Association of a low chest-to-head circumference ratio with breech or transverse lie: the Japan Environment and Children's Study

OBJECTIVE

We examined whether the chest-to-head circumference ratio at birth was associated with breech presentation and transverse lie. We also described the obstetric management of such pregnancies in the Japan Environment and Children's Study (JECS).

METHODS

We performed a cross-sectional evaluation of data collected between January 2011 and March 2014 in a nationwide prospective birth cohort study, the JECS. We analyzed 83,822 non-anomalous singletons born at 34-41 weeks' gestation to mothers with no history of previous cesareans or uterine surgery. We defined low, normal (reference group), and high chest-to-head circumference ratios as <10th percentile, 10th to 90th percentiles, and >90th percentile, respectively. Logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs) for breech presentation and transverse lie. The timing and mode of delivery of such pregnancies were examined.

RESULTS

Breech presentation was recorded in 2.6% and transverse lie in 0.2%. A low chest-to-head circumference ratio was associated with increased rate of breech presentation (5.2%; adjusted OR 2.36, 95% CI: 2.10-2.65) and transverse lie (0.3%; adjusted OR 2.33, 95% CI: 1.50-3.60), whereas a high ratio was linked to reduced breech presentation (1.1%; adjusted OR 0.51, 95% CI: 0.39-0.66). Subgroup analysis of children delivered by cesarean (n = 7971) showed a similar association, albeit with slightly reduced strength for breech presentation. Eighty-three percent of breech births and 46.3% of transverse lie births occurred at 37-38 weeks' gestation. Cesarean section was performed in 96.8% of breech presentations and 63.4% of transverse-lie ones.

CONCLUSIONS

These findings imply that the fetal chest-to-head circumference ratio may influence presentation at birth.

Comparison of emergency transport for acute alcohol intoxication before and after the coronavirus disease 2019 pandemic: A retrospective observational study

The ongoing coronavirus disease 2019 (COVID-19) pandemic has had a broad effect on social, economic, educational, and political systems. We investigated the effect of COVID-19 on emergency transportation due to acute alcohol intoxication in the Kochi Prefecture in Japan, a region with high alcohol consumption. This retrospective observational study was conducted using the data of 62,138 patients from the Kochi-Iryo-Net database, Kochi Prefecture's emergency medical and wide-area disaster information system. Chi-square tests and multiple logistic regression analyses were performed to examine the association between emergency transportation and alcohol intoxication. This analysis compared the monthly number of transportations during 2019 (as reference) with that throughout 2020 and 2021. Approximately 1.5 % of all emergency transportation cases were related to acute alcohol intoxication. The number of emergency transportation cases due to acute alcohol intoxication declined by 0.5 % in 2020 and 0.7 % in 2021 compared with that in 2019. Moreover, compared with that in 2019, the number of cases of emergency transportation due to acute alcohol intoxication significantly decreased in 2020 (incidence rate ratio: 0.78; 95 % confidence interval: 0.67-0.91) and 2021 (incidence rate ratio: 0.73; 95 % confidence interval: 0.63-0.86). Lifestyle changes due to the COVID-19 pandemic affected the number of emergency transports due to acute alcohol intoxication in 2020 and 2021 (during the COVID-19 pandemic) compared to that in 2019 (before the pandemic).

Prenatal risk factors of indoor environment and incidence of childhood eczema in the Japan Environment and Children's Study

The quality of indoor environment is a risk factor for early childhood eczema and atopic dermatitis; however, its influence during pregnancy on childhood eczema in Japan has not been investigated. In this study, we aimed to determine the indoor environmental factors that are associated with eczema in children up to 3 years of age, using national birth cohort data from the Japan Environment and Children's Study (JECS). Information on indoor environments and eczema symptoms until 3 years of age was collected using self-administered questionnaires to the mothers. A total of 71,883 and 58,639 mother-child pairs at 1.5- and 3-years-old, respectively, were included in the former analyses. To account for prenatal indoor risk factors, 17,568 (1.5-years-old) and 7063 (3-years-old) children without indoor mold and/or ETS exposure were included in the final analysis. A higher mold index, gas heater use, parquet flooring use, and frequent insecticide use showed significantly increased risks for childhood eczema up to 3 years of age. These associations were consistent after stratification analysis among children whose parents did not have a history of allergies. The updated WHO guidelines on indoor air quality should be implemented based on recent findings regarding the effects of prenatal exposure to indoor dampness on health effects of children further in life, including asthma, respiratory effects, eczema, and other immunological effects.

Teenage and young adult pregnancy and depression: findings from the Japan environment and children's study

Teenage pregnancy increases the threat of depression because of its many factors. Pregnancy during young adulthood may also have several risk factors for depression compared to older pregnancies. However, data on depression in young adult pregnancies are lacking. This study investigated the association between teenage and young adult pregnancy and depression. Data from the Japan Environment and Children's study was used as a nationwide multicenter prospective cohort study. A multivariate logistic regression was performed to investigate the association between age groups (14-19, 20-24, 25-29, 30-34, ≥ 35 years) and depression, adjusted for behavioral and sociodemographic characteristics. Depression was assessed using the Kessler Psychological Distress Scale. In total, 96,808 pregnant women responded to the questionnaire. Teenage (14-19 years) and young adult (20-24 years) pregnancy were associated with an increased risk of depression compared to older pregnancy (≥ 35 years) (teenage: OR 4.28, 95% confidence interval, CI [3.24-5.64]; young adult: OR 3.00, 95% CI [2.64-3.41]). After adjusting for covariates, the magnitude of the risk of depression was attenuated. However, teenage and young adult pregnancy remained at a significantly increased risk of depression compared to older pregnancy (teenage: OR 2.38, 95% CI [1.77-3.21]; young adult: OR 2.14, 95% CI [1.87-2.46]). Our findings indicate that teenage and young adults' pregnancy are at an increased risk of depression compared to older pregnancy. These findings suggest prioritizing teenage and young pregnant women for prevention and interventions related to depression.

Clustered Cystic Changes in Long-Term Follow-Up Thin-Section Computed Tomographic Findings in Fibrotic Nonspecific Interstitial Pneumonia

Objectives

The purpose of this study was to retrospectively assess cystic changes in findings on follow-up CT scans of patients with fibrotic nonspecific interstitial pneumonia (NSIP).

Methods

The initial and last high-resolution CT scans of 58 patients with pathologically proven fibrotic NSIP were evaluated retrospectively. The median follow-up periods were 48 months (range, 12-183 months). The pattern, extent, and distribution of abnormal CT findings were compared with findings in the same region on previous and subsequent CT scans with a focus on cystic lesions.

Results

Cystic lesions in a cluster were shown in 16 patients (28%) with fibrotic NSIP on the last CT scans. Focal clustered cysts were found in 5 cases and diffuse clustered cysts were seen in 11 cases. Focal clustered cysts mimicked honeycombing seen in usual interstitial pneumonia (UIP). Diffuse cysts were uniform in size in 7 of the 11 cases. Traction bronchiectasis in a cluster was seen in 3 of the 7 cases. The clustered cystic changes on CT during the course of NSIP mainly consisted of traction bronchiectasis and bronchiolectasis.

Conclusions

Long-standing NSIP did not form honeycombing. The clustered cysts in patients with fibrotic NSIP were mainly remodeling of bronchiectasis.

Health Effects of Electrolyzed Hydrogen Water for the Metabolic Syndrome and Pre-Metabolic Syndrome: A 3-Month Randomized Controlled Trial and Subsequent Analyses

We studied the effect of three months' use of electrolyzed hydrogen water (EHW, Electrolyzed Hydrogen Water conditioner produced by Nihon Trim Co., Ltd.) on metabolic and pre-metabolic syndrome groups. This research was carried out jointly by Susaki City; Nihon Trim Co., Ltd.; and Kochi University as part of a local revitalization project with health as a keyword. A randomized, placebo-controlled, double-blind, parallel-group trial was conducted to evaluate the clinical impact of EHW on participants who suffered from metabolic syndrome or pre-metabolic syndrome. EHW was produced via electrolysis using a commercially available apparatus (Nihon Trim Co., Ltd., Osaka, Japan). During exercise, oxidative stress increases, and active oxygen species increase. In this study, we examined 181 subjects with metabolic syndrome or pre-metabolic syndrome. Among the group that drank EHW for 3 months, those who also engaged in a high level of physical activity showed a significant difference in waist circumference reduction. Although no significant difference was observed, several positive results were found in the participants who engaged in a high level of physical activity. Urinary 8-OHdG, urinary nitrotyrosine, HbA1c, and blood glucose levels increased in the filtered water (FW) group but decreased in the EHW group. High-sensitivity CRP increased less in the EHW group. 8-Isoprostane decreased more in the EHW group. In subgroup analysis, the EHW group showed a significantly greater reduction in waist circumference than the FW group only when controlled for high physical activity. Based on the result, we suggest that, among participants in the study who suffered from metabolic syndrome and pre-metabolic syndrome in which the level of active oxygen species is said to be higher than in healthy subjects, the group that consumed EHW and also engaged in a high level of physical activity experienced a suppressed or reduced increase in active oxygen species.

