and Arksey and O'Malley. A two-step approach will be used to identify relevant literature: (1) systematic searches will be conducted in the databases PubMed, Embase and CENTRAL to identify all eligible preconception and pregnancy trials with offspring data; and (2) CLUSTER searches will be conducted to find linked publications to eligible trials (follow-ups, process evaluation publications). Two researchers will independently select studies, chart, and synthesise data. A qualitative thematic analysis will be performed in which statements related to process evaluation components and authors' interpretations will be coded as "reasons". A descriptive analysis will be performed to evaluate intervention complexity using a complex intervention framework (AHRQ series; Medical Research Council guidance). The results of this study, which will be discussed with an expert group as part of a consultation stage, aim to identify gaps and inform the design or adaptation of future preconception and pregnancy interventions and approaches to potentially increase success rates. We expect that our results, which will be submitted for publication in a peer-reviewed journal, will be of interest to researchers, families, and practitioners concerned with good preconception and prenatal care, and healthy child outcomes.

Low-Protein Infant Formula and Obesity Risk

Infant formulas have been designed to mimic human milk for infants who cannot be breastfed. The overall goal is to establish similar functional outcomes to assure optimal growth, development, maturation of the immune system, and programming of the metabolic system. However, after decades of improving infant formula, growth patterns and body composition development are still different in formula-fed infants compared to breastfed infants, which could contribute to an increased risk of obesity among formula-fed infants. It has been hypothesized that the lower protein concentration of breast milk compared to infant formula influences infants’ growth and body composition. Thus, several trials in formula-fed infants with different protein intake levels have been performed to test this hypothesis. In this review, we discuss the current evidence on low-protein infant formula and obesity risk, including future perspectives and implications.

Biogenic Phytochemicals Modulating Obesity: From Molecular Mechanism to Preventive and Therapeutic Approaches

The incidence of obesity and over bodyweight is emerging as a major health concern. Obesity is a complex metabolic disease with multiple pathophysiological clinical conditions as comorbidities are associated with obesity such as diabetes, hypertension, cardiovascular disorders, sleep apnea, osteoarthritis, some cancers, and inflammation-based clinical conditions. In obese individuals, adipocyte cells increased the expression of leptin, angiotensin, adipocytokines, plasminogen activators, and C-reactive protein. Currently, options for treatment and lifestyle behaviors interventions are limited, and keeping a healthy lifestyle is challenging. Various types of phytochemicals have been investigated for antiobesity potential. Here, we discuss pathophysiology and signaling pathways in obesity, epigenetic regulations, regulatory mechanism, functional ingredients in natural antiobesity products, and therapeutic application of phytochemicals in obesity.

Child Anthropometrics and Neurodevelopment at 2 and 3 Years of Age Following an Antenatal Lifestyle Intervention in Routine Care-A Secondary Analysis from the Cluster-Randomised GeliS Trial

Maternal characteristics around pregnancy may influence obesity risk and neurodevelopment in children. To date, the effect of antenatal lifestyle interventions on long-term child development is unclear. The objective was to investigate the potential long-term effects of an antenatal lifestyle intervention programme conducted alongside routine care on child anthropometrics and neurodevelopment up to 3 years of age. Mother-child pairs from the cluster-randomised GeliS trial were followed up to 3 years of age. Data on child anthropometrics in both groups were collected from routine health examinations. Neurodevelopment was assessed via questionnaire. Of the 2286 study participants, 1644 mother-child pairs were included in the analysis. Children from the intervention group were less likely to score below the cut-off in Fine motor (p = 0.002), and more likely to have a score below the cut-off in Problem-solving (p < 0.001) compared to the control group at 3 years of age. Mean weight, height, head circumference, body mass index, and the respective z-scores and percentiles were comparable between the groups at 2 and 3 years of age. We found no evidence that the lifestyle intervention affected offspring development up to 3 years of age. Further innovative intervention approaches are required to improve child health in the long-term.

Maternal mindful eating as a target for improving metabolic outcomes in pregnant women with obesity

BACKGROUND

Maternal diet and eating behaviors have the potential to influence the metabolic milieu in pregnancies complicated by obesity, with implications for the developmental programming of offspring obesity. Emerging evidence suggests that mindfulness during eating may influence metabolic health in non-pregnant populations, but its effects in the context of pregnancy is less well understood. This study explored the individual and combined effects of mindful eating and diet quality on metabolic outcomes among pregnant women with obesity.

METHODS

In 46 pregnant women (body mas index >30 kg/m2) enrolled in the MomEE observational study, mindful eating (Mindful Eating Questionnaire, MEQ) and energy-adjusted dietary inflammatory index (DII, from 7 days of food photography) was assessed at two time points and the mean pregnancy values computed. Rate of gestational weight gain (GWG) and fat mass gain per week were determined from measured weight and body composition using a three-compartment method, respectively, at each assessment. Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) and ghrelin concentrations were determined from fasting blood samples in late gestation (35-37 weeks). Linear regression was used to examine the association of the MEQ and its subscales (where higher values indicate more mindful eating) with metabolic outcomes, adjusting for covariates: maternal age, pregravid body mass index, race, parity, DII. The effects of the MEQ*DII interaction was also tested.

