森 千里

The pathogenesis of congenital diaphragmatic hernia (CDH) is largely unknown; however, vitamin A seems to play a role in diaphragmatic development. Previous case-control studies reported that maternal dietary vitamin A intake was inversely associated with the risk of CDH. To our knowledge, however, there is no prospective evidence regarding this association. Our aim was to examine whether maternal intake of vitamin A was associated with CDH occurrence. Baseline data, from the Japan nationwide birth cohort study (2011-2014) of 89 658 mothers (mean age at delivery = 31 center dot 2 years) who delivered singleton live births, were analysed. We assessed dietary habits using an FFQ focused on the first trimester and estimated the daily intake of total vitamin A (retinol activity equivalents), retinol, provitamin A carotenoids and vegetables. The occurrence of CDH was ascertained from medical records. A total of forty cases of CDH were documented. The adjusted OR of CDH occurrence for the high total vitamin A intake category (median = 468 mu g/d) was 0 center dot 6 (95 % CI 0 center dot 3, 1 center dot 2) with reference to the low intake category (230 mu g/d). When we restricted to mothers with a prepregnancy BMI of 18 center dot 5-24 center dot 9 kg/m(2), vitamin A intake was inversely associated with the risk of their children being born with CDH (OR 0 center dot 5, 95 % CI 0 center dot 2, 1 center dot 0). Even given the limited number of cases in the study, our findings provide additional evidence to link vitamin A with CDH.

There have been no large, nationwide, birth cohort studies in Japan examining the effects of house renovation during pregnancy on congenital abnormality. This study examined the impact of (1) prenatal exposure to house renovation and (2) maternal occupational exposure to organic solvents and/or formaldehyde on the incidence of congenital abnormality. The fixed data of 67,503 singleton births from a large national birth cohort study that commenced in 2011 were used to evaluate the presence of congenital abnormalities and potential confounding factors. We employed multiple logistic regression analysis to search for correlations between maternal exposure to house renovation or organic solvents and/or formaldehyde during pregnancy and such congenital abnormalities as congenital heart disease, cleft lip and/or palate, male genital abnormality, limb defect, and gastrointestinal obstruction. After controlling for potential confounding factors, we observed that house renovation was significantly associated with male genital abnormality (OR 1.81, 95% CI 1.03-3.17, P = 0.04) when stratified by congenital abnormality, with no other remarkable relations to house renovation or occupational use of organic solvents and/or formaldehyde during pregnancy. There were also significant correlations for maternal BMI before pregnancy, history of ovulation induction through medication, maternal diabetes mellitus/gestational diabetes mellitus, and hypertensive disorder of pregnancy with an increased risk of congenital abnormality. In conclusion, this large nationwide survey provides important information on a possible association of house renovation during pregnancy with congenital male genital abnormality which needs confirmation in future studies.

Background: Placenta accreta spectrum (PAS) is a life-threating complication in the field of obstetrics. Sometimes we face with unexpected PAS cases which is potentially higher maternal mortality and morbidity compared with expected cases. The present study was conducted to examine the prevalence of PAS and to elucidate its risk factors using a large Japanese birth cohort study. Methods: We reviewed the results of a nationwide prospective birth cohort study in Japan, and identified 90,554 participants treated from 2011 to 2014 in 15 regional centers. Multiple regression models were created to identify the risk factors for PAS. These data were obtained from self-reported questionnaires or patient medical records. Results: This analysis consisted of 202 cases of PAS (18 with placenta previa and 184 without placenta previa) and 90,352 cases without PAS. The multiple logistic regression analysis showed that placenta previa (adjusted odds ratio [aOR]: 12.86, 95% confidence interval [CI] 7.70-21.45, P &lt 0.001), assisted reproductive technology-related pregnancies (aOR: 6.78, 95% CI 4.54-10.14, P &lt 0.001), smoking during pregnancy (aOR: 1.95, 95% CI 1.15-3.31, P = 0.013), more than two previous cesarean sections (aOR: 2.51, 95% CI 1.35-4.67, P = 0.004), and uterine anomalies (aOR: 3.97, 95% CI 1.24-12.68, P = 0.020) increased the risk of PAS. Conclusion: In general population, placenta previa, assisted reproductive technology-related pregnancy, smoking during pregnancy, repeated cesarean sections, and uterine anomalies were risk factors for PAS in the Japanese population.

Objective: Our study was conducted to examine the association between breastfeeding and febrile seizures (FS) in the first year of life.Methods: We used data from a birth cohort study, the Japan Environment and Childrens Study (JECS). In a self-administered questionnaire, we asked participants the duration of breastfeeding and whether their children were diagnosed as having FS during their first 12 months. We estimated the association of duration and exclusiveness of breastfeeding with the FS by using multiple logistic regression analysis.Results: Of 84,082 children, 995 (1.2%) were diagnosed as having FS by the age of 12 months. The prevalence of FS was higher in children who were breastfed for shorter duration. Multiple logistic regression analysis showed that, compared with children breastfed for less than 1 month, those breastfed for 4-6 months and 7-12 months had lower risks of FS (adjusted odds ratio [aOR], 0.65 [95% confidence interval {CI}, 0.42-0.99]; aOR, 0.66 [95% CI: 0.45-0.96], respectively). Moreover, compared with infants who received both breast milk and formula milk for 6 months, infants who were breastfed exclusively for 6 months had lower risk of FS (aOR: 0.78 [95% CI: 0.64-0.95]).Conclusions: Our results suggest that breastfeeding has a protective effect against FS in the first year of life. (C) 2019 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

