Pediatric leukemia and maternal occupational exposure to anticancer drugs: the Japan Environment and Children's Study.

ABSTRACT: Occupational exposure to medical agents and ionizing radiation has been suggested as a possible risk factor for childhood cancer. However, the relationship between such exposure and pediatric malignant neoplasms has not yet been comprehensively studied. This cohort study aimed to investigate the association between parental occupational exposure to hazardous medical agents or ionizing radiation and the risk of childhood cancer in offspring. Data from a large birth cohort in Japan, which included 104 062 fetuses, were analyzed. The primary outcome was the development of leukemia or brain tumors diagnosed by community physicians during the first 3 years after birth. Exposure factors were medical agents, including anticancer agents, ionizing radiation, and anesthetics, handled by mothers during pregnancy or by fathers for 3 months before conception. The incidence of leukemia, but not of brain tumors, was higher in mothers exposed to anticancer drugs. Multivariable regression analysis showed that maternal exposure to anticancer drugs was associated with an increased risk of leukemia in offspring older than 1 year (adjusted relative risk, 7.99 [95% confidence interval, 1.98-32.3]). Detailed information obtained from medical certificates of patients with identified leukemia revealed no infant leukemia but acute lymphoblastic leukemias in the exposed group. Our findings suggest that maternal occupational exposure to anticancer drugs may be a potential risk factor for acute lymphoblastic leukemia in offspring older than 1 year. Effective prevention methods may be necessary to prevent maternal exposure to anticancer drugs and to reduce the risk of childhood malignant neoplasms.

Gestational Weight Gain Growth Charts Adapted to Japanese Pregnancies Using a Bayesian Approach in a Longitudinal Study: The Japan Environment and Children's Study.

BACKGROUND: Tracking gestational weight gain (GWG) during pregnancy makes it possible to optimize pregnancy outcomes, and GWG growth curves are well suitable for this purpose. The GWG guidelines for Japanese were revised in 2021. However, currently, there are no GWG growth curves to guide women on how to gain weight to meet these guidelines. METHODS: Using data on 96,631 live births from the Japan Environment and Children's Study (JECS), we created descriptive GWG percentile curves estimating the trajectory of GWG required to meet the GWG guidelines stratified by pre-pregnancy body mass index (BMI). For both analyses, Bayesian mixed models with restricted cubic splines adjusted for maternal characteristics were used. RESULTS: GWG curves substantially differed by pre-pregnancy BMI and were higher among multiparas and those with lower maternal age and with no previous disease. We estimated that underweight, normal weight, overweight, and obese women who gain 8.4 to 11.1 kg, 6.4 to 9.1 kg, 3.8 to 6.5 kg, and <1.9 kg at 30 weeks of gestation are on the trajectory to reach the new guidelines at 40 weeks of gestation. CONCLUSION: We provide GWG percentiles curves for Japanese women, as well as GWG trajectory curves to meet the new GWG recommendations. These results may help pregnant women monitor weight during pregnancy.

Maternal Chronic Disease and Congenital Anomalies of the Kidney and Urinary Tract in Offspring: A Japanese Cohort Study.