RESULTS

Total MEQ scores were not associated with rate of weight or fat mass gain, although greater distracted eating behavior was associated with greater adiposity gain (weight and fat mass). Mindful eating was inversely associated with insulin resistance, although this was attenuated to non-significance after additional adjustment for GWG. Total MEQ and the external eating subscale was significantly inversely associated with fasted ghrelin, such that less tendency to eat under the influence of external cues was associated with lower ghrelin concentrations. After false discovery rate adjustment for multiple testing, only the association of the total MEQ and external eating subscale with ghrelin levels trended towards significance. The DII was not associated with MEQ scores or outcome variables, nor did it moderate the effect of MEQ on any of the outcomes.

CONCLUSION

This study generates early evidence to suggest that mindful eating holds potential as a tool to improve metabolic health outcomes in pregnant women with obesity, although further research is required on this topic. Prenatal lifestyle interventions should consider including mindfulness during eating to determine its efficacy for reducing adverse pregnancy and offspring health outcomes associated with maternal obesity.

Portable HEPA filter air cleaner use during pregnancy and children's body mass index at two years of age: The UGAAR randomized controlled trial

IMPORTANCE

Gestational exposure to particulate matter (PM) air pollution may increase the risk of childhood obesity, but the impact of reducing air pollution during pregnancy on obesity-related outcomes in childhood has not been examined.

OBJECTIVE

To assess the impact of reducing gestational PM exposure on body mass index (BMI) at two years of age.

METHODS

In this single-blind, parallel group randomized controlled trial in Ulaanbaatar Mongolia, we randomly assigned 540 pregnant women to receive 1-2 portable high efficiency particulate air (HEPA) filter air cleaners or no air cleaners. We measured height and weight when children were a mean age of 23.8 months. Our primary outcome was age- and sex-specific BMI z-score based on the World Health Organization 2007 Growth Charts. Secondary outcomes included age- and sex-specific weight z score, overweight/obesity (defined as BMI z-score > 2.00), and catch-up growth (defined using various cut-offs to identify children with relatively low birth weight for sex and gestational age and relatively high age- and sex-specific weight in childhood). We imputed missing outcome data using multiple imputation with chained equations and our primary analysis was by intention to treat (ITT). We estimated intervention effects on continuous and binary outcomes using linear and logistic regression, respectively.

RESULTS

After excluding known miscarriages, still births, and neonatal deaths our analysis included 480 children (235 control and 245 intervention). The mean (SD) child BMI z score was 0.79 (1.0); 9.8% of children were overweight or obese. The mean BMI z score of children who were randomly assigned to the intervention group was 0.16-units lower (95% CI: -0.35, 0.04) than children in the control group. The intervention was also associated with reductions in overweight/obesity (odds ratio = 0.59; 95% CI: 0.31, 1.12). Catch-up growth occurred less frequently in the intervention group, but effect estimates varied depending on the specific definition of catch-up growth and confidence intervals consistently spanned no effect.

CONCLUSIONS

We found that the use of portable air cleaners during pregnancy was associated with improvements in obesity-related outcomes, although some effect estimates lacked precision. Reducing PM exposure during pregnancy may lead to improvements in cardiometabolic health in childhood.

Theme Trends and Knowledge-Relationship in Lifestyle Research: A Bibliometric Analysis

Healthy living habits (healthy eating, regular physical activity, abstinence from smoking, restrictions on alcohol consumption, and stress management) can help prevent a significant number of diseases. The purpose of this study is to use a bibliometric analysis to analyze the relationships between countries, institutions and authors through lifestyle studies from 2016 to 2020 to find out the latest research trends. This study utilized bibliometric data collected through Scopus including thesis titles, authors, agencies, countries/regions, publication years, and keywords. Data were analyzed using the VOS viewer (Vers. 1.6.13; Leiden University, Leiden, The Netherlands) and the findings were used to visualize similarity mapping techniques. Publication of lifestyle-related research papers has steadily increased between 2016 and 2020. The country/region most actively conducting such research was the United States, also home to the majority of institutions conducting work in the field. PloS ONE published the most lifestyle-related research under the field of Medicine. Identified keywords were related to risk measures, psychosocial factors, prevention, health promotion, and risk factors. Lifestyle research is a promising field of research worldwide and has great potential to improve human health, the environment, and quality of life. The findings are expected to promote future research and give direction to the advancement of the field of research by comprehensively analyzing and summarizing lifestyle research trends.

Antenatal Fetal Size and Obesity in Five-Year-Old Children in a Large Cohort Created by Data Linkage

Background: What is not well understood is the gestational age at which the fetal size deviates from normal for children who develop obesity. Here we test the hypothesis that large-for-gestational age before birth is associated with increased risk for obesity in early childhood. Methods: In this retrospective study, routinely acquired antenatal ultrasound assessments in the first, second, and third trimester were linked to anthropometric measurements at 5.5 years. Results: There were 15,760 individuals, including 678 with obesity, 1955 overweight, and 1254 thin. Compared with children of healthy weight, children who had obesity were shorter in the first trimester [mean difference 0.19 z scores (0.10, 0.28)] and heavier in the second [mean difference z scores 0.15 (0.03, 0.27)] and third trimester [mean difference z scores 0.18 (0.05, 0.32)]. Children in the thin category were lighter compared with children of healthy weight in the third trimester and those in the overweight category were heavier compared with children of healthy weight in the third trimester. All associations were independent of birth weight. Conclusions: The difference in growth trajectories between children who have obesity compared with overweight or thin suggests different underlying mechanisms.