Association of prenatal maternal blood lead levels with birth outcomes in the Japan Environment and Children's Study (JECS): a nationwide birth cohort study.

Background: Despite dramatic declines in prenatal maternal blood lead levels (BLLs) in most developed countries, little is known about the effects of extremely low-level (<1.0 µg/dL) lead exposure on fetal growth.

Methods: We measured maternal BLL during the second or third trimester of pregnancy and assessed birth outcomes, including birthweight, preterm birth (<37 gestational weeks) risk, small for gestational age births (SGA; birthweight <10th percentile) and low birthweight (LBW; <2500 g).

Loneliness among mothers raising children under the age of 3 years and predictors with special reference to the use of SNS: a community-based cross-sectional study.

Background: Loneliness in mothers raising children can adversely impact the health of their children and lead to child abuse, depression, and deterioration of mothers' health. Few studies to date have specifically assessed the association between loneliness and social factors, including the use of social network sites (SNSs), and personal factors. This study aimed to identify predictors of loneliness in mothers raising children, with special reference to SNS use.

[Awareness survey of Healthcare Number System pros and cons according to medical doctors in Japan].

Objectives: After bills to launch the Social Security and Tax Number System were enacted in 2013, health and political officials have considered the Healthcare Number System (the System). However, little is known about doctors' awareness and concerns about the System. This study aimed to measure how many doctors disagree with the System, examine the doctors' characteristics, and analyze the benefits and harms of the System that they identified.