RATIONALE & OBJECTIVE: Several maternal chronic diseases have been reported as risk factors for congenital anomalies of the kidney and urinary tract (CAKUT) in offspring. However, these investigations used case-control designs, and cases with isolated genitourinary CAKUT were not distinguished from cases in which CAKUT were present with extrarenal congenital anomalies (complicated CAKUT). We examined the association of maternal diseases with isolated and complicated CAKUT in offspring using data from a prospective cohort study. STUDY DESIGN: A nationwide prospective birth cohort study. SETTING & PARTICIPANTS: 100,239 children enrolled in the Japan Environment and Children's Study between January 2011 and March 2014 at 15 research centers. Physicians' diagnoses in mothers and children were collected from medical record transcripts and questionnaires. EXPOSURES: Medical histories of maternal noncommunicable diseases, including obesity, hypertension, diabetes mellitus, kidney disease, hyperthyroidism, hypothyroidism, psychiatric disease, epilepsy, cancer, and autoimmune disease. OUTCOMES: CAKUT diagnosed during the first 3 years of life, classified as isolated or complicated. ANALYTICAL APPROACH: Multivariable Poisson regression with generalized estimating equations accounting for clustering by clinical center. RESULTS: Among the 100,239 children, 560 (0.6%) had CAKUT, comprising 454 (81%) isolated and 106 (19%) complicated forms. The risk of isolated CAKUT was increased in children of mothers who experienced kidney disease (adjusted risk ratio [RR], 1.80 [95% CI, 1.12-2.91]) or cancer (RR, 2.11 [95% CI, 1.15-3.86]). Furthermore, the risk of complicated CAKUT was increased in children of mothers with diabetes mellitus (RR, 3.04 [95% CI, 1.64-5.61]). LIMITATIONS: Lack of standardization or prespecification of clinical definitions, diagnostic criteria, measurements, and testing. Genetic testing was not performed. CONCLUSIONS: Isolated CAKUTs and complicated CAKUTs were associated with different maternal diseases. The results may inform clinical management of pregnancy and highlight potential differences in the genesis of isolated and complicated forms of CAKUT.

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 1st 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 2nd 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 1st trimester. Women with weight loss ≥ 5% in the 1st 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 2nd trimester, women with weight loss ≥ 5% in the 1st 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 2nd 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 2nd trimester.

The earliest enzyme replacement for infantile-onset Pompe disease in Japan.

BACKGROUND: Infantile-onset Pompe disease (IOPD) is the most severe phenotype of a lysosomal storage disorder caused by acid alpha-glucosidase (GAA) deficiency. An enzymatic newborn screening (NBS) program started regionally in Japan in 2013 for early enzyme replacement therapy (ERT). We report the ERT responses of the first NBS-identified Japanese IOPD case and of another case diagnosed prior to NBS, to discuss the problems of promptly starting ERT in Japan. METHODS: Acid alpha-glucosidase activity was measured by fluorometric assay in both patients. The diagnosis of IOPD was confirmed by next-generation followed by Sanger-method sequencing (patient 1) or direct sequencing of polymerase chain reaction (PCR)-amplified products (patient 2) of the GAA gene. RESULTS: A female infant identified by NBS had a novel out-of-frame (p.F181Dfs*6) variant and a reported pathogenic (p.R600C) variant, along with two pseudodeficiency variants. Enzyme replacement therapy was started at age 58 days when the infant had increased serum levels of creatine kinase and slight myocardial hypertrophy. Clinical and biochemical markers improved promptly. She has been alive and well without delayed development at age 14 months. Patient 2, a Japanese male, received a diagnosis of IOPD at age 5 months before the NBS era. He had a homozygotic variant of GAA (p.R608X), later registered as a cross-reactive immunological material (CRIM)-negative genotype, and developed a high titer of anti-rhGAA antibodies. The patient has survived myocardial hypertrophy with continuous respiratory support for 12 years of ERT. CONCLUSIONS: Enzyme replacement therapy should not be delayed over the age of 2 months for reversible cardiac function, although CRIM-negative cases may hamper turnaround time reduction.

Fluctuations of aeroallergen-specific immunoglobulins and children's allergic profiles: Japan Environment & Children's Study of a pilot cohort.

BACKGROUND: Allergen-specific immunoglobulins have a crucial role in allergic diseases. Most wheeze episodes develop before school age, and allergic rhinitis later develops during early elementary school years. However, the clinical background and cytokine/chemokine profiles associated with changes in immunoglobulins during early school-age are poorly understood. METHODS: This study used blood samples from children participating in the JECS Pilot Study. We examined nineteen kinds of aeroallergen-specific immunoglobulins (IgE, IgG1, IgG4, and IgA) levels in patients at age 6 and age 8. Fluctuations of Der f 1- and Cry j 1-specific immunoglobulins levels during the two periods were compared to assess the frequency of allergic statuses and clusters of cytokine/chemokine profiles. RESULTS: The medians of aeroallergen-specific IgE levels did not fluctuate, and almost all IgG1 and IgG4 decreased. In IgA, four (e.g., Der f 1) increased, whereas the other four (e.g., Cry j 1) decreased. The ratio of the Der f 1-specific IgG1 level at age 8 to that at age 6 was higher in children with poor asthma control than in children with better asthma control. Moreover, the cytokine/chemokine cluster with relatively lower IL-33 and higher CXCL7/NAP2 was associated with lower Der f 1- and Cry j 1-specific IgG4 levels, but not IgE levels. CONCLUSIONS: The cluster of cytokine/chemokine profiles characterized by lower IL-33 and higher CXCL7/NAP2 was associated with the maintenance of aeroallergen-specific IgG4 levels. This result provides a basis for considering the control of aeroallergen-specific immunoglobulins.