This study aimed to clarify the interannual changes in intimate partner violence against pregnant women after the March 11, 2011 Great East Japan Earthquake in target areas of Miyagi Prefecture that were damaged by the earthquake and tsunami. Because of this disaster, in Miyagi Prefecture, approximately 12,000 people died or went missing, and approximately 238,000 buildings were destroyed. According to the U.S. Geological Survey, the Great East Japan Earthquake is the fourth largest earthquake in the world and the largest in Japan since 1900. The present study was part of the Japan Environment and Children's Study. Data from June 2011 to May 2014 of 79,222 pregnant women were analyzed, calculating the prevalence of physical and mental intimate partner violence in the inland, north coastal, and south coastal areas of Miyagi. These prevalence rates were compared with nationwide rates of intimate partner violence in 2011 using univariate and logistic regression analyses. After the disaster, the incidence of mental intimate partner violence increased in the south coastal area and then improved later (19.4%, 13.1%, and 13.3% for south coastal area, and 13.8%, 13.8%, and 13.1% for nationwide in 2011, 2012, and 2013, respectively). However, in the north coastal area, the incidence of physical intimate partner violence increased after the disaster and then improved later (2.7%, 1.5%, and 1.3% for north coastal area, and 1.4%, 1.3%, and 1.1% for nationwide in 2011, 2012, and 2013, respectively). In the inland area, however, the prevalence of both mental and physical intimate partner violence was consistently higher than nationwide rates after the disaster.

The Japan Environment and Children’s Study (JECS) is a birth-cohort study of 100,000 mother–child dyads that aims to investigate the effect of the environment on child health and development. Mercury (Hg), lead (Pb), cadmium (Cd), manganese (Mn) and selenium (Se) are considered to be important co-exposures when examining the effect of other chemical substances on child development. The levels of these elements in the blood of 20,000 randomly selected mid/late-term pregnant women from the whole JECS cohort were analysed using inductively coupled plasma-mass spectrometry. The median concentrations (interquartile ranges) for Pb, Hg, Cd, Mn and Se were 0.63 (0.51–0.78) µg dl−1, 3.83 (2.70–5.43) µg l−1, 0.70 (0.52–0.95) µg l−1, 16.1 (13.2–19.6) µg l−1 and 178 (165–192) µg l−1, respectively. Hg and Se correlated positively with each other (Spearman’s ρ = 0.287), as did Pb and Cd (ρ = 0.239) and Cd and Mn (ρ = 0.267). The blood Pb levels decreased by 5–10-fold over the past 25 years. The main predictors of the blood levels of each element were fish consumption for Hg, maternal age and non-alcoholic beverage consumption for Pb, maternal age and smoking for Cd, gestational age at sampling for Mn and serum protein levels for Se. These results revealed the historical trends and current predictors of the blood levels of these elements in pregnant Japanese women.

Background: Some studies have indicated that female birth and multiple births were risk factors for nausea and vomiting during pregnancy (NVP). The results, however, were conflicting. Our study was conducted to evaluate the association of maternal NVP with fetal sex in singleton and twin pregnancies.Methods: We used the data set from a birth cohort study, the Japan Environment and Children's Study (JECS). In the self-administered questionnaire, participants were asked whether they experienced NVP prior to 12 gestational weeks. Main outcome measures were the presence of NVP and severity of NVP. We estimated the association of fetal sex and birth plurality with NVP using logistic regression analysis, followed by interaction analysis.Results: Of 91,666 women, 75,828 (82.7%) experienced at least some symptoms of NVP and 10,159 (11.1%) experienced severe NVP. Women with female pregnancies and twin pregnancies had higher odds for the presence of NVP and severe NVP compared to women with male pregnancies and singleton pregnancies, respectively. Moreover, of mothers with twin pregnancies, higher odds for the presence of NVP and severe NVP were reported when one or both infants were female, compared to those in which both infants were male. There was no significant interaction between fetal sex and birth plurality.Conclusions: Female sex birth and multiple births are risk factors for the presence of NVP, and especially for severe NVP without interaction. These findings suggest that a factor abundant in the female fetus associates with the severity of NVP.

Maternal exposure to polychlorinated biphenyls (PCBs) results in abnormal fetal development, possibly because of epigenetic alterations. However, the association between PCB levels in cord serum with fetal DNA methylation status in cord tissue is unclear. This study aims to identify alterations in DNA methylation in cord tissue potentially associated with PCB levels in cord serum from a birth cohort in Chiba, Japan (male neonates = 32, female neonates = 43). Methylation array analysis identified five sites for female neonates (cg09878117, cg06154002, cg06289566, cg12838902, cg01083397) and one site for male neonates (cg13368805) that demonstrated a change in the methylation degree. This result was validated by pyrosequencing analysis, showing that cg06154002 (tudor domain containing 9: TDRD9) in cord tissue from female neonates is significantly correlated with total PCB levels in cord serum. These results indicate that exposure to PCBs may alter TDRD9 methylation levels, although this hypothesis requires further validation using data obtained from female neonates. However, since the present cohort is small, further studies with larger cohorts are required to obtain more data on the effects of PCB exposure and to identify corresponding biomarkers.

