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.

The effects of prenatal exposure to household pesticides on fetal and neonatal growth have not been fully clarified. The present study aims to determine the effects of prenatal exposure to pesticides on neonates’ body size and growth during the first month. This study included 93,718 pairs of pregnant women and their children from the Japan Environment and Children’s Study. Participants completed self-reporting questionnaires during their second or third trimesters on their demographic characteristics and frequency of pesticide use during pregnancy. Child weight, length, and sex were obtained from medical record transcripts. Birth weight and length, as well as weight and length changes over the first month, were estimated using an analysis of covariance. Frequency of exposure to almost all pesticides had no effects on birth weight and length. However, we found small but significant associations (i) between the use of fumigation insecticides and decreased birth weight, and (ii) between frequencies of exposure to pyrethroid pesticides, especially mosquito coils/mats, and suppression of neonatal length growth. Prenatal exposure to household pesticides, especially those containing pyrethroids, might adversely influence fetal and postnatal growth trajectories.

Ready-meal consumption is increasing worldwide; however, its impact on human health remains unclear. We aimed to examine the association between processed food and beverage consumption during pregnancy and pregnancy outcomes. Pregnant women were recruited for the Japan Environment and Children’s Study (JECS), a nationwide, large-scale, prospective cohort study. This study included 104,102 registered children (including fetuses or embryos) and collected questionnaire-based data during the first and second/third trimester of pregnancy. Participants’ medical records were transcribed at pregnancy registration, immediately after delivery, and 1 month after delivery. Logistic regression analysis was used to estimate the association between processed food consumption and pregnancy outcomes. The incidence of stillbirth was higher in the group that consumed moderate (1–2 times per week) and high (≥3–7 times per week) amounts of ready-meals (adjusted odds ratio (aOR) = 2.054, 95% confidence interval (CI): 1.442–2.926, q = 0.002; aOR = 2.632, 95% CI: 1.507–4.597, q = 0.007, respectively) or frozen meals (aOR = 2.225, 95% CI: 1.679–2.949, q < 0.001; aOR = 2.170, 95% CI: 1.418–3.322, q = 0.005, respectively) than in the group that rarely consumed such foods. Processed food consumption during pregnancy should be carefully considered.

Maternal exposure to bisphenols, including bisphenol A (BPA), reportedly results in adverse pregnancy and offspring health outcomes. However, large birth cohort studies on the risk of BPA exposure during pregnancy remain limited. Here, we examined bisphenols' effects on adverse pregnancy and neonatal outcomes using data from the Japan Environment and Children's Study, a nationwide birth cohort study. We selected 4523 women with pregnancies resulting in singleton live births. First-trimester urine concentrations of bisphenols A, F, S, and AF were determined via high-performance liquid chromatography-tandem mass spectrometry. We analyzed the association between BPA exposure and preterm birth, hypertensive disorders of pregnancy, gestational diabetes mellitus, small- and large-for-gestational-age infants, low birth weight, offspring physical and chromosome abnormalities using Bayesian logistic regression analysis after applying the GSimp imputation method for concentrations within the minimum reporting limit. Bisphenol detection rates were generally low (0.0-11.9 % of samples), except for that of BPA (71.5 %), and BPA concentrations were lower than those reported in previous international studies. The estimated BPA daily intake for 86.6 % of the study participants exceeded the European Food Safety Authority's tolerable daily intake (0.0002 µg/kg/day). However, BPA intake was not significantly associated with any outcome. These findings suggest that BPA's current exposure levels do not affect measured pregnancy and neonate outcomes in Japan. Here, although BPA levels reflect only recent exposure, the potential health risks associated with BPA underscore the need for further research to investigate the long-term effects of low-level exposure on maternal and child health.

To discuss appropriate physical activity (PA) levels during pregnancy, this prospective cohort study examined the relationships between PA levels before and during pregnancy and physical and mental health status. Fixed data for 104,102 pregnant women were used from the Japan Environment and Children’s Study, of which data for 82,919 women were analyzed after excluding women with multiple birth and pregnancy complications. PA levels were measured using the International Physical Activity Questionnaire-Short Form. The 8-Item Short Form Health Survey was used to measure outcomes. Logistic regression with multiple imputations showed that moderate PA for over 720 min/wk and vigorous PA before pregnancy were associated with poorer mental health in the first trimester (adjusted odds ratio (AOR): 1.087–1.376. Walking in the second and third trimesters was associated with better physical and mental health (AOR: 0.855–0.932). Moderate PA over 1080 min/wk and vigorous PA in the second and third trimesters were associated with poorer mental health (AOR: 1.223–1.873). Increases over 4135.4 MET–min/wk and decreases in PA levels were associated with poorer mental and physical health (AOR: 1.070–1.333). Namely, pregnant women receiving health benefits prefer continuous walking in addition to avoiding vigorous PA and excessive changes in PA levels during pregnancy.

Objectives: Musculoskeletal disorders (MSDs) among endoscopic assistants are a major occupational concern. While ergonomic interventions such as education and microbreaks have reduced MSDs in surgical settings, few studies have focused specifically on endoscopic assistants. This study evaluated the effectiveness of a brief stretching protocol, the one‐minute triple stretch (OMTS), in reducing MSD symptoms and improving posture. Methods: This crossover study of 10 endoscopic assistants from two hospitals used a repeated measures quasi‐experimental design. Participants were alternately assigned to a control group (standard procedures) or intervention group (OMTS every 20 min). Musculoskeletal discomfort was assessed using the Numerical Rating Scale. Work performance was evaluated via two standardized scales, and posture was analyzed using a motion tracking system. Data were collected at baseline, mid‐, and postprocedure. Results: The OMTS significantly reduced left shoulder discomfort at 120 min ( p = 0.02, Hedges' g = −0.79), exceeding the minimal clinically important difference (MCID = 1.5). Moderate, nonsignificant effects were observed in the neck and lower back. Neck flexion posture improved significantly in the OMTS group ( p = 0.03, g = −0.54), exceeding the MCID (2.9°). Conclusion: The OMTS appears to be a feasible ergonomic intervention that can reduce MSD symptoms in endoscopic assistants. Further multicenter studies are needed to confirm its effectiveness. Trial Registration: The study was registered in the UMIN Clinical Trials Registry (Registration Number: UMIN000048799) on August 31, 2022