Possible association between early formula and reduced risk of cow's milk allergy: The Japan Environment and Children's Study.

BACKGROUND: Despite evidence for the protective effects of early regular exposure to peanut and egg proteins against allergies, the optimal timing of cow's milk (CM) protein exposure is unknown. OBJECTIVE: We aimed to determine when during the first year of life CM-based formula consumption becomes associated with lower CM allergy (CMA) risk. METHODS: We used the data set of the Japan Environment and Children's Study (JECS), a nationwide birth cohort involving over 100 000 mother-child pairs. CMA was defined as an allergic reaction to a CM product in an individual not consuming CM products at the time of evaluation, combined with physician-diagnosed food allergy. For each exposure, we identified when formula milk was commenced, and its consumption status during 0-3, 3-6 and 6-12 months old. RESULTS: The prevalence of CMA was 0.23% and 1.03% at 6 and 12 months old, respectively. Multivariable regression analyses revealed that introducing regular consumption of formula within the first 3 months of age was associated with lower risk of CMA at 12 months. Regular consumption at 3-6 months was strongly associated with a reduction in 12-month CMA (adjusted relative risks [95% confidence intervals]: 0.22 [0.12-0.35]), whereas no association was observed at 0-3 months (1.07 [0.90-1.27]). CONCLUSION AND CLINICAL RELEVANCE: Regular exposure to formula milk at age 3 months or older is associated with lower CMA at 12 months old, suggesting that the effect of very early CM exposure on CMA may disappear if the exposure is brief. At present, however, the results of this observational study should not be used for formula recommendation and randomized controlled trials are required to confirm this association.

GNAO1 organizes the cytoskeletal remodeling and firing of developing neurons.

Developmental and epileptic encephalopathy (DEE) represents a group of neurodevelopmental disorders characterized by infantile-onset intractable seizures and unfavorable prognosis of psychomotor development. To date, hundreds of genes have been linked to the onset of DEE. GNAO1 is a DEE-associated gene encoding the alpha-O1 subunit of guanine nucleotide-binding protein (GαO ). Despite the increasing number of reported children with GNAO1 encephalopathy, the molecular mechanisms underlying their neurodevelopmental phenotypes remain elusive. We herein present that co-immunoprecipitation and mass spectrometry analyses identified another DEE-associated protein, SPTAN1, as an interacting partner of GαO . Silencing of endogenous Gnao1 attenuated the neurite outgrowth and calcium-dependent signaling. Inactivation of GNAO1 in human-induced pluripotent stem cells gave rise to anomalous brain organoids that only weakly expressed SPTAN1 and Ankyrin-G. Furthermore, GNAO1-deficient organoids failed to conduct synchronized firing to adjacent neurons. These data indicate that GαO and other DEE-associated proteins organize the cytoskeletal remodeling and functional polarity of neurons in the developing brain.

Infantile neuroblastoma and maternal occupational exposure to medical agents.