We evaluated the relationship between preconception folic acid supplementation and the occurrence of neural tube defects (NTDs) in offspring, using data from the Japan Environment and Children's Study (a nationwide prospective birth cohort study) database. Of 92 269 participants with single pregnancies, 74 cases (offspring or fetuses) had NTDs, including 32 cases of spina bifida, 24 cases of anencephaly, and 19 cases of encephalocele. A total of 7634 participants (8.27%) used preconception folic acid supplementation, and of these, 621 (0.67%) also took in dietary folic acid at >= 480 mu g/day. Multivariate logistic regression analyses demonstrated no association between preconception folic acid supplementation and NTDs in offspring or fetuses (odds ratio [OR] 0.622; 95% confidence interval [CI]: 0.226-1.713). Moreover, the participants who combined preconception folic acid supplement use with dietary folic acid intake >= 480 mu g/day demonstrated no incidence of NTDs in offspring or fetuses. Our analysis is limited by the absence of the data on the daily amount of supplementary folic acid intake, requiring careful attention to the interpretation. Additional surveys are required in Japan to resolve those limitations for further comprehensive assessment.

type:text [要旨] 千葉大学では世界を視野に入れ多種多様な考えを理解し，対応できるグローバルな人材育成のため，国際化の推進を行っている。特にヨーロッパにおいてはドイツ連邦共和国の首都であるベルリンのCharit?-Universit?tsmedizin Berlin （シャリテ・ベルリン医科大学）と2010年に5 年間の大学間交流協定を締結して連携活動が始まり，2015年にはさらに2020年まで更新された。2015年にはシャリテ内に千葉大学ジャーマンセンターベルリンオフィスを開設し，両大学長の相互訪問やシンポジウム開催，共同研究の立ち上げなどを進めている。小論では特に最近3 年間の活動を中心に千葉大学とシャリテの共同作業について研究，教育分野などの現状と将来の展望をまとめた。 [SUMMARY] Chiba University is promoting internationalization in order to develop global human resources that can respond to and understand a wide variety of ideas with a view of the world. Especially in Europe, the first agreement was concluded in 2010 with the Charit?-Universit?tsmedizin Berlin, the capital of Germany Federal Republic, and the cooperation activities were carried out. In 2015, the first period of five years ended, and now the second phase（2015 to 2020）is running. In 2015, we established the Chiba University German Center Berlin Office in the Charit? and are working on a more active partnership.This paper summarizes the current activities and future prospects of the joint work of the Chiba University and the Charit? in the field of research and education,especially in the recent two-year activities.

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.

Background: Few previous studies have investigated the association between prenatal caffeine intake and birth size (small for gestational age [SGA], preterm birth, and birthweight Z-score) in Japan. Objectives: We examined the dose-dependency of this association (prenatal caffeine consumption and birth size) as part of the Japan Environment and Children's Study. Methods: A prospective birth cohort included 94 876 fetuses in Japan. Participants were enrolled between January 2011 and March 2014. Adjusted multiple linear regression and Cox regression models were used to examine the association between prenatal caffeine levels and infant birth size. Results: The median estimated caffeine consumption during pregnancy was 125.5 mg/day, as determined by self-administered questionnaires. There were 7252 SGA infants (7.6%) and 4281 preterm birth infants (4.5%). Compared with infants of mothers whose caffeine consumption during pregnancy was in the lowest quartile (4.2 to <86.4 mg/day), infants of mothers whose caffeine consumption was in the highest quartile 4 (205.5-5080.0 mg/day) were at an increased risk of SGA (relative risk [RR] 1.18, 95% confidence interval [CI] 1.10, 1.27), and at an increased risk of preterm birth at the second trimester of gestation (RR 1.94, 95% CI 1.12, 3.37), with a 0.32-day reduction in gestational age (95% CI −0.52, −0.12) and with a 0.07 reduction in birthweight Z-score observed (95% CI −0.09, −0.05). Conclusions: Prenatal caffeine consumption was associated with birth size. However, as the association between prenatal caffeine consumption and birth size was likely confounded by unpredicted potential factors, our confidence in the true causality of the association is moderate.

BACKGROUND: Manganese (Mn) is both an essential element and a potential toxicant. Although a few studies have suggested a nonlinear relationship between the maternal whole blood Mn level at delivery and infant birth weight, little is known about the effects of Mn levels during pregnancy on fetal growth, particularly with regard to sex-specific differences. METHODS: In this nationwide birth cohort study, we examined the association of maternal blood Mn level during pregnancy with infant birth weight, length, and head circumference in 16,473 mother-infant pairs. Pregnant women living in 15 regions across Japan were recruited between January 2011 and March 2014. The analysis of birth size (8,484 males and 7,989 females) was conducted using a nonlinear spline, followed by the use of quadratic regression or linear regression models. The analysis of small-for-gestational-age (SGA) (6,962 males and 6,528 females born vaginally) was conducted using multivariate logistic regression. Additionally, subgroup analysis was conducted according to the timing of blood sampling. RESULTS: The median maternal blood Mn level during pregnancy (i.e., 2nd and 3rd trimesters) was 16.2 µg/L (range, 4.3-44.5 µg/L). A positive linear association between the log blood Mn level and head circumference was observed in both male and female infants. However, a nonlinear relationship between the log blood Mn level and birth weight was observed only in male infants, such that the birth weight increased up to a blood Mn level of 18.6 µg/L. In the subgroup analysis stratified by the timing of maternal blood sampling, this nonlinear relationship was obvious only when sampling was performed in the 3rd trimester. Male infants in the lowest blood Mn level quartile (≤ 13.2 µg/L) faced an increased risk of SGA (odds ratio [95% confidence interval] = 1.35 [1.04-1.74]), as did those in the highest blood Mn level quartile (≥ 21.0 µg/L) when sampling was performed during the 3rd trimester (odds ratio [95% confidence interval] = 1.62 [1.10 to 2.39]), compared to those in the third blood Mn level quartile (the category including 18.6 µg/L). No association of blood Mn level with birth weight was observed among female infants, and blood Mn level was not associated with birth length in either male or female infants. CONCLUSION: A low blood Mn level during pregnancy or a high blood Mn level during the 3rd trimester was associated with a lower birth weight and increased risk of SGA in male infants, but not in female infants. A low blood Mn level was found to correlate slightly with a small head circumference among infants of both sexes.