Association between eating habits during adolescence and gestational diabetes: data from the Japan environment and children's study

Purpose

It is difficult to change pre-pregnancy eating habits, yet establishing healthy eating habits before pregnancy is important for preventing gestational diabetes mellitus (GDM). This study aimed to examine whether the weight-loss behavior of avoiding between-meal and midnight snacking in teenagers is associated with a reduction in the risk of subsequent GDM.

Methods

We used a dataset (jecs-an-20,180,131) from a nationwide, prospective birth cohort study, the Japan Environment and Children's Study (JECS). We included 89,227 (85.7% of the total) mother-infant pairs with live births. Participants in their second or third trimester were asked to report their weight-loss behavior during their teenage years. The prevalence of GDM was investigated. Differences in maternal characteristics were examined using chi-square tests. Crude and adjusted logistic regression models were constructed to assess the associations of various maternal characteristics with the weight-loss behavior of avoiding between-meal and midnight snacking during teenage years.

Results

A total of 2,066 (2.3%) participants had GDM. Weight-loss behavior in teenagers was associated with a decreased risk of GDM. Among participants with normal weight or overweight prior to pregnancy, the adjusted odds ratios were 0.79 (95% confidence interval, 0.70-0.89) and 0.82 (95% confidence interval, 0.69-0.98), respectively.

Conclusions

The results suggest that teenage weight-loss behaviors, such as avoiding between-meal and midnight snacking, are associated with a decreased risk of developing GDM.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01294-2.

Association between maternal cholesterol level during pregnancy and placental weight and birthweight ratio: data from the Japan Environment and Children's Study

BACKGROUND

Placental weight to birthweight ratio (PW/BW ratio), or its inverse, is used as an indicator of placental efficiency. Past studies have shown an association between an abnormal PW/BW ratio and adverse intrauterine environment, however, no previous studies have examined the effect of abnormal lipid levels during pregnancy on PW/BW ratio. We aimed to evaluate the association between maternal cholesterol levels during pregnancy and placental weight to birthweight ratio (PW/BW ratio).

METHODS

This study was a secondary analysis using the data from the Japan Environment and Children's Study (JECS). 81 781 singletons and their mothers were included in the analysis. Maternal serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) levels during pregnancy were obtained from participants. Associations between maternal lipid levels and placental weight and PW/BW ratio were assessed by regression analysis using restricted cubic splines.

RESULTS

Dose-response relationships were observed between maternal lipid level during pregnancy and placental weight and PW/BW ratio. High TC and LDL-C levels were associated with heavy placental weight and high PW/BW ratio, i.e., inappropriately heavy placenta for birthweight. Low HDL-C level was also associated with inappropriately heavy placenta. Low TC and LDL-C levels were associated with low placental weight and low PW/BW ratio, i.e., inappropriately light placenta for birthweight. High HDL-C was not associated with PW/BW ratio. These findings were independent of pre-pregnancy body mass index and gestational weight gain.

CONCLUSIONS

Abnormal lipid levels such as elevated TC and LDL-C, and low HDL-C level, during pregnancy were associated with inappropriately heavy placental weight.

Influence of chest/head circumference ratio at birth on obstetric and neonatal outcomes: The Japan environment and children's study

OBJECTIVES

Some newborns that are not small-for-gestational-age (non-SGA, birthweight ≥10th percentile for a given gestational age) may have pathologic growth restrictions. This study examined the association of adverse obstetric and neonatal outcomes with chest/head circumference ratio at birth in non-SGA and SGA newborns.

METHODS

This study was a cross-sectional evaluation of data from a nationwide prospective birth cohort study, the Japan Environment and Children's Study. We analyzed 93 690 non-anomalous singletons born at 34-41 gestational weeks. We defined low, normal, and high chest/head circumference ratio as <10th percentile, 10th-90th percentile, and >90th percentile, respectively, according to the internally constructed chest/head circumference percentile chart. Modified Poisson regression was used to estimate adjusted prevalence ratios (aPR) for the outcomes studied.

RESULTS

Compared with non-SGA newborns with a normal ratio, those with a low ratio had an increased occurrence of low birthweight (1.75, 1.58-1.94 [aPR, 95% confidence interval]), cesarean delivery (1.34, 1.29-1.38), Apgar score <7 at 5 min (1.57, 1.14-2.17), respiratory complications (1.20, 1.04-1.39), and prolonged hospitalization (1.36, 1.30-1.42). In contrast, the high-ratio group had a lower rate of low birthweight (0.71, 0.59-0.86), cesarean delivery (0.82, 0.77-0.87), and prolonged hospitalization (0.83, 0.78-0.89). In SGA newborns, a low ratio was associated with increased aPRs for low birthweight, cesarean delivery, hypoglycemia, and prolonged hospitalization, whereas a high ratio showed no such association.

CONCLUSIONS

Findings indicate that the chest/head circumference ratio at birth influence obstetric and neonatal outcomes regardless of the birthweight status.

Imaging diagnosis of pneumoconiosis with predominant nodular pattern: HRCT and pathologic findings

The radiological patterns of known pneumoconiosis have been changing in recent years. The basic pathology in pneumoconiosis is the presence of dust macules, mixed dust fibrosis, nodules, diffuse interstitial fibrosis, and progressive massive fibrosis. These pathologic changes can coexist in dust-exposed workers. High resolution CT reflects pathological findings in pneumoconiosis and is useful for the diagnosis. Pneumoconiosis such as silicosis, coal workers' pneumoconiosis, graphite pneumoconiosis, and welder's pneumoconiosis, has predominant nodular HRCT pattern. Diffuse interstitial pulmonary fibrosis is sometimes found in the lungs of this pneumoconiosis. In the early stages of metal lung, such as aluminosis and hard metal lung, centrilobular nodules are predominant findings, and in the advanced stages, reticular opacities are predominant findings. The clinician must understand the spectrum of expected imaging patterns related to known dust exposures and novel exposures. In this article, HRCT and pathologic findings of pneumoconiosis with predominant nodular opacities are shown.

Laparoscopic treatment for multiple huge diospyrobezoars in the stomach

We report a case of a patient with multiple diospyrobezoars, a phytobezoar attributed to persimmons (Diospyros kaki) consumption, in the stomach, who was treated with laparoscopic complete surgical excision. A 76-year-old man with gastric phytobezoars presented to our hospital. Abdominal contrast-enhanced computed tomography revealed three well-defined, oval, nonhomogeneous masses with a mottled appearance in the stomach. Esophagogastroduodenoscopy revealed three large brown solid phytobezoars and gastric ulcers at the gastric angle. The clinical diagnosis was diospyrobezoar, and, due to the huge masses, the patient eventually underwent laparoscopic treatment when the medical and endoscopic approaches were unsuccessful. After gastrotomy in the anterior wall of the stomach, the phytobezoar was mobile inside the stomach, which was opened beside the gastric incision. The three phytobezoars were removed through the wound protector using sponge-holding forceps; the hole in the gastrotomy was closed in the mucosal and seromuscular layers with an intracorporeal suture technique. The weight and size of the phytobezoars were 140 g and 115 × 55 × 50 mm, 70 g and 55 × 45 × 35 mm, and 60 g and 50 × 40 × 35 mm, respectively. The patient was discharged on the 8th postoperative day without any complications. Laparoscopic surgery to extract bezoar is the treatment of choice for this rare entity, because it is a safe and effective approach.