BACKGROUND: Healthcare workers are often exposed to hazardous agents and are at risk for adverse health consequences that affect not only themselves but also their infants. This study aimed to examine whether such occupational exposure increased the risk of childhood cancer in offspring. METHODS: We used the dataset of the Japan Environment and Children's Study, a nationwide birth cohort involving over 100,000 mother-child pairs. Information was obtained via successive questionnaires that were completed until the child turned 1 year of age. The parents were asked whether they occupationally handled medical agents during pregnancy. RESULTS: A total of 26 infants developed neoplasms: neuroblastoma, leukemia, and brain tumor. The incidence of neuroblastoma was significantly higher in infants whose mothers were exposed to radiation (3/2142: 140.1 per 100,000 population) than in those who were not (12/90,384: 13.3 per 100,000 population). Multivariable regression analyses revealed a close association between maternal irradiation and the development of neuroblastoma (adjusted incident rate ratio: 10.68 [95% confidence interval: 2.98‒38.27]). CONCLUSIONS: The present study demonstrated, for the first time, a potential association between maternal occupational exposure and the occurrence of neuroblastoma in offspring. Further studies involving the large pediatric cancer registries are needed to confirm these preliminary results. IMPACT: Healthcare workers are often exposed to hazardous agents and are at risk for adverse health consequences that affect not only themselves but also their infants. This study examined the association between such occupational exposure and offspring's cancers that developed until the age of 1 year. Maternal exposure to ionizing radiation was associated with infantile neuroblastoma in offspring. Further studies involving the large pediatric cancer registries are needed to confirm these preliminary results.

Physical growth and neurodevelopment during the first year of life: a cohort study of the Japan Environment and Children's Study.

BACKGROUND: The association between a slower physical growth and poorer neurodevelopment has been established in infants born preterm or small for gestational age. However, this association is inconsistent in term-born infants, and detailed investigations in infancy, when intervention is most beneficial for improving outcomes, are lacking. We therefore examined this association separately by sex during the first year of life in term-born infants. METHODS: Using data collected until children reached 12 months old in an ongoing prospective cohort of the Japan Environment and Children's Study, we analyzed 44,264 boys and 42,541 girls with singleton term-birth. The exposure variables were conditional variables that disentangle linear growth from weight gain relative to linear growth, calculated from the length and weight at birth and 4, 7 and 10 months old. Neurodevelopmental delay was identified using the Japanese-translated version of Ages & Stages Questionnaires, third edition. RESULTS: A reduced risk of neurodevelopmental delay at 6 months old was observed in children with a higher birth weight (adjusted relative risks [aRRs]: 0.91 and 0.93, 95 % confidence intervals [95 % CIs]: 0.87-0.96 and 0.88-0.98 in boys and girls, respectively) and increased linear growth between 0 and 4 months old (aRRs: 0.85 and 0.87, 95 % CIs: 0.82-0.88 and 0.83-0.91 in boys and girls, respectively). A reduced risk at 12 months was found in children with an increased linear growth between 0 and 4 months (aRRs: 0.92 and 0.90, 95 % CIs: 0.87-0.98 and 0.84-0.96 in boys and girls, respectively), boys with an increased relative weight gain between 0 and 4 months (aRR: 0.90, 95 % CI: 0.84-0.97), and girls with a higher birth weight (aRR: 0.89, 95 % CI: 0.83-0.96). CONCLUSIONS: These results suggest that a slow physical growth by four months old may be a predictor of neurodevelopmental delay during infancy.

[Environmental factors for the development of hematopoietic neoplasms in children].

Parental age at birth has been investigated in patients diagnosed with pediatric cancer. The Japan Children's Cancer Registry1985-2007 recruited 5,510 patients with leukemia and 8,782 with other cancers. The proportion of patients born to mother and father aged >40 years showed a higher trend in leukemia than that in other cancers (odds ratio [OR] 1.41, p=0.057), especially in <12-month-old infants born to mother aged >40 years (OR 2.55, p=0.031). We then divided 27,335 patients diagnosed in 1969-2006 into every 8-year birth cohorts to compare proportions of mothers with prenatal medical irradiation. The OR of leukemia was higher than that of other cancers in 1969-1976 (1.25) or 1977-1984 (1.39), which reached statistical significance. We have also studied caregiver's exposure to anticancer drugs. In 15 pediatric patients with cancer who received cyclophosphamide (CPM), the concentration was measured using mothers and medical staff's urine. Five of 7 infants' and 2 of 8 adolescent's mothers showed increased urine CPM levels. CPM was not detected in any medical staff's samples. Maternal exposure to anticancer drugs should also be considered. Efforts of reducing the genotoxicity in both infants and mothers are crucial for pediatric cancer prevention.