Smoking during pregnancy is a risk factor for various adverse birth outcomes but lowers the risk of preeclampsia. Cardiovascular adaptations might underlie these associations. We examined the association of maternal smoking with the risk of hypertensive disorders of pregnancy (HDP) in a low-risk population-based cohort of 76,303 pregnant women. This study was a part of the Japan Environment and Children's Study. Smoking status was assessed using questionnaires completed by participants. Information about HDP was assessed using questionnaires completed by doctors. Compared with that for women who did not smoke, women who continued smoking >10 cigarettes per day during pregnancy had a significantly higher risk of developing HDP (odds ratio: 1.58, 95% confidence interval: 1.11-2.25). In multivariate analyses with adjustment for possible confounding factors, the association still remained (odds ratio: 1.51, 95% confidence interval: 1.04-2.19). When we regarded the number of cigarettes as a continuous variable, there was a linear association between the number of cigarettes and risk of HDP, with an odds ratio of 1.02 per cigarette per day (95% confidence interval: 1.00-1.04). Smoking a greater number of cigarettes was associated with a higher risk of HDP after adjustment for possible confounding factors. Cigarette smoking cessation may avoid the complications of HDP. Our findings suggest that, in addition to the risk of small-for-gestational-age children, an increased risk of HDP should be considered in the management of pregnant women who smoke cigarettes.

Background Since venous thromboembolism (VTE) is one of the causes of maternal mortality, several guidelines recommend prophylaxis using low molecular weight heparin for women in high-risk groups. The number of large population-based studies examining predictors for VTE has been limited, and there has been no study based on a Japanese population.Objective Our objective was to examine VTE risk factor during the pregnancy and post-partum period.Materials and Methods A nationwide birth cohort study known as the 'Japan Environment and Children's Study (JECS)' was conducted by the Ministry of the Environment. The subjects consisted of 103,070 pregnancies recruited by the JECS between January 2011 and March 2014. Pregnant women completed the questionnaires during the first and second/third trimester. Their medical records were transcribed by physicians or research coordinators at registration, just after delivery and at 1 month after delivery.Results The frequency of VTE was 7.5 per 10,000 pregnancies (77 of 103,070) during the pregnancy and post-partum period. After the adjustment of multiple covariates for each factor, endometriosis and recurrent pregnancy loss (RPL) were identified as novel independent risk factors for VTE. Adjusted odds ratios were as follows: 2.70 (95% confidence interval, 1.21-6.00) for endometriosis and 6.13 (2.48-15.16) for RPL. Threatened abortion, threatened pre-term birth, pre-term birth and caesarean section were ascertained to be risk factors for VTE.Conclusion Careful attention should be given to novel predictors, such as endometriosis and a history of RPL, to prevent VTE during the pregnancy and postpartum period.

Background: It is necessary to determine whether there are adverse health effects of prenatal exposure to long-term, low levels of mercury and selenium. However, there are limited that reports on the association between mercury levels by selenium levels and birth size. Therefore, we examined whether maternal mercury levels during pregnancy had any effect on infant birth size, and size, and whether selenium levels influenced this relationship.Objectives: To examine the association between mercury and selenium levels during pregnancy with infant birth size.Methods: The Japan Environment and Children's Study is a prospective birth cohort conducted between 2011 and 2014. Total mercury levels and total selenium levels in maternal blood during the second and third tri-mesters were measured using Inductively Coupled Plasma-Mass Spectrometry. Birth weight and small-for-gestational-age were confirmed by medical records. Small-for-gestational-age was defined as birth weight below the 10th percentile according to standard percentile for gender, parity, and gestational age. Multiple linear and logistic regression analyses were used to examine the association between maternal mercury exposure and birth weight or small-for-gestational-age adjusted for confounders (including maternal age and body mass index pregnancy).Results: Overall, 15,444 pregnant women were included in this study. Median (inter-quartile range) of blood mercury and selenium levels were 3.66 (2.59-5.18) ng/g and 170.0 (158.0-183.0) ng/g, respectively. Compared to infants of mothers with the highest blood selenium level, those of mothers with the lowest blood selenium level had neither a significant birth weight increase (9 g, 95% confidence interval: -6, 25) nor a significant odds ratio for small-for-gestational-age (0.903, 95% confidence interval: 0.748, 1.089). Compared to infants of mothers with the lowest blood mercury level, those of mothers with the highest blood mercury level had neither a significant birth weight reduction (-12 g, 95% confidence interval: -27, 4) nor a significant odds ratio for small-for-gestational-age (0.951, 95% confidence interval: 0.786, 1.150). Compared to infants of mothers with the lowest quartile of maternal blood mercury level, all infants of mothers with the highest quartile of maternal blood mercury level had a reduced birth head circumference of 0.073 cm (95% confidence interval: -0.134, -0.011).Conclusions: There was no association between maternal blood mercury levels and small-for-gestational-age and birth weight among 15,444 pregnant women. In a Japanese population, which has a relatively higher blood mercury level than reported in Western population, reduced birth size was not found to be associated with blood mercury levels, with the exception of birth head circumference.

© 2018, Japanese Society of Sleep Research. Pregnant women have more sleep problems compared to non-pregnant women. Our objective was to investigate the differences in sleep patterns by age among Japanese women enrolled in the Japan Environment and Children’s Study during preconception and pregnancy. Questionnaires on sleep status were administered to pregnant women twice in the first, second and/or third trimesters. Wake-up time, bedtime, sleep duration and quality of sleep were analyzed in 103,099 respondents. Women younger than 20 years of age awoke and slept the latest in comparison to all other age groups during preconception and pregnancy. Sleep time of women younger than 20 years of age was the longest in comparison to other age groups. The wake-up time and bedtime of teenage mothers were delayed from preconception to second or third trimester, but they did not display any statistically significant changes in other age groups. Moreover, the younger the pregnant women were the more sleep trouble they had despite reportedly being tired, and felt more sleep-deprived despite having had enough sleep time in both second and third trimesters. The sleep state of pregnant women differed by age, with younger women experiencing more sleep trouble and feeling less rested compared to other groups. In future studies, the influences of sleep during pregnancy on the health and development of the children of these pregnant women will be clarified.