Filter blot method: A simple method for measuring 3-nitrotyrosine in proteins of atmospheric particulate matter

Air pollutants, such as nitrogen dioxide (NO₂), ozone (O₃), and particulate matter (PM), have been epidemiologically reported to contribute to the onset and exacerbation of asthma. We have previously shown that several proteins in atmospheric PM are allergenic in mouse asthma models and that these proteins are nitrated by atmospheric NO₂ and O₃ in chemical reactions. Based on these results, the amount of 3-nitrotyrosine (3-NT) in atmospheric PM could be an air pollution marker integrating NO₂, O₃, and PM. We established a method to measure 3-NT by high-performance liquid chromatography electrochemical detection (HPLC-ECD). Although this method is accurate, it requires a filter treatment process, which is time-consuming and costly for an environmental monitoring tool, in which many samples are measured simultaneously. Therefore, in this study, we investigated a simple immunoblotting method in which atmospheric PM proteins were directly transferred to a polyvinylidene fluoride (PVDF) membrane and measured using an anti-3-NT antibody (the filter blot method). The 3-NT value obtained from this method was significantly correlated (r = 0.809, p < 0.001) with that of the HPLC-ECD method, with a detection power of 0.1 μg/mL for tyrosine nitrated bovine serum albumin equivalents. Multiple regression analysis using the filter blot method showed that the amount of 3-NT in atmospheric PM was significantly associated with the published environmental measurements of O₃ and PM in the region. Therefore, the filter blot method may be useful for the environmental monitoring of 3-NT in atmospheric PM.

Artificial Intelligence in Quantitative Chest Imaging Analysis for Occupational Lung Disease

Occupational lung disease manifests complex radiologic findings which have long been a challenge for computer-assisted diagnosis (CAD). This journey started in the 1970s when texture analysis was developed and applied to diffuse lung disease. Pneumoconiosis appears on radiography as a combination of small opacities, large opacities, and pleural shadows. The International Labor Organization International Classification of Radiograph of Pneumoconioses has been the main tool used to describe pneumoconioses and is an ideal system that can be adapted for CAD using artificial intelligence (AI). AI includes machine learning which utilizes deep learning or an artificial neural network. This in turn includes a convolutional neural network. The tasks of CAD are systematically described as classification, detection, and segmentation of the target lesions. Alex-net, VGG16, and U-Net are among the most common algorithms used in the development of systems for the diagnosis of diffuse lung disease, including occupational lung disease. We describe the long journey in the pursuit of CAD of pneumoconioses including our recent proposal of a new expert system.

[Allergy and immunotoxicology in preventive and clinical medicine from theory to practice: Occupational allergy and isocyanate-induced asthma]

Genetic and environmental factors and their interactions cause diseases and deteriorate health (Genetic and Environmental Interaction). Exposure to environmental factors plays a major role in the deterioration of health in the workplace.Occupational asthma (OA) is a common disorder in the workplace. Approaches to OA are well described and discussed in "Japanese Guideline for Diagnosis and Management of Occupational Allergic Diseases" by the Japanese Society of Occupational and Environmental Allergy. According to the guideline, OA and work-aggravated asthma comprise work-related asthma, and OA can be further divided into two disease entities: sensitizer-induced OA and irritant-induced OA. The guidelines also describe diagnostic and therapeutic strategies for OA. Since a definitive diagnosis of OA requires a comprehensive decision based on a detailed interview on clinical symptoms related to employment status and clinical tests, including inhalation tests of suspected substances as needed, the possibility of OA should be considered as the first step toward diagnosis of the patient. Otherwise, OA may not be diagnosed. Therapeutic strategies include exposure avoidance, environmental arrangements in the workplace, utilization of social resources for workers, and conventional pharmacotherapy for asthma.Artificially synthesized small compounds are used in various industries and can cause allergies. For example, isocyanates are small compounds in the -NCO group, which have been toxicologically studied. It was later shown that isocyanate could cause various nontoxic adverse health effects, including allergic reactions. Since small agents with low molecular weights bind to proteins, detecting their specific immunoglobulin E (IgE) antibodies targeting small compounds is generally difficult. In contrast, isocyanate-specific IgE antibodies are detectable in individuals with isocyanate allergies.Suspecting OA is essential in cases exposed to newly synthesized compounds, or to those that are already known but applied to new uses, which can be better understood and predicted by studying the health effects of isocyanates.Academic interest in various issues related to allergies, immunology, and toxicology in the workplace includes clinical medicine, epidemiology, and epigenetics related to environmental exposure. Further advanced research in these areas is necessary and promising.

Maternal protein intake in early pregnancy and child development at age 3 years

BACKGROUND

The current study aimed to assess the association between low maternal protein intake during pregnancy and child developmental delay at age 3 years.

METHODS

This research used data obtained from the Japan Environment and Children's Study. In total, we analyzed 77,237 mother-child pairs. Dietary intake was assessed using the Food Frequency Questionnaire. Developmental outcomes at age 3 years were evaluated with the Japanese version of the Ages and Stages Questionnaire, Third Edition. A multivariate logistic regression analysis was performed to assess the association between maternal protein intake during pregnancy and child development delays at age 3 years.

RESULTS

Based on the protein-to-total energy intake ratio during early pregnancy, the participants were categorized into three groups: <9.39% (>2 standard deviation below the mean), the severely low protein (SLP) group; 9.39-<13%, the low protein group; and ≥13%, the normal protein group. After adjusting for potential confounding factors, SLP intake was found to be significantly correlated with a higher risk of developmental delay according to the communication, fine motor and problem-solving skill domains.

CONCLUSIONS

SLP intake caused by inadequate diet during early pregnancy was associated with a higher risk of child developmental delay at age 3 years.

IMPACT

Animal studies have shown that maternal protein restriction during pregnancy and lactation causes abnormal brain development among offspring. Birth cohort studies to date have not assessed the effects of maternal low protein exposure during pregnancy on child development. Severely low protein intake during early pregnancy was associated with a higher risk of child developmental delay at age 3 years. Since nutritional imbalance in early pregnancy affects not only fetal growth but also postnatal neurodevelopment, nutritional management before pregnancy is considered important.

Impact of school closures on pediatric ambulance transport in Japan

BACKGROUND

After the coronavirus disease (COVID-19) pandemic, nationwide school closures were implemented in many countries. This study aimed to determine the impact of the school closures on pediatric ambulance transport, comparing the situation before and after the COVID-19 pandemic.

METHODS

This retrospective observational study was conducted using data from the Kochi-Iryo.net database. In Kochi prefecture, schools were closed from March 6 to May 24, 2020. Pediatric emergency transport during the school closure period in 2020 was compared with that in the same period in 2019 (before the COVID-19 pandemic) and in 2021 (when schools were not closed). Statistical analysis comprised χ² tests with Bonferroni adjustments for multiple testing. To adjust for patient backgrounds, we also performed multiple logistic regression analyses for numbers of pediatric ambulance transports.

RESULTS

The rate of pediatric ambulance transports was significantly lower (p = 0.008) in 2020 (276; 3.97%) than in 2019 (391; 4.87%), but there was no significant difference (p = 0.360) between 2019 (391; 4.87%) and 2021 (352; 4.56%). Multivariable analysis revealed similar trends (2019 vs. 2020: OR 0.86, 95% CI 0.73-1.00; 2019 vs. 2021: OR 0.96, 95% CI 0.82-1.11). Regarding the characteristics of pediatric ambulance transport journeys, there were no significant differences in 2019, 2020, and 2021 in terms of sex, severity, locations of ambulance stations, and disease classification.

CONCLUSIONS

There was a decrease in pediatric ambulance transportation due to the public health interventions for COVID-19, including school closures. However, this decrease was not solely due to school closures.

Prevalence of infectious diseases in preterm infants: a 2-year follow-up from the Japan Environment and Children's Study

Evidence regarding the long-term risk of infections in preterm infants is lacking. In this study, we examined whether preterm infants developed various common childhood infections more frequently than full-term infants by the age of 2 years by analyzing data from a questionnaire completed by 67,282 mother-toddler pairs in a nationwide birth cohort study. Of the target population, 2885 (4.3%) were born prematurely. After covariate adjustment for maternal and children factors, lower respiratory tract infections appeared more frequent in preterm than in full-term infants at both 1 and 2 years (adjusted odds ratio [aOR] 1.21, 95% confidence interval [CI] 1.05-1.41, and aOR 1.27, 95% CI 1.11-1.46, respectively). However, there was no significant difference in the frequencies of lower respiratory tract infection between preterm and full-term infants after Palivizumab administration. The risk of other common infections, such as in the upper respiratory tract infection, otitis media, urinary tract infection, gastroenteritis, herpangina, hand-foot-and-mouth disease, chickenpox, influenza virus, and adenovirus infections, was not higher in preterm than in full-term infants after covariates adjustment for maternal and children factors. These findings suggest Palivizumab prophylaxis could reduce the frequencies of lower respiratory tract infection in preterm to the same level as in full-term infants.