Exploratory analysis of plasma cytokine/chemokine levels in 6-year-old children from a birth cohort study.

This study aimed to reveal a new dimension of allergy profiles in the general population by using machine learning to explore complex relationships among various cytokines/chemokines and allergic diseases (asthma and atopic dermatitis; AD). We examined the symptoms related to asthma and AD and the plasma levels of 72 cytokines/chemokines obtained from a general population of 161 children at 6 years of age who participated in a pilot birth cohort study of the Japan Environment and Children's Study (JECS). The children whose signs and symptoms fulfilled the criteria of AD, which are mostly based on questionnaire including past symptoms, tended to have higher levels of the two chemokine ligands, CCL17 and CCL27, which are used for diagnosis of AD. On the other hand, another AD-related chemokine CCL22 level in plasma was higher only in children with visible flexural eczema, which is one of AD diagnostic criteria but was judged on the same day of blood examination unlike other criteria. Here, we also developed an innovative method of machine learning for elucidating the complex cytokine/chemokine milieu related to symptoms of allergic diseases by using clustering analysis based on the random forest dissimilarity measure that relies on artificial intelligence (AI) technique. To our surprise, the majority of children showing at least any asthma-related symptoms during the last month were divided by AI into the two clusters, either cluster-2 having elevated levels of IL-33 (related to eosinophil activation) or cluster-3 having elevated levels of CXCL7/NAP2 (related to neutrophil activation), among the total three clusters. Future studies will clarify better approach for allergic diseases by endotype classification.

Management of apnea in infants with trisomy 18.

This case series aimed to characterize the clinical features, management, and outcomes of apnea in infants with trisomy 18. Participants in this study were infants with trisomy 18 who were born alive and admitted to the neonatal intensive care unit in Kyushu University Hospital from 2000 to 2018. Retrospective analysis was performed on clinical data recorded in our department. Twenty-seven infants with trisomy 18 were admitted to our hospital during the study period, of which 25 (nine males, 16 females) were enrolled as eligible participants in this study. Among them, 14 started presenting with apnea from median 3.5 days of age (range 0-47d). In these infants with apnea, eight received respiratory support of positive pressure ventilation (PPV). The 1-year survival rate of infants in the PPV group was higher than that of non-PPV-supported infants (5 out of 8 vs 0 out of 6 infants). Five PPV-supported infants received a diagnosis of epilepsy, which was controlled by antiepileptic drugs. Postnatal respiratory intervention provides better prognosis in infants with trisomy 18. Improved survival leads to accurate diagnosis and treatment of apneic events in association with epilepsy. WHAT THIS PAPER ADDS: Respiratory support is effective against apnea in infants with trisomy 18. Intervention with ventilation provides a higher chance of prolonged survival. Improved survival leads to the accurate diagnosis and treatment of epilepsy-associated apnea.

A Nationwide Survey of Pediatric-onset Japanese Encephalitis in Japan.

BACKGROUND: Japanese encephalitis (JE) is the leading cause of viral encephalitis with high mortality and morbidity in Asia. In Japan, however, the active recommendation of JE vaccine was retracted in 2005 because of the potential risk of acute disseminated encephalomyelitis. We aimed to determine the recent incidence of childhood-onset JE after the domestic change of vaccination policy in Japan, and to analyze the clinical features of affected children. METHODS: A retrospective nationwide survey was conducted for pediatric patients with JE in Japan from 1995 to 2015. The national surveillance system was used to identify the pediatric patients with JE. Follow-up questionnaires were sent to analyze their clinical and neuroimaging profiles. RESULTS: Among a total of 109 patients registered to the national surveillance, 10 (9%) were less than age 15 years. The annual incidence rate of childhood-onset JE was higher during 2005-15 than that during 1995-2004 (4.3 × 10-3 vs 1.1 × 10-3 per 100000, respectively; P = .04). Endemic regions overlapped with prefectures that farmed pigs harboring antibodies against JE virus with high prevalence. Detailed clinical data were collected from 9 patients. None of them died, but 5 of 9 patients (56%) had neurological sequelae after recovery. One patient who was partially vaccinated with 2 doses of JE vaccine fully recovered from a coma. The age of 3 years or less was associated with unfavorable neurological prognosis. CONCLUSIONS: Our data provide evidence for the importance and prophylactic effect of the JE vaccine in young children in the endemic area.