© 2018 North American Society for Pediatric and Adolescent Gynecology Study Objective: Few studies have investigated the risky health behaviors and psychosocial characteristics of teenage mothers in countries with a low teenage birth rate, like Japan. We examined the differences in maternal prenatal risky health behaviors and psychosocial characteristics, and birth weight of infants between teenage and adult mothers. Design, Setting, Participants, Interventions, and Main Outcome Measures: We identified 1159 teenage (age younger than 20 years) and 73,547 adult mothers (20-34 years) who participated a nationwide birth cohort study between 2011 and 2014. Behavioral and psychosocial characteristics were ascertained using questionnaires during pregnancy. Birth weight of infants was verified through medical records. Univariate and multivariable logistic regression were used to assess the association of teenage motherhood and birth weight of infants with parity, marital status, household income, maternal education, job status, preconception body mass index, gestational weight gain, psychological distress, and smoking status. Results: Teenage mothers were significantly more likely to smoke and have psychological distress and less likely to use alcohol than adult mothers (9.9% vs 4.6%, P < .001; 8.9% vs 3.4%, P < .001; 1.3% vs 2.5%, P < .001, respectively). No association was found between teenage motherhood and low birth weight in infants (odds ratio 0.99; 95% confidence interval, 0.73-1.32). Further, no association was found after adjusting for covariates. Conclusion: A substantially greater number of Japanese teenage mothers smoked and experienced severe psychological distress than adult mothers. Our findings will be useful for future research and for developing effective policies and programs for teenage mothers and their children.

© 2018 The Authors The results of several epidemiological studies have shown a moderate association between postpartum depression (PPD) and mother-infant bonding (MIB); however, associations and changes that longitudinally considered parity were not reported. We investigated the possible association between PPD and MIB at one month after birth, in addition, the changes of these indices by parity. From a dataset comprising 103,099 maternal registrations in The Japan Environment and Children's Study, the present study analyzed complete data on questionnaires for 76,363 women who participated once (cross-sectional group) and 3753 women who participated twice (follow-up subgroup). Edinburgh Postnatal Depression Scale (EPDS) scores and the Mother-to-Infant Bonding Scale-Japan (MIBS-J) scores were obtained one month after delivery. We identified the two factors of the MIBS-J, “lack of maternal feeling (LMF)” and “anxiety about caregiving (AC)” through confirmatory factor analysis. Associations between total EPDS and each factor of MIBS-J were evaluated using multiple regression analyses after adjusting for potential confounders. Total EPDS and both factors (LMF and AC) were positively related in the cross-sectional group (fully adjusted β = 0.26 and 0.39 for LMF and AC, respectively), in the follow-up subgroup at first participation (0.24 and 0.40, respectively) and at the second participation (0.25 and 0.39, respectively). Multiple regression analyses revealed a robust, moderate relationship between postpartum depression and mother-infant bonding. PPD and MIB scores were shown to decrease from the first child to the second in the follow-up subgroup. Consequently, interventions which would increase a mother's child care experience and expertise would prevent PPD and improve MIB.

© 2018, Springer-Verlag GmbH Germany, part of Springer Nature. Purpose: To examine the association between elevated blood cadmium (Cd) and lead (Pb) concentrations and increased risk of gestational diabetes mellitus (GDM). Methods: This cross-sectional study included pregnant women (n = 16,955) enrolled in the Japan Environment and Children’s Study. Concentrations of Cd and Pb in blood samples collected at 22–28 weeks’ gestation were measured by inductively coupled plasma mass spectrometry. GDM was diagnosed according to the 2011 Japan Society of Obstetrics and Gynecology and Japan Association of Obstetricians and Gynecologists criteria. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were estimated using logistic regression analysis. Results: Blood Cd and Pb concentrations were slightly higher among women with GDM than among those without GDM; however, these differences were not statistically significant. Elevated blood Cd and Pb concentrations were not associated with increased GDM risk in the nulliparous group (Cd OR 0.76; 95% CI 0.28–2.08 for high vs low category; Pb OR 2.51; 95% CI 0.72–8.72) or the parous group (Cd OR 0.64; 95% CI 0.29–1.44; Pb OR 0.31; 95% CI 0.04–2.29). Conclusions: This study demonstrates that Cd and Pb exposure, in the range of blood levels observed, has no significant relationship with the development of GDM. Further prospective studies would be valuable to confirm these findings.

Background: Dysmenorrhea influences emotional distress as well as physical suffering in young non-pregnant women. The aim of this study was to assess the potential association between preconception dysmenorrhea and the development of psychological distress during pregnancy.Methods: This study was a part of the Japan Environment and Children's Study (JECS), a nationwide birth cohort study conducted between 2011 and 2014 in Japan. A total of 87,102 pregnant Japanese women with no psychological distress (Kessler 6-item psychological distress scale [K6] score <= 12) in early pregnancy were eligible. Among these, 7626 had mild and 1638 had severe preconception dysmenorrhea. The prevalence and risk of maternal psychological distress (K6 scores <= 13) in the second or third trimester were compared among preconception dysmenorrhea severity groups.Results: A higher percentage of women with mild (2.6%) or severe preconception dysmenorrhea (3.6%) suffered psychological distress during pregnancy compared to that in women without dysmenorrhea (2.1%). A multilevel logistic regression model, adjusting for baseline characteristics and the K6 score at enrollment, showed that the severity of dysmenorrhea was associated with psychological distress (mild dysmenorrhea: adjusted odds ratio [aOR], 1.154; 95% confidence interval [95% CI], 0.980-1.359; and severe dysmenorrhea: aOR, 1.457; 95% CI, 1.087-1.951).Limitations: Information about dysmenorrhea was obtained during early pregnancy. The JECS did not have clear diagnostic criteria for dysmenorrhea.Conclusions: Preconception dysmenorrhea is associated with an elevated incidence of psychological distress during pregnancy. Additionally, expectant mothers with a history of severe dysmenorrhea symptoms before pregnancy have a higher risk of developing psychological distress.