Maternal hemoglobin levels and neonatal outcomes: the Japan Environment and Children's Study

BACKGROUND

Low birth weight (LBW), small for gestational age (SGA), and preterm birth (PTB) are important neonatal outcomes that may affect infant morbidity and mortality. The aim of this study is to investigate associations between maternal hemoglobin (Hb) concentrations and pregnancy outcomes of LBW, SGA, and PTB.

METHODS

This was a prospective birth cohort study using data of the Japan Environment and Children's Study. Participants were divided into five groups according to maternal Hb (g/dL) in the first and second trimesters: group 1, Hb < 9; group 2, 9 ≤ Hb < 11.0; group 3, 11.0 ≤ Hb < 13.0; group 4, 13.0 < Hb < 14.0; and group 5, 14.0 ≤ Hb. We examined the relationships between LBW, PTB, SGA, and maternal Hb in the first and second trimesters.

RESULTS

Excluding 29,673, a total of 74,392 newborns (first trimester: n = 39,084, second trimester: n = 35,308) were included. We obtained adjusted odds ratios (aORs) (95% confidence intervals (CIs)) using multivariate analysis; compared with group 3 in the first trimesters, women in group 1 were at increased risk of PTB (aOR, 3.20; 95% CI, 1.69-6.09), LBW (aOR, 2.21; 95% CI, 1.19-4.09). In the second trimester, multivariate analysis revealed that, compared with group 3 in the second trimester, women in group 1 were at increased risk of PTB (aOR, 2.30; 95% CI, 1.19-4.42) and women in group 5 were at increased risk of LBW (aOR, 1.87; 95% CI, 1.24-2.81) and PTB (aOR, 1.73; 95% CI, 1.06-2.83).

CONCLUSIONS

Elevated maternal Hb in the second trimester was associated with risks of PTB and LBW.

Factor structure of the Parenting Stress Index-Short Form used in the Japan Environment and Children's Study

The Parenting Stress Index-Short Form (PSI-SF) has been widely employed to assess parenting stress in a number of research and clinical trials. To date, no parenting stress studies in Japan have examined the factor structure, validity, and reliability of the PSI-SF. Therefore, this study aimed to evaluate the psychometric properties of this 19-item version as administered in a national cohort study, the Japan Environment and Children's Study, to two sample groups of mothers, those with a 1.5-year-old child and those with a 2.5-year-old child (n = 79,282 and 75,831, respectively). We performed exploratory factor analysis to re-examine the appropriate factor structure, confirmatory factor analysis to evaluate goodness of fit, and calculated Cronbach's α and Pearson's r coefficients to evaluate internal consistency and reproducibility over time, respectively. The results highlighted that a three-factor structure fit the instrument better than a two-factor structure, yielding better scores for the model fit indices and the α and r coefficients. In addition, the third factor identified in this study was strongly associated with having a relationship with and help from the husband. The findings suggest the importance of using a parenting stress scale with various factors to evaluate mothers' parenting stress.

Knowledge, attitude, perception, and factors associated with the risk perception of COVID-19 among nursing college students in Japanese universities: A cross-sectional study

Background and Aim

The spread of coronavirus disease 2019 (COVID-19) in the world has brought different attitudes and perceptions among social strata. Nursing students being future first-line healthcare workers are more at risk of being infected and exposed to various stressors from shared information. The objectives of this study were to evaluate the knowledge, attitude, and perception of COVID-19 among nursing students and to estimate predictors of their risk perception.

Methods

We conducted an online survey among undergraduate nursing students at three selected Japanese Universities. Data on knowledge, attitude, and perception toward COVID-19 were collected using a structured questionnaire. We performed multiple logistic regression analyses to identify factors associated with the risk perception toward COVID-19 infection.

Results

Of the 414 nursing students who participated in the study, 368 (90.4%) reported that the media including radio, television, internet, and/or social media were the main source of knowledge. Fever (96.1%) and dry cough (89.6%) were reported as the main symptoms. Regarding the attitude toward the treatment and preventive measures, almost 92.8% of participants recommended the use of vaccines. Being female appeared to be three times associated with the fear of getting infected (adjusted odds ratio [aOR]:3.03; 95% confidence interval [CI]: 1.21-7.58). Students who took part in extracurricular activities reported that they feared being infected with COVID-19 (aOR:2.62; 95% CI:1.33-5.16). Other factors did not show an association.

Conclusion

Knowledge and attitude of nursing students toward COVID-19 were accurate for the majority of them, with the main source of information being the media. Practicing extracurricular activities and being female were associated with the fear of the disease. Efficient and controlled communication is needed during widespread disease outbreaks.

Inter-observer agreement and accuracy in classifying radiographs for pneumoconiosis among Asian physicians taking AIR Pneumo certification examination

This study examined inter-observer agreement and diagnostic accuracy in classifying radiographs for pneumoconiosis among Asian physicians taking the AIR Pneumo examination. We compared agreement and diagnostic accuracy for parenchymal and pleural lesions across residing countries, specialty training, and work experience using data on 93 physicians. Physicians demonstrated fair to good agreement with kappa values 0.30 (95% CI: 0.20-0.40), 0.29 (95% CI: 0.23-0.36), 0.59 (95% CI: 0.52-0.67), and 0.65 (95% CI: 0.55-0.74) in classifying pleural plaques, small opacity shapes, small opacity profusion, and large opacities, respectively. Kappa values among Asian countries ranging from 0.25 to 0.55 (pleural plaques), 0.47 to 0.73 (small opacity profusion), and 0.55 to 0.69 (large opacity size). The median Youden's J index (interquartile range) for classifying pleural plaque, small opacity, and large opacity was 61.1 (25.5), 76.8 (29.3), and 88.9 (23.3), respectively. Radiologists and recent graduates showed superior performance than other groups regarding agreement and accuracy in classifying all types of lesions. In conclusion, Asian physicians taking the AIR Pneumo examination were better at classifying parenchymal lesions than pleural plaques using the ILO classification. The degree of agreement and accuracy was different among countries and was associated with background specialty training.

Perceptual and objective physical quality of chest images: a comparison between digital radiographic chest images processed for cancer screening and pneumoconiosis screening in Japan

This study (1) evaluated the perceptual and objective physical quality of digital radiographic chest images processed for different purposes (routine hospital use, lung cancer screening, and pneumoconiosis screening), and (2) quantified objectively the quality of chest images visually graded by the Japan National Federation of Industrial Health Organization (ZENEIREN). Four observers rated the images using a visual grading score (VGS) according to ZENEIREN's quality criteria. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were measured. Between groups, differences were assessed using ANOVA (followed by Bonferroni multiple comparisons) or unpaired t-test. The Pearson's correlation coefficients were calculated for the correlation between perceptual quality and objective physical image quality. The image quality perceived by the observers and the SNR measurements were highest for the images generated using parameters recommended for lung cancer screening. The images processed for pneumoconiosis screening were rated poorest by the observers and showed the lowest objective physical quality measurements. The chest images rated high quality by ZENEIREN generally showed a higher objective physical image quality. The SNR correlated well with VGS, but CNR did not. Highly significant differences between the processing parameters indicate that image processing strongly influences the perceptual quality of digital radiographic chest images.

The association between early formula and reduced risk of cow’s milk allergy during the first three year of life: a Japanese cohort study

Background

Our recent observational study showed that regular consumption of cow’s milk (CM) formula during early infancy (3–6 months old) was associated with a reduced risk of CM allergy (CMA) at 12 months old. However, the long-term association is unclear. The present study was aimed to examine how long this inverse association persists after 12 months old.

Methods

This study used the dataset of an ongoing nationwide prospective cohort, the Japan Environment and Children’s Study, in which participants were registered between January 2011 and March 2014. We analyzed 65,568 children followed-up until 36 months old. The exposure factors were the consumption statuses of formula milk from 0–3, 3–6, and 6–12 months old. The primary outcome was the prevalence of CMA at 6, 12, 18, 24 and 36 months old. CMA was defined as an allergic reaction and sensitization to CM protein in an individual with no or limited intake of this protein at the evaluation time, combined with physician-diagnosed food allergy. Multivariable regression models were used to estimate the association between the periods of formula consumption and the prevalence of CMA.