Associations Between Metal Levels in Whole Blood and IgE Concentrations in Pregnant Women Based on Data From the Japan Environment and Children's Study.

BACKGROUND: Metal exposures could possibly affect allergic responses in pregnant women, although no studies have yet shown a clear relationship between the two, and such exposures might also affect the development of allergic diseases in children. METHODS: We investigated the relationship between metal concentrations in whole blood and immunoglobulin E (IgE; total and specific) in 14,408 pregnant women who participated in the Japan Environment and Children's Study. The subjects submitted self-administered questionnaires, and blood samples were collected from them twice, specifically, during the first trimester and again during the second/third trimester. Concentrations of the metals Cd, Pb, Hg, Se, and Mn, as well as serum total and allergen-specific IgEs for egg white, house dust-mites (HDM), Japanese cedar pollen (JCP), animal dander, and moth, were measured. Allergen-specific IgE(s) were divided based on concentrations <0.35 or ≥0.35 UA/mL, and the metal levels were divided into quartiles. RESULTS: Multivariable logistic regression analysis showed that there was a significant negative correlation between HDM- and animal dander-specific IgEs and Hg and Mn concentrations. Conversely, there was a significant positive relationship between JCP-specific IgE and Hg and Se concentrations. CONCLUSIONS: Metal exposures may be related to both increases and decreases in allergen-specific IgEs in pregnant women.

Impact of sleep duration during pregnancy on the risk of gestational diabetes in the Japan environmental and Children's study (JECS).

BACKGROUND: Gestational diabetes mellitus (GDM) has serious effects on both mother and child. Like Type 2 Diabetes Mellitus, it is increasing in prevalence world-wide. In addition to obesity, sleep duration has been named an important risk factor. Using a large cohort study, including data from 48,787 participants of the Japan Environment and Children's Study (JECS), we examined the association between sleep duration and both random blood glucose levels and GDM rates during pregnancy. METHODS: Random blood glucose levels were measured during pregnancy. GDM diagnosis was based on the results of 75 g oral glucose tolerance test. Additional anthropometric data was collected from questionnaires for statistical analysis. RESULTS: Compared to mothers averaging 7 to < 10 h sleep (reference group), women receiving < 5 h or ≥ 10 h sleep exhibited significantly elevated random blood glucose levels. This was associated with an elevated risk for positive GDM screening (< 5 h sleep: OR 1.17 (0.96-1.44) p = 0.126; ≥10 h sleep: OR 1.13 (1.03-1.25) p = 0.006). Calculating the risk for GDM, women sleeping < 5 h or ≥ 10 h exhibited elevated risks of 1.31-fold and 1.21 respectively. However, this trend was not found to be significant. CONCLUSIONS: Sleep is a critical factor in glucose metabolism, with both abnormally long and short sleep duration increasing random blood glucose levels in pregnant women. Moreover, the risk for positive GDM screening increases significantly with elevated sleep, ≥10 h per night. These findings are promising because they support the idea that sleep duration is a modifiable risk factor, and can be focused upon to improve health and pregnancy outcome.

Psychometric profile of the Ages and Stages Questionnaires, Japanese translation.