BackgroundAlthough pregnancies conceived by assisted reproductive technology (ART) have a higher risk of maternal/perinatal complications, the overall risk of adverse outcomes necessitating advanced obstetric care has not been closely examined. The present study aimed to assess and compare the risk of maternal/perinatal complications and adverse outcomes in pregnancy and childbirth conceived by ART with those conceived naturally.MethodsThis study was conducted as a part of the Japan environment and children's study (JECS), an ongoing nationwide birth cohort study in Japan. The risk of maternal/perinatal complications and adverse outcomes was assessed by mode of conception (natural conception, ovulation induction [OI] without ART, conventional in vitro fertilization and embryo transfer [IVF-ET], or intracytoplasmic sperm injection [ICSI]) using logistic regression and generalized estimating equations controlling for potential confounders.ResultsThe final dataset included women who conceived naturally (N=90,506), by OI without ART (N=3939), by conventional IVF-ET (N=1476), and by ICSI (N=1671). Compared with women who conceived naturally, those who conceived by conventional IVF-ET were at higher risk of placenta previa (adjusted OR 2.90 [95% CI 1.94, 4.34]), morbidly adherent placenta (6.85 [3.88, 12.13]), and pregnancy-induced hypertension (1.40 [1.10, 1.78]) whereas those who conceived by ICSI had a higher risk of placental abruption (2.16 [1.20, 3.88]) as well as placenta previa (2.01 [1.29, 3.13]) and morbidly adherent placenta (7.81 [4.56, 13.38]). Women who conceived by ART had a higher risk of blood transfusion (conventional IVF-ET: 3.85 [2.52, 5.88]; ICSI: 3.76 [2.49, 5.66]) and ICU admission (conventional IVF-ET: 2.58 [1.11, 6.01]; ICSI: 3.45 [1.68, 7.06]) even after controlling for potential confounders. Neonates conceived by ART had a higher risk of preterm birth (conventional IVF-ET: 1.42 [1.13, 1.78]; ICSI: 1.31 [1.05, 1.64]).ConclusionsWomen who conceived by ART had a higher risk of maternal/perinatal complications necessitating advanced obstetric care. Obstetricians should be aware of the increased risk of adverse outcomes among this population.

Current evidence suggests that the aetiology of congenital gastrointestinal (GI) tract atresia is multifactorial, and not based solely on genetic factors. However, there are no established modifiable risk factors for congenital GI tract atresia. We used data from a Japanese nationwide birth cohort study launched in 2011, and examined whether fish consumption in early pregnancy was associated with congenital GI tract atresia. We analysed data of 89 495 women (mean age at delivery = 31.2 years) who delivered singleton live births without chromosomal anomalies. Based on the results of the FFQ, we estimated the daily intake of fish and n-3 PUFA consumption in early pregnancy. We defined a composite outcome (oesophageal atresia, duodenal atresia, jejunoileal atresia and/or anorectal malformation) as congenital GI tract atresia. In this population, median fish intake was 31.9 g/d, and seventy-four cases of congenital GI tract atresia were identified. Fish consumption in early pregnancy was inversely associated with the composite outcome (multivariable-adjusted OR for the high v. low consumption category = 0.5, 95% CI 0.3, 1.0). For all the specific types of atresia, decreased OR were observed in the high consumption category, although not statistically significant. Reduced atresia occurrence was observed even beyond the US Food and Drug Administration's recommended consumption of no more than 340 g/week. Also, n-3 PUFA-rich fish and n-3 PUFA consumptions tended to be inversely associated with atresia. Fish consumption in early pregnancy may be a preventive factor for congenital GI tract atresia.

© 2018 Hidetoshi Mezawa et al. Background: The aims of the present report were to estimate the prevalence of congenital anomalies (CAs) among infants in Japan using data from the Japan Environment and Children’s Study (JECS) and to evaluate the validity of CA classification within JECS. Methods: Data on CAs were collected at delivery and at age 1 month from the medical records of 101,825 infants at 15 regional centers. The analyses focused on 61 CAs, selected on the basis of reported associations with environmental exposure. Prevalence per 10,000 pregnancies (including miscarriages, stillbirths, and live births) was stratified according to four reporting patterns (at delivery, at age 1 month, at either, and at both). To evaluate the accuracy of observed CA prevalence, the medical records of 179 cases from a single JECS regional center underwent independent, retrospective re-evaluation. Results: The prevalence of major CAs in four reporting patterns (at delivery, at age 1 month, at either, and at both) was 2.4, 2.6, 3.5, and 1.4 for myelomeningocele=spina bifida; 4.3, 4.2, 5.3, and 3.2 for cleft palate; 18.1, 17.4, 19.5, and 15.1 for cleft lip with or without cleft palate; 73.4, 100.3, 120.8, and 52.8 for congenital heart disease; and 10.5, 14.1, 15.0, and 9.6 for Down’s syndrome, respectively. In the subsample re-evaluation, CA diagnoses were confirmed for 92.7%, 93.3%, 90.5%, and 97.8% of cases in the four reporting patterns (at delivery, at age 1 month, at either, and at both), respectively. Conclusions: The present report generated reliable data concerning the prevalence of major CAs in JECS.