Results

The prevalence of CMA increased with a peak of 1.51% at 18 months old and then declined to 0.79% at 36 months old. Formula milk from 3–6 months old was associated with a reduced risk of CMA throughout the first 3 years of life, although the extent of the reduction was mitigated with age (adjusted relative risk: [95% confidence interval]: 0.19 [0.10–0.34] at 12 months old, 0.23 [0.16–0.33] at 18 months old, 0.41 [0.26–0.64] at 24 months old, and 0.47 [0.26–0.80] at 36 months old). The association between early formula and CMA were observed in both children with and without eczema, but more prominent and long-lasting in the former than the latter.

Conclusions

Regular exposure to CM protein during infancy was associated with a reduced prevalence of CMA during early childhood. At present, however, this observational study does not necessarily encourage formula feeding, and randomized controlled trials are warranted to confirm the findings and their significance.

Gestational weight gain mediates the effects of energy intake on birth weight among singleton pregnancies in the Japan Environment and Children's Study

Background

Extra energy intake is commonly recommended for pregnant women to support fetal growth. However, relevant data regarding variations in energy intake and expenditure, body mass index and gestational weight gain (GWG) are frequently not considered. This study aimed to investigate how energy intake during pregnancy and gestational weight gain (GWG) are associated with birth weight.

Methods

Early pregnant women were recruited into a Japanese nationwide prospective birth cohort study between 2011 and 2014. We analysed data of 89,817 mother-child pairs of live-born non-anomalous singletons after excluding births before 28 weeks or after 42 weeks. Energy intake during pregnancy was estimated from self-administered food frequency questionnaires (FFQ) and was stratified into low, medium, and high. Participants completed the FFQ in mid-pregnancy (mean 27.9 weeks) by recalling food consumption at the beginning of pregnancy. Effects of energy intake on birth weight and mediation by GWG were estimated using the Karlson–Holm–Breen method; the method separates the impact of confounding in the comparison of conditional and unconditional parameter estimates in nonlinear probability models. Relative risks and risk differences for abnormal birth size were calculated.

Results

Mean daily energy intake, GWG, and birth weight were 1682.1 (533.6) kcal, 10.3 (4.0) kg, and 3032.3 (401.4) g, respectively. 6767 and 9010 women had small-for-gestational-age and large-for-gestational-age infants, respectively. Relative to low energy intake, moderate and high intakes increased adjusted birth weights by 13 g and 24 g, respectively: 58 and 69% of these effects, respectively, were mediated by GWG. Compared with the moderate energy intake group, the low energy intake group had seven more women per 1000 women with a small-for-gestational-age birth, whereas the high energy intake group had eight more women per 1000 women with a large-for-gestational-age birth.

Conclusion

GWG mediates the effect of energy intake on birth weight. All pregnant women should be given adequate nutritional guidance for optimal GWG and fetal growth.

Preconception vitamin D intake and obstetric outcomes in women using assisted reproductive technology: the Japan Environment and Children’s Study

Background

In reproductive medicine, vitamin D (VitD) is of particular interest because its deficiency has been linked to various infertility issues. Thus, preconception care, including appropriate VitD supplementation, is essential, especially in women using assisted reproductive technology (ART). Despite the therapeutic benefits of VitD, adverse events due to a high daily intake may influence obstetric outcomes. However, the effects of either low or high preconception VitD intake on obstetric outcomes, including the outcomes in women who used ART, remain unclear. Therefore, the aim of this study was to examine the association between pre-pregnancy daily VitD intake and obstetric outcomes in Japanese women, including those who conceived through ART.

Methods

Data were obtained from the Japan Environment and Children’s study database comprising 92,571 women recruited between January 2011 and March 2014 in Japan. Participants were categorized into five quintiles according to pre-pregnancy VitD intake (Q1 and Q5 had the lowest and highest VitD intake, respectively) and stratified according to the use of ART. Multiple logistic regression was performed to identify the effects of pre-pregnancy VitD intake on preterm birth (PTB), low-birth weight infant (LBW), and small for gestational age (SGA).

Results

Using Q3 (middle VitD intake) as a reference, our analysis revealed that Q5 (highest VitD intake) showed an increased risk of LBW < 1500 g (adjusted odds ratio [aOR]: 1.09, 95% confidence interval [CI]: 1.00–1.18) and SGA (aOR: 1.26, 95% CI: 1.14–1.39) among women who conceived without ART. Among women who conceived with ART, we found that Q5 (highest VitD intake) showed an increased risk of PTB at < 37 weeks (aOR: 2.05, 95% CI: 1.27–3.31).

Conclusion

The present study revealed that higher VitD intake before pregnancy may affect perinatal outcomes, particularly in women using ART. Our findings may facilitate personalized preconceptional counseling regarding VitD intake based on the method of conception, especially among women using ART.

Effects of maternal exposure to lead on secondary sex ratio in Japan: The Japan Environment and Children's Study

A decline in the proportion of male births (secondary sex ratio, SSR) has been seen in several countries including Japan in recent years. Although previous studies have reported that the SSR is affected by exposure to chemical substances such as dioxins and polychlorinated biphenyls, as well as heavy metals such as methylmercury, the effects of lead exposure on the SSR have been little studied. The aim of this study was to determine the association between maternal lead exposure and SSR. In a large-scale nationwide birth cohort study, maternal blood lead level (BLL) was determined using whole blood from the second or third trimester of pregnancy. The association between SSR and maternal BLL was estimated using multivariable logistic models. Binomial distribution was applied to examine the differences in SSR by dividing the participants into five groups based on BLL. The primary outcome was SSR, and the child sex was obtained from the medical record transcripts. Of 104,062 fetal records, 85,171 were examined for analysis. The median maternal BLL was 5.85 ng/g (5th-95th percentile 3.45-10.6 ng/g). The overall proportion of males among participating infants was 0.512. In logistic regression models adjusted for covariates, the analysis revealed an increased odds ratio for SSR with higher blood lead concentrations [Group 2: adjusted OR 1.082, 95% confidence interval 1.037 to 1.129, Group 3: 1.122, 1.074 to 1.171, Group 4: 1.214, 1.163 to 1.268, Group 5: 1.279, 1.224 to 1.336]. Compared to the general birth probability in Japan, the group with low BLL had a lower SSR and the group with high BLL had a higher SSR. Higher maternal lead exposures during pregnancy were associated with increased SSR. Further investigations including assessment of paternal lead exposure are necessary to understand the association between lead exposure and SSR.

Neurological development in 36‐month‐old children conceived via assisted reproductive technology: The Japan Environment and Children's Study

Purpose

This study aimed to investigate neurodevelopment in children conceived via in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) with several types of embryo transfers.

Methods

We analyzed data for 77 928 children and their mothers included in a Japanese birth cohort study. Among the included children, 4071 were conceived via IVF, while 1542 were conceived via ICSI. Neurodevelopmental delay at the age of 3 years was assessed using the Japanese version of the Ages and Stages Questionnaires, 3rd edition.

Results

In the crude model, the odds ratios for developmental delay in 1–4 domains were higher among children conceived via IVF, ICSI, and non‐ART (ovulatory induction or intrauterine insemination) than in spontaneously conceived children. After adjusting for parental background factors and the child's sex, there were no differences in the risk of developmental delay when comparing singletons conceived by IVF, ICSI, or non‐ART and those conceived spontaneously. Higher odds ratios for developmental delay in one domain were observed in singleton girls conceived via IVF when compared with those who were spontaneously conceived.

Conclusion

Most cases of developmental delay may be associated with multiple pregnancies and factors related to infertility, such as parental age, irrespective of the use of ART.

Association of physical activity and sleep habits during pregnancy with autistic spectrum disorder in 3-year-old infants

Background:

We hypothesized that maternal lifestyle factors, such as physical activity and sleep habits, may be associated with autism spectrum disorder (ASD) in infants. This study aimed to investigate the association between maternal physical activity and sleep before and during pregnancy with infant ASD diagnosed by the age of 3 years.

Methods:

We used the data from the Japan Environment and Children’s Study between 2011 and 2014. The study included 103,060 pregnant women, among which, 69,969 women were analyzed. Participants were asked about their physical activity and sleep before and during pregnancy using questionnaires during pregnancy. Maternal physical activity was estimated using the international physical activity questionnaire. Based on the levels of physical activity before or during pregnancy, the participants were divided into five groups. Maternal sleep was analyzed based on sleep duration and bedtime. The outcome was diagnosis of ASD in 3-year-old infants.