BACKGROUND: This study assessed the psychometric profile of 10 questionnaires (every 6 months, from 6 to 60 months) from the Japanese translation of the Ages and Stages Questionnaires, third edition (J-ASQ-3). METHODS: Data from 439 children in a birth cohort were used to identify the J-ASQ-3 score distribution, establish cut-off scores, and calculate the instrument's internal consistency. Data were also collected from 491 outpatients to examine J-ASQ-3 test-retest reliability and concurrent validity, which was examined using the Kyoto Scale of Psychological Development (KSPD) and the Japanese version of the Denver Developmental Screening Test II (J-Denver II). Both the original and the alternative screening criteria of the ASQ-3 were used (failure in at least one and at least two domains, respectively). RESULTS: Cronbach's alpha for each J-ASQ-3 subscale on each questionnaire ranged from 0.45 to 0.89. Test-retest reliability was >0.75 for the subscales on almost all questionnaires. Concurrent validity was also adequate. In comparison with the screening results of the KSPD, the overall sensitivity and specificity were 96.0% and 48.8%, respectively, when the ASQ-3 original criterion was used, and 92.1% and 74.9%, respectively, when the alternative criterion was used. In comparison with the screening results of the J-Denver II, the overall sensitivity and specificity were 75.6% and 74.7%, respectively, when the ASQ-3 original criterion was used, and 56.3% and 93.0%, respectively, when the alternative criterion was used. CONCLUSIONS: This study quantified the psychometric profiles of the Japanese translations of 10 ASQ-3 questionnaires. We demonstrated the validity of the J-ASQ-3 and determined new cut-off scores. Further studies with larger samples from a greater range of locations are required to clarify the suitability of this tool for all Japanese children.

Associations between metal concentrations in whole blood and placenta previa and placenta accreta: the Japan Environment and Children's Study (JECS).

BACKGROUND: Placenta previa and placenta accreta associate with high morbidity and mortality for both mothers and fetus. Metal exposure may have relationships with placenta previa and placenta accreta. This study analyzed the associations between maternal metal (cadmium [Cd], lead [Pb], mercury [Hg], selenium [Se], and manganese [Mn]) concentrations and placenta previa and placenta accreta. METHODS: We recruited 17,414 women with singleton pregnancies. Data from a self-administered questionnaire regarding the first trimester and medical records after delivery were analyzed. Maternal blood samples were collected to measure metal concentrations. The subjects were classified into four quartiles (Q1, Q2, Q3, and Q4) according to metal concentrations. RESULTS: The odds ratio for placenta previa was significantly higher among subjects with Q4 Cd than those with Q1 Cd. The odds ratio for placenta previa was significantly higher for subjects with Q2 Pb than those with Q1 Pb. CONCLUSION: Participants with placenta previa had higher Cd concentrations. However, this study was cross-sectional and lacked important information related to Cd concentration, such as detailed smoking habits and sources of Cd intake. In addition, the subjects in this study comprised ordinary pregnant Japanese women, and it was impossible to observe the relationship between a wide range of Cd exposure and placenta previa. Therefore, epidemiological and experimental studies are warranted to verify the relationship between Cd exposure and pregnancy abnormalities.

Optimal protein intake during pregnancy for reducing the risk of fetal growth restriction: the Japan Environment and Children's Study.

Clinical trials show that protein supplement increases infant size in malnourished populations; however, epidemiological studies in high-income countries have reported mixed results. Although these findings suggest a non-linear relationship between maternal macronutrient intake and fetal growth, this relationship has not been closely examined. We assessed the association between maternal protein intake and fetal growth among 91 637 Japanese women with singletons in a nation-wide cohort study using validated FFQ. The respondents answered the FFQ twice, once during early pregnancy (FFQ1; 16·3 (sd 6·0) weeks), and second during mid-pregnancy (FFQ2, 28·1 (sd 4·1) weeks). Daily energy intake and percentage energy from protein, fats and carbohydrates were 7477 (sd 2577) kJ and 13·5 (sd 2·0), 29·5 (sd 6·5) and 55·3 (sd 7·8) %, respectively, for FFQ1, and 7184 (sd 2506) kJ and 13·6 (sd 2·1), 29·8 (sd 6·6) and 55·3 (sd 7·9) %, respectively, for FFQ2. The average birth weight was 3028 (sd 406) g, and 6350 infants (6·9 %) were small for gestational age (SGA). In both phases of the survey, birth weight was highest and the risk of SGA was lowest when the percentage energy from protein was 12 %, regardless of whether isoenergetic replacement was with fat or carbohydrates. Furthermore, when protein density in the maternal diet was held constant, birth weight was highest when 25 % of energy intake came from fat and 61 % came from carbohydrates during early pregnancy. We found maternal protein intake to have an inverse U-curve relationship with fetal growth. Our results strongly suggest that the effect of protein on birth weight is non-linear, and that a balanced diet fulfilling the minimum requirement for all macronutrients was ideal for avoiding fetal growth restriction.