© 2018 The Author(s). Background: Few studies have examined the association of workhours and shift work (referred to here as "time-related work factors") with dietary behaviors. We aimed to investigate this association, as well as the dietary behaviors among individuals with occupations characterized by time-related work factors. Methods: A cross-sectional study was performed using data from the Japan Environment and Children's Study. The study included 39,315 working men. Dietary behaviors (i.e., skipping breakfast, eating out, eating instant food, overeating, and eating fast) were assessed with a self-reported information from the Food Frequency Questionnaire. Logistic regression analysis was conducted to examine the associations of time-related work factors with dietary behaviors and dietary behavior tendencies among those in occupations characterized by long workhours and/or shift work. Results: Long workhours were associated with high frequencies of skipping breakfast, eating out, eating instant food, overeating, and eating fast. The frequency of having shift work was associated with high frequencies of skipping breakfast, eating out, and eating instant food. Several occupations involving long workhours and/or shift work showed specific dietary behaviors; in some occupations, the level of significance changed after adjusting for time-related work factors in addition to other potential confounding factors. Conclusions: Time-related work factors may help explain workers' dietary behaviors. Long workhours and shift work may lead to poor dietary behaviors. Other factors influenced by occupation itself, such as food environment, may also influence workers' dietary behaviors. Workhours and/or shift work, and these other work factors, should be given attention in workplace health promotion.

© 2018 The Author(s). Objective: There have been increasing reports on the association between cesarean section (C-section) and the subsequent development of diseases in infants. C-section affects the diversity of microbiota in the infant's gut. In the present study, we investigated the association between infants delivered by C-section and the development of constipation at 1 year old due to altered gut microbiota using data from the Japan Environment and Children's Study (JECS). Results: This cohort study (n = 83,019) used data from JECS, an ongoing cohort study which began in January 2011. Data on bowel movement and potential confounding factors were recorded. A log-binomial regression model was used to estimate the risk of C-section, and the results were expressed as risk ratios and their respective 95% confidence intervals. Although infants delivered by C-section were of significantly younger gestational age and lesser birth weight than vaginally delivered infants, the frequency of bowel movements was almost similar between the two, independent of the mode of delivery. The prevalence of constipation in the entire infant was 1.37%. No significant differences were observed for C-section in crude and adjusted risk ratios for constipation.

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 91637 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 66) 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.

© 2018 Elsevier Ltd There are many psychosocial and biomedical risk factors for postpartum depression (PPD). However, associations between co-resident family members and PPD risk have not been examined. This study investigated whether co-resident family members were associated with risk for PPD during 1 month postpartum among Japanese women, and if these associations were modified by household income and their perceived partner's involvement in childcare. The sample comprised 86,490 women. Data were drawn from the Japan Environment and Children's Study, a large-scale national cohort study started in 2011. Our major predictor was co-resident family members when they registered around the first trimester of the women's pregnancy: partner, parent(s), parent(s)-in-law, or child(ren). The outcome was PPD at 1 month after delivery, assessed by the Edinburgh Postnatal Depression Scale. Adjusted odds ratios (OR) for family members and PPD incidence were calculated using multivariable logistic regression analysis. Subgroup analyses were conducted by household income and perceived partner's involvement in childcare. Adjusted ORs (95% confidence interval) for PPD for those not living with their partner, parent(s), parent(s)-in-law, or child(ren) compared with those who lived with these family members were 1.21 (1.07–1.37), 1.13 (1.03–1.24), 0.91 (0.84–0.98), and 1.42 (1.31–1.53), respectively. The level of perceived partner's involvement in childcare changed the identified association between family member and PPD. We found that “who a pregnant woman lives with” affects the risk of PPD in the first month postpartum, and high levels of perceived partner's involvement in childcare reduced harmful effects/increased protective effect of family members on PPD incidence. These findings suggested that interventions to increase perceived partner's support for childcare may be effective in preventing PPD, regardless of living situation.

© 2018 Elsevier Inc. Background: Heavy metals are widely distributed in the environment. Recent reports have demonstrated the risk of preterm birth following heavy metal exposure. Preterm births are classified as early and late, depending on the duration of pregnancy, and are associated with increased risk of congenital illnesses such as heart failure, asthma, etc. Particularly, early preterm births carry a higher risk of mortality; however, the differential effects of heavy metal exposure on early and late preterm births are unknown. Objectives: To analyze the association between maternal whole blood concentrations of heavy metals, such as cadmium (Cd), lead (Pb), mercury (Hg), selenium (Se), and manganese (Mn) that are common toxicants in Japan, and early and late preterm births. Methods: The data of 14,847 pregnant women who were participants of the Japan Environment and Children's Study were used. Data of the self-questionnaire pertaining to the first trimester (T1), second/third trimester (T2), and medical records after delivery were analyzed. We divided preterm birth into two groups: early preterm (22 to < 34 weeks) and late preterm (34 to < 37 weeks). Maternal blood samples for measuring heavy metal concentrations were collected in T2 (pregnancy weeks: 14–39). The participants were classified into four quartiles (Q1–Q4) according to increasing heavy metal levels. Results: The rate of preterm birth was 4.5%. After controlling for confounding factors, such as age, pre-pregnancy body mass index, smoking, partner's smoking, drinking habits, gravidity, parity, number of cesarean deliveries, uterine infections, household income, educational levels, and sex of infant, Cd levels were found, by multivariable logistic regression analysis, to be significantly associated with early preterm birth (p = 0.002), with odds ratio for early preterm birth of 1.91 (95% confidence interval: 1.12–3.27, P = 0.018) in subjects of Q4 compared with in subjects with term birth (≧ 37 weeks). Conclusion: Maternal blood Cd levels during pregnancy are positively associated with the risk of early preterm birth among Japanese women. Identification of the main source of maternal Cd exposure may contribute to the prevention of early preterm births and health maintenance of mothers and their infants in the future.