Results:

In mothers with higher physical activity levels during pregnancy, the risk ratios (RR) for ASD in their 3-year-old infants were lower (RR = 0.61, 95% confidence interval (CI) = 0.42–0.90). In contrast, too short (<6 h) and too long (>10 h) sleep durations during pregnancy were associated with higher risk ratios for ASD than 7–8 h sleep duration (too short: RR = 1.87, 95% CI = 1.21–2.90; too long: RR = 1.56, 95% CI = 1.00–2.48). These associations were not observed before pregnancy.

Conclusion:

Maternal physical activity and sleep duration during pregnancy may be associated with ASD in infants.

Children with autism spectrum disorder (ASD) have difficulties with communication and can have problematic behavior. It is unclear whether lifestyle habits before and during pregnancy influence the chances of having a child with ASD. We investigated whether maternal physical activity and particular sleep habits before and during pregnancy increased the likelihood of 3-year-old infants having ASD. Mothers completed questionnaires asking about their physical activity, sleep habits, and any diagnosis of ASD in their child. The children of mothers with high levels of physical activity during pregnancy were less likely to have ASD. The children of mothers who had slept for less than 6 h or longer than 10 h a night were more likely to have ASD. Thus, improving sleep and increasing exercise during pregnancy might reduce the risk of ASD in their children.

Nakahara, Michikawa et al determined the physical activity and sleep habits of women before and during pregnancy and compared these with diagnoses of autism spectrum disorder in their offspring. Abnormal sleep and reduced physical activity during pregnancy were associated with a diagnosis of autism spectrum disorder.

Dose-response relationships between maternal urinary cotinine and placental weight and ratio of placental weight to birth weight: The Japan Environment and Children's Study

INTRODUCTION

Studies on the relationship between maternal self-reported smoking status and placental weight report inconsistent results. This study examined the relationships between maternal urinary cotinine concentration and placental weight and the ratio of placental weight to birth weight (PW/BW ratio). The study also examined the relationship between maternal smoking status, as determined by cotinine concentration, with placental weight and with PW/BW ratio, stratified by sex of offspring.

METHODS

Our analysis used information of 91,049 mother-child pairs enrolled in the Japan Environment and Children's Study. Maternal urinary cotinine concentration was quantified (during the second or third trimester) with high-performance liquid chromatography-tandem mass spectrometry. Using restricted cubic splines, placental weight and PW/BW ratio were plotted against natural log-transformed cotinine concentration. Taking cotinine levels of <0.17 ng/mL, 0.17 to <21.5 ng/mL (natural log-transformed values, -1.77 to 3.07), and ≥21.5 ng/mL as indicative of non-smokers, passive smokers, and active smokers, respectively, the relationships between maternal smoking status and placental weight and PW/BW ratio were examined, adjusting for confounders.

RESULTS

Placental weight and PW/BW ratio increased with increasing cotinine concentration. After cotinine reached a certain concentration, the placental weight decreased in male offspring whereas it plateaued in female offspring. Compared with not smoking, active smoking during pregnancy significantly increased placental weight and PW/BW ratio.

CONCLUSION

Placental weight responded as an inverted U-shape whereas the PW/BW ratio followed a J-shape with increasing maternal urinary cotinine concentration measured during pregnancy, suggesting exposure to tobacco smoke induces a disproportionate reduction in fetal growth. The effect of tobacco smoke on placental growth varied by sex of offspring.

Lack of catch-up in weight gain may intermediate between pregnancies with hyperemesis gravidarum and reduced fetal growth: the Japan Environment and Children’s Study

Background

Women with nausea and vomiting of pregnancy (NVP) have higher birth weight infants, while those with hyperemesis gravidarum, a severe manifestation of NVP, have lower birth weight infants. We aimed to investigate the associations between maternal weight loss (a consequence of hyperemesis gravidarum), NVP, and infant birth weight.

Methods

This study was a secondary analysis of a nationwide birth cohort in Japan. Singleton pregnancies delivered at 28–41 weeks of gestation were included in the analysis. Women were categorized based on their weight change in the 1^st trimester (as a proportion to their pre-pregnancy weight: >  + 3%, > 0 to + 3%, > -3 to 0%, > -5 to -3%, ≤ -5%) and severity of NVP (no nausea, only nausea, vomiting but able to eat, vomiting and unable to eat). The effects of weight change and severity of NVP on infant birth weight and small for gestational age (SGA) were assessed using regression models. We further examined how these effects could be modified by maternal weight gain up to the 2^nd trimester.

Results

Among 91,313 women, 5,196 (5.7%) lost ≥ 5% of their pre-pregnancy weight and 9,983 (10.9%) experienced vomiting and were unable to eat in the 1^st trimester. Women with weight loss ≥ 5% in the 1^st trimester had infants 66 (95% CI: 53, 78) g lighter and higher odds of SGA (aOR: 1.29; 95% CI: 1.14, 1.47) than women who gained > 3% during the same period. However, when adjusting for weight gain up to the 2^nd trimester, women with weight loss ≥ 5% in the 1^st trimester had infants 150 (95% CI: 135, 165) g heavier and lower odds of SGA (aOR: 0.39; 95% CI: 0.33, 0.46) than those who gained > 3% during the same period. In contrast, women with more severe NVP tended to have infants with larger birth weight and lower odds of SGA compared to women without NVP. These trends were strengthened when adjusting for weight gain up to the 2^nd trimester.

Conclusions

Our study suggests the possibility that reduced fetal growth in pregnancies with hyperemesis gravidarum may be caused by the lack of catch-up in gestational weight gain up to the 2^nd trimester.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04542-0.

Change in cholesterol level during pregnancy and risk of postpartum depressive symptoms: the Japan Environment and Children's Study (JECS)

OBJECTIVE

Women with postpartum depressive symptoms (PDS) are at higher risk of postpartum depression (PPD) and require further assessment. Emerging evidence indicates a relationship between the total cholesterol (TC) level of blood and PPD but the results are inconsistent. In this study, we investigated the possible association of change in serum TC levels during pregnancy with the risk of PDS in a Japanese population.

METHODS

We analyzed complete data on questionnaire responses and serum lipid profiles of pregnant women from 12 datasets obtained from the Japan Environment and Children's Study (n = 61,585 to n = 72,406; 103,063 pregnancies in total). TC was measured at 3 time points-during early pregnancy, during mid-late pregnancy, and after delivery-and we calculated changes in TC in 3 ways: by subtracting early pregnancy from mid-late pregnancy, subtracting mid-late pregnancy from delivery, and subtracting early pregnancy from delivery. These 6 factors were used as predictors to estimate the risk of PDS at 1 and 6 months after delivery.

RESULTS

In multivariable logistic regression analysis, point serum cholesterol level did not predict PDS at any time point except for during mid-late pregnancy in the second quintile, indicating an increased risk at 6 months. As for change in TC levels, subtracting mid-late pregnancy from delivery and early pregnancy from delivery showed significant risk reduction for PDS at 1 month. A significant risk reduction was also found for subtracting early pregnancy from mid-late pregnancy and early pregnancy from delivery at 6 months.

CONCLUSIONS

Increased cholesterol level during pregnancy is associated with reduced risk of PDS.

Association between nausea and vomiting of pregnancy and postpartum depression: the Japan Environment and Children's Study

OBJECTIVE

Postpartum depression (PPD) is a global emotional distress that affects women and their offspring regardless of their culture. The association between nausea and vomiting of pregnancy (NVP) and PPD has been widely described only for the severe form of NVP. We aimed to assess the relationship between PPD and NVP with regards to its severity.

METHODS

Data from the Japan Environment and Children's Study (JECS), a birth cohort study, were analyzed. PPD was assessed using the Edinburgh Postnatal Depression Scale (EPDS). Multiple logistic regression models were performed to assess the association between NVP and PPD.

RESULTS

Out of the 80,396 women included in the study 14% had PPD. Among them 4,640 (42.1%) had mild NVP; 3,295 (29.9%) had moderate NVP whereas 1,481 (13.4%) had severe NVP. All forms of NVP were associated with PPD and the association gradually increased with the severity of NVP symptoms with odd ratio (OR): 1.26; 95% confidence interval (CI): 1.18-1.35 for mild, OR: 1.28; 95% CI: 1.19-1.38 for moderate and OR: 1.54; 95% CI: 1.42-1.68 for severe NVP.

CONCLUSION

Japanese women with NVP were more susceptible to develop PPD and the more severe the NVP symptoms were, the greater the risk of PPD. Thus, close monitoring of NVP-affected women is recommended.

Breastfeeding and risk of febrile seizures in the first 3 years of life: The Japan Environment and Children's Study

OBJECTIVE

Our study was conducted to examine the association between breastfeeding and febrile seizures (FS) in the first 3 years of life.

METHODS

We analyzed the dataset of the Japan Environment and Children's Study (JECS), which is a birth cohort study undertaken to elucidate the influence of environmental factors on children's health during the fetal period and early childhood. Information on feeding duration and feeding pattern, as well as information on febrile seizures, were obtained from questionnaires sent to mothers/caregivers. We categorized a child as having experienced FS if the child was reported as having been diagnosed with FS in the first 3 years. Modified Poisson regression with a robust error variance was used to estimate the effect of duration of breastfeeding and the risk of FS.

RESULTS

Of the 84,321 children included in the analysis, 6264 (7.4%) were reported to have experienced FS at least once in the first 3 years of life. Multivariate analyses showed that the risk of FS during the first 3 years of life tended to decrease as the duration of breastfeeding increased. Male sex and frequent fever episodes were also associated with an increased risk of FS.

CONCLUSIONS

Continued breastfeeding until 2 years of age, the most susceptible age for FS, had a small but protective effect on FS.

Exogenous oxytocin used to induce labor has no long-term adverse effect on maternal-infant bonding: Findings from the Japan Environment and Children's Study

BACKGROUND

This study investigated the association between exogenous oxytocin use for labor induction and adverse maternal-infant bonding (MIB).

METHODS

Data on 19 700 mother-infant pairs were collected, in which the infants were live-birth singletons, born in cephalic position and at >37 weeks of gestation; the drug used to induce labor was noted. Between 2011 and 2014, Japanese pregnant women were enrolled in a nationwide prospective birth cohort study, the Japan Environment and Children's Study. The Japanese version of the Mother-to-infant Bonding Scale (MIBS-J) was administered and demographic information was collected through medical record transcripts. MIBS-J scores were obtained at one month, six months, and one year after delivery. We estimated the risk of adverse MIB between use of oxytocin and other methods for labor induction using multiple linear regression analyses; interaction and mediation analyses to assess the relationship among MIBS-J scores also followed.

RESULTS

Exogenous oxytocin was used during labor on 15 252 (77.4%) participants. After adjusting for confounders, there were no significant differences in adverse MIB between groups for which exogenous oxytocin was used and not used for labor induction.

LIMITATION

The MIBS-J scores at one and six months were compiled using five instead of 10 questions. Moreover, detailed information was unavailable; for example, the questionnaire did not ask for the dosage and timing of the drugs used to induce labor.

CONCLUSIONS

Exogenous oxytocin is a safe and vital drug to induce labor, and has been shown in this study to have no significant impact on long-term adverse MIB.

Relations of mold, stove, and fragrance products on childhood wheezing and asthma: A prospective cohort study from the Japan Environment and Children's Study

This prospective cohort study aimed to examine the associations between mold growth, type of stoves, and fragrance materials and early childhood wheezing and asthma, using data from the Japan Environment and Children's Study. Mold growth at home, usage of kerosene/gas stove, wood stove/fireplace, and air freshener/deodorizer were surveyed using a questionnaire at 1.5-year-old, and childhood wheezing and doctor-diagnosed asthma during the previous year were obtained using a 3-year-old questionnaire. Multilevel logistic regression analysis was performed to evaluate the association between exposure to childhood wheezing and asthma. A total of 60 529 children were included in the analysis. In multivariate analyses, mold growth and wood stove/fireplace had significantly higher odds ratios (ORs) for wheezing (mold growth: 1.13; 95% CI, 1.06-1.22; wood stove/fireplace: 1.23; 95% CI, 1.03-1.46). All four exposures had no significant ORs for childhood doctor-diagnosed asthma; however, in the supplemental analysis of northern regions, wood stove/fireplace had a significantly higher OR for asthma. Mold growth and wood stove/fireplace had significant associations with childhood wheezing in the northern regions. Mold elimination in the dwellings and use of clean heating (no air pollution emissions) should be taken into consideration to prevent and improve childhood wheezing and asthma.

Association of Maternal Total Cholesterol With SGA or LGA Birth at Term: the Japan Environment and Children's Study

CONTEXT

Maternal cholesterol is important for fetal development. Whether maternal serum total cholesterol (maternal TC) levels in midpregnancy are associated with small (SGA) or large (LGA) for gestational age independent of prepregnancy body mass index (BMI) and weight gain during pregnancy is inconclusive.

OBJECTIVE

This work aimed to prospectively investigate the association between maternal TC in midpregnancy and SGA or LGA.

METHODS

The Japan Environment and Children's Study is a nationwide prospective birth cohort study in Japan. Participants in this study included 37 449 nondiabetic, nonhypertensive mothers with singleton birth at term without congenital abnormalities. Birth weight for gestational age less than the 10th percentile and greater than or equal to the 90th percentile were respectively defined as SGA and LGA by the Japanese neonatal anthropometric charts.

RESULTS

The mean gestational age at blood sampling was 22.7 ± 4.0 weeks. After adjustment for maternal age, sex of child, parity, weight gain during pregnancy, prepregnancy BMI, smoking, alcohol drinking, blood glucose levels, household income, and study areas, 1-SD decrement of maternal TC was linearly associated with SGA (odds ratio [OR]: 1.20; 95% CI, 1.15-1.25). In contrast, 1-SD increment of maternal TC was linearly associated with LGA (OR: 1.13; 95% CI, 1.09-1.16). Associations did not differ according to prepregnancy BMI and gestational weight gain (P for interaction > .20).

CONCLUSION

Maternal TC levels in midpregnancy were associated with SGA or LGA in a Japanese cohort. It may help to predict SGA and LGA. Favorable maternal lipid profiles for fetal development must be explored.

Associations between prenatal exposure to volatile organic compounds and neurodevelopment in 12-month-old children: The Japan Environment and Children's Study (JECS)

In recent years, there has been an increase in the number of problems associated with neurodevelopmental disorders in children, and there has been a growing interest in the relationship between environmental chemicals and children's health. The objective of this study was to examine whether an association exists between occupational or environmental prenatal maternal exposure to volatile organic compounds and the risk of neurodevelopmental disorders in children using Japanese translations of the Ages & Stages Questionnaires, Third Edition (J-ASQ-3). An increase in the risk of neurodevelopmental delay in 12-month-old children associated with maternal exposure to formalin or formaldehyde was identified in terms of problem-solving (odds ratio (OR): 1.76, 95% confidence interval (CI): 0.99-3.12) and personal-social skills (OR: 3.32, 95% CI: 1.46-7.55). It is not clear whether or not this tendency is reversible, and whether it is observed past 12 months of age. Further research and a preventive approach are needed.

Airborne fine particulate matter in Japan induces lipid synthesis and inhibits autophagy in HepG2 cells

Inhalation of particulate matter with a diameter less than 2.5 µm has been reported to exacerbates fatty liver disease. However, the components and mechanisms of particulate matter involved in hepatic lipid metabolism and autophagy have not been fully elucidated. We found that atmospheric particulate matter in Japan stimulated lipogenesis in hepatocytes even when its lipid component was removed. Furthermore, we demonstrated that particulate matter did not promote autophagosome formation but inhibited autophagic degradation in hepatocytes. In previous toxicity experiments, particulate matter collected from atmosphere often contained contaminants originating from filters. In this study, we exposed the powdery particulate matter with less contaminants collected using a cyclone and impactor system to HepG2 cells, human hepatocyte. This particulate matter induced lipogenesis and endoplasmic reticulum stress in HepG2 cells as well as previous reports of particulate matter in the USA and China. On the other hand, when autophagic flux were examined in detail, the particulate matter did not promote autophagosome formation, but inhibited autophagic degradation. Since these effects were similar to those of palmitate, a fatty acid, we prepared particulate matter in which lipid component was removed by acetone and compared the effects on HepG2 cells with those of untreated one. The particulate matter without lipid component induced lipid droplets as well as did the untreated one although it induced less endoplasmic reticulum stress. These results suggest that hepatic lipid synthesis is stimulated not only by the uptake of lipid but also by other components in the particulate matter.