INTRODUCTION: An abnormal distal insertion of the extensor pollicis brevis (EPB) tendon into the thumb interphalangeal joint (IP) has been observed in refractory cases of de Quervain's disease. This is associated with the extensor being wider at the midpoint of the proximal phalanx; however, there is no method to noninvasively measure this. This study evaluated the accuracy of measuring the extensor width using ultrasonography, to establish a noninvasive method for predicting an EPB extending the IP insertion. MATERIALS AND METHODS: Of 23 arms from 12 fresh frozen cadavers, the extensor tendon width at the midpoint of the proximal phalanx was measured using ultrasonography and directly at dissection. The association between these values was evaluated using correlation analysis. A cut-off value of extensor tendon width was obtained using receiver operating characteristic analysis. RESULTS: A strong correlation was observed between the ultrasonography and the measured values. The EPB tendons were normal in 13 arms (57%) and extended in 10 (43%), with a significant difference between these groups in the mean width of the extensor tendon (6.8 ± 1.1 vs. 8.4 ± 1.0 mm). A cut-off extensor tendon width of 8.0 mm yielded an EPB extending the IP. CONCLUSION: An EPB extending the IP tendon can be predicted by measuring the extensor tendon width at the midpoint of the proximal phalanx using ultrasonography. The cut-off tendon width value of ≥ 8.0 mm may be useful for assessments prior to surgery and for conservative care.

The prevention of sick building syndrome necessitates the design and construction of buildings that can maintain low concentrations of Volatile Organic Compounds (VOCs). This study aims to determine whether VOC concentrations in a new commercial bank can be reduced through the selection of building materials and monitoring of construction processes. The building was designed and constructed with close attention to the selection of architectural materials and supervision of construction. Twice during construction, indoor air samples were collected and their chemical compositions determined. The Ministry of Health, Labour, and Welfare of Japan (MHLW) guideline concentrations for VOCs were not exceeded for any of the specified chemicals, including toluene, xylem, ethylbenzene, styrene, p-dichlorobenzene, tetradecane, formaldehyde, and acetaldehyde. After construction, the total VOC concentration was 104 mu g/m(3). This value is substantially lower than the target value of 400 mu g/m(3) recommended by the MHLW. Construction of a bank building with low concentrations of indoor chemical substances can be achieved through the proper selection of architectural materials and construction site supervision.

© 2018 The Author(s). Background: Nausea and vomiting during pregnancy (NVP) is considered to be associated with favorable fetal outcomes, such as a decreased risk for spontaneous abortion. However, the relationship between NVP and preterm births remains unknown. This study was conducted to evaluate the association between NVP and the risk of preterm births. Methods: The dataset of a birth cohort study, the Japan Environment and Children's Study (JECS), was retrospectively reviewed. Participants' experience of NVP prior to 12 gestational weeks were evaluated by a questionnaire administered from 22 weeks of pregnancy to 1 month before delivery. NVP responses were elicited against four choices based on which the study population was divided into four subcohorts. Preterm birth was the main study outcome. Logistic regression analysis was used to quantify an association between NVP and risk of preterm birth. Results: Of 96,056 women, 79,460 (82.7%) experienced some symptoms of NVP and 10,518 (10.9%) experienced severe NVP. Compared to those who did not experience NVP, women with severe NVP had lower odds for preterm birth [adjusted odds ratio (aOR) 0.84, 95% confidence interval (95% CI) 0.74-0.95]. An even lower OR was found among very preterm birth and extremely preterm birth (aOR 0.44, 95% CI 0.29-0.65). Conclusion: An inverse association exists between NVP and preterm births, especially, very preterm births and extremely preterm births.

© 2018 by the authors. Licensee MDPI, Basel, Switzerland. Studies examining workers’ diet according to smaller occupational groups within “large occupational categories” are sparse. The aim of this study was to examine the potential differences in workers’ diets based on the classification of workers into smaller occupational groups that comprise “large occupational categories”. The subjects of this study were working fathers who had participated in the Japan Environment and Children’s Study (N = 38,656). Energy and nutrient intake were calculated based on data collected from the Food Frequency Questionnaire. Occupations were classified according to the Japanese Standard Occupational Classification. Logistic regression analyses were performed to examine the adherence to current dietary recommendations within smaller occupational groups. In particular, significant differences were observed among the categorical groups of “professional and engineering workers”, “service workers”, and “agricultural, forestry, and fishery workers”. In “professional and engineering workers”, teachers showed higher odds of adherence to calcium intake recommendations compared with nurses (OR, 2.54; 95% CI, 2.02–3.14; p &lt; 0.001). In “agricultural, forestry, and fishery workers”, agriculture workers showed higher odds of adherence to calcium (OR, 2.15; 95% CI, 1.46–3.15; p &lt; 0.001) and vitamin C (OR 1.90, 95% CI 1.31–2.74, p = 0.001) intake recommendations compared with forestry and fishery workers. These findings may be beneficial from a research perspective as well as in the development of more effective techniques to improve workers’ diet and health.

The 7th Study Tour to International Organizations in Geneva was held by the Center for Preventive Medical Sciences, Chiba University from 25th to 27th September 2017. This is a training program which is open not only medical students but also all the graduate students of Chiba University. In this program, we have learned the role of several international organizations such as the World Health Organization (WHO), the Global Fund, International Federation of Red Cross and Red Crescent Societies(IFRC) and International Labor Organization (ILO). We also visited the Permanent Mission of Japan to the International Organizations in Geneva and discussed with officers and staffs of various international organizations. The participated students had an opportunity to deeply understand a range of global issues through lectures and discussions.