SOD2 mRNA as a potential biomarker for exercise: interventional and cross-sectional research in healthy subjects

The health-promoting effects of exercise are explained by the biological adaptation to oxidative stress via maintenance of mitochondrial function especially in muscles. Although the induction of antioxidant enzymes in muscle is a useful indicator of exercise, it is not widely used due to the invasiveness of muscle biopsies. To explore more suitable biomarkers for exercise, we examined mRNA levels of antioxidant enzymes in peripheral blood mono­nuclear cells of 14 volunteers in an exercise intervention study. These results were validated in a cross-sectional study of 392 healthy individuals, and we investigated the association between exercise habits, smoking, alcohol consumption, mitochondrial DNA, malondialdehyde, and various clinical features. The 2-week exercise increased superoxide dismutase 1 at the end of exercise and superoxide dismutase 2 from week 4 onwards. In the cross-sectional study, superoxide dismutase 2 correlated positively with exercise habits and number of mitochondrial DNA, and negatively with malondialdehyde levels. Multivariate binominal regression analysis showed that superoxide dismutase 2 was positively associated with exercise habits in nonsmoking individuals. These results suggest that mRNA levels of superoxide dismutase 2 in blood might be a potentially useful biomarker for exercise in healthy individuals. This study was registered with University Hospital Medical Information Network (No: 000038034).

Development of a parent-reported screening tool for avoidant/restrictive food intake disorder (ARFID): Initial validation and prevalence in 4-7-year-old Japanese children

The prevalence of avoidant/restrictive food intake disorder (ARFID) in the general child population is still largely unknown and validated screening instruments are lacking. The aims of this study were (1) to investigate the prevalence of children screening positive for ARFID in a Japanese birth cohort using a newly developed parent-reported screening tool, (2) to estimate the prevalence of children with ARFID experiencing physical versus psychosocial consequences of their eating pattern, and (3) to provide preliminary evidence for the validity of the new screening tool. Data were collected from 3728 4-7-year-old children born between 2011 and 2014 in Kochi prefecture, Japan (response rate was 56.5%); a sub-sample of the Japan Environment and Children's Study (JECS). Parents completed a questionnaire including the ARFID screener and several other measures to assess convergent validity. The point prevalence of children screening positive for ARFID was 1.3%; half of them met criteria for ARFID based on psychosocial impairment alone, while the other half met diagnostic criteria relating to physical impairment (and additional psychosocial impairment in many cases). Sensory sensitivity to food characteristics (63%) and/or lack of interest in eating (51%) were the most prevalent drivers of food avoidance. Children screening positive for ARFID were lighter in weight and shorter in height, they showed more problem behaviors related to mealtimes and nutritional intake, and they were more often selective eaters and more responsive to satiety, which together provides preliminary support for the validity of the new screening tool. This is the largest screening study to date of ARFID in children up to 7 years. Future studies should examine the diagnostic validity of the new ARFID screener using clinically ascertained cases. Further research on ARFID prevalence in the general population is needed.

Leukocyte Immunoglobulin-Like Receptors in Regulating the Immune Response in Infectious Diseases: A Window of Opportunity to Pathogen Persistence and a Sound Target in Therapeutics

Immunoregulatory receptors are essential for orchestrating an immune response as well as appropriate inflammation in infectious and non-communicable diseases. Among them, leukocyte immunoglobulin-like receptors (LILRs) consist of activating and inhibitory receptors that play an important role in regulating immune responses modulating the course of disease progression. On the one hand, inhibitory LILRs constitute a safe-guard system that mitigates the inflammatory response, allowing a prompt return to immune homeostasis. On the other hand, because of their unique capacity to attenuate immune responses, pathogens use inhibitory LILRs to evade immune recognition, thus facilitating their persistence within the host. Conversely, the engagement of activating LILRs triggers immune responses and the production of inflammatory mediators to fight microbes. However, their heightened activation could lead to an exacerbated immune response and persistent inflammation with major consequences on disease outcome and autoimmune disorders. Here, we review the genetic organisation, structure and ligands of LILRs as well as their role in regulating the immune response and inflammation. We also discuss the LILR-based strategies that pathogens use to evade immune responses. A better understanding of the contribution of LILRs to host-pathogen interactions is essential to define appropriate treatments to counteract the severity and/or persistence of pathogens in acute and chronic infectious diseases lacking efficient treatments.

Maternal exposure to smoking and infant's wheeze and asthma: Japan Environment and Children's Study

BACKGROUND

Evidence regarding independent effects of maternal smoking in different time frames of pregnancy and maternal exposure to secondhand smoke on the development of wheeze/asthma in her offspring is limited. We aimed to investigate the effect of maternal exposure to tobacco smoke on wheeze/asthma development at 1 year of age in her offspring using data from the nationwide birth cohort study in Japan.

METHODS

Pregnant women who lived in the 15 designated regional centers throughout Japan were recruited. We obtained information about maternal smoking or secondhand smoke status and wheeze/asthma development in the offspring from a self-administered questionnaire.

RESULTS

We analyzed 90,210 singleton births. Current maternal smoking during pregnancy increased the risks of wheeze/asthma in the offspring compared with no maternal smoking (wheeze: 1-10 cigarettes/day: adjusted odds ratio (aOR) 1.436, 95% CI 1.270-1.624; ≧11 cigarettes/day: aOR 1.669, 95% CI 1.341-2.078; asthma: 1-10 cigarettes/day: aOR 1.389, 95% CI 1.087-1.774; ≧11 cigarettes/day: aOR 1.565, 95% CI 1.045-2.344). Daily maternal exposure to secondhand smoke during pregnancy also increased the risks of wheeze/asthma in her offspring compared with no secondhand smoke exposure (wheeze: aOR 1.166, 95% CI 1.083-1.256; asthma: aOR 1.258, 95% CI 1.075-1.473). The combination of current maternal smoking during pregnancy and maternal history of allergy increased the risks of wheeze/asthma in her offspring (wheeze: aOR 2.007, 95% CI 1.739-2.317; asthma: aOR 1.995, 95% CI 1.528-2.605).

CONCLUSIONS

We found that current maternal smoking and maternal secondhand smoke exposure during pregnancy increased the risks of wheeze and asthma in her offspring.

Acute effect of the COVID-19 pandemic on emergency transportation due to acute alcoholic intoxication: a retrospective observational study

Background

The COVID-19 pandemic has caused changes in people’s drinking habits and the emergency management system for various diseases. However, no studies have investigated the pandemic’s impact on emergency transportation for acute alcoholic intoxication. This study examines the effect of the pandemic on emergency transportation due to acute alcoholic intoxication in Kochi Prefecture, Japan, a region with high alcohol consumption.

Methods

A retrospective observational study was conducted using data of 180,747 patients from the Kochi-Iryo-Net database, Kochi Prefecture’s emergency medical and wide-area disaster information system. Chi-squared tests and multiple logistic regression analyses were performed. The association between emergency transportation and alcoholic intoxication was examined. The differences between the number of transportations during the voluntary isolation period in Japan (March and April 2020) and the same period for 2016–2019 were measured.

Results

In 2020, emergency transportations due to acute alcoholic intoxication declined by 0.2%, compared with previous years. Emergency transportation due to acute alcoholic intoxication decreased significantly between March and April 2020, compared with the same period in 2016–2019, even after adjusting for confounding factors (adjusted odds ratio 0.67; 95% confidence interval 0.47–0.96).

Conclusions

This study showed that lifestyle changes due to the COVID-19 pandemic affected the number of emergency transportations; in particular, those due to acute alcoholic intoxication decreased significantly.

Compromised glutathione synthesis results in high susceptibility to acetaminophen hepatotoxicity in acatalasemic mice

Acatalasemia is caused by genetic defect in the catalase gene. Human achatalasemia patients are able to scavenge physiological hydrogen peroxide but are vulnerable to exogenous oxidative stress. In the present study, we used an acetaminophen-induced hepatotoxicity model in acatalasemic mice to explore this vulnerability. Interestingly, the acetaminophen-induced decrease in total glutathione levels was more prolonged in acatalasemic mice. While the subunits of glutamate-cysteine ligase, a glutathione synthase enzyme, were increased by acetaminophen in the liver of wild-type mice, their expression was lower and was further reduced by acetaminophen in acatalasemic mice. This feature was also observed in immortalized hepatocytes derived from the livers of these mice. However, when catalase was knocked down in HepG2 cells, a cultured human liver cell line, the expression of glutamate-cysteine ligase subunits was increased, suggesting that the low expression of glutamate-cysteine ligase subunits in acatalasemia may be due to other mechanism than catalase deficiency. Therefore, when other factors were investigated, it was found that transforming growth factor-β1 was up-regulated by acetaminophen in the liver of acatalasemic mice, which may inhibit the expression of glutamate-cysteine ligase subunits. The results of this study suggest a new toxic mechanism of acetaminophen-induced liver injury in patients with acatalasemia.