title: Effect of maternal job strain during pregnancy on infant neurodevelopment by gender at 6 and 12 months: Mothers and Children's Environmental Health (MOCEH) study.
abstract: OBJECTIVE
  Limited evidence is available regarding the association between prenatal job strain and infant neurodevelopment. Most studies used stress indicators other than job strain to explain the relationship between prenatal maternal stress and child development. The objective of this study was to investigate the association between maternal job strain during pregnancy and neurodevelopment in infancy.
  
  
  METHODS
  Mothers and Children's Environmental Health (MOCEH) study, an on-going prospective birth cohort study, has been conducted in South Korea since 2006. Job strain during pregnancy was measured using Korean version of Job Content Questionnaire (JCQ). Infant neurodevelopment was assessed using Korean Bayley Scale of Infant Development II (K-BSID-II) at 6 and 12 months of age. A total of 343 mother-child pairs that completed JCQ and K-BSID-II more than once were included. Mental Developmental Index (MDI) and Psychomotor Developmental Index (PDI) defined in the K-BSID-II were used as outcome variables.
  
  
  RESULTS
  Compared to infants from mothers with low job strain, significant (p < 0.05) decreases in PDI were found in infants from mothers with active and passive job at 6 months of age. After stratification by infant sex, boys in the high strain group had a lower MDI score than boys in the low job strain group at 12 months. On the other hand, girls in the high strain and active groups had higher MDI scores than girls in the low job strain group at 12 months. PDI at 12 months also showed different results by sex. Boys in the high strain and passive job groups had lower PDI scores than boys in the low job strain group. However, such difference was not observed in girls.
  
  
  CONCLUSIONS
  The findings of this study suggest that prenatal job strain affects infant neurodevelopment in a gender-dependent manner.
authors: Department of Preventive Medicine, Ewha Medical Research Center, Ewha Womans University, Seoul, South Korea.
authors: Eunjeong
authors: E
authors: Kim
authors: Department of Preventive Medicine, Ewha Medical Research Center, Ewha Womans University, Seoul, South Korea.
authors: HyeSook
authors: H
authors: Park
authors: Department of Preventive Medicine, College of Medicine, Seoul National University College of Medicine, Seoul, South Korea.
authors: Yun-Chul
authors: YC
authors: Hong
authors: Department of Preventive Medicine, College of Medicine, Dankook University, Cheonan, South Korea.
authors: Mina
authors: M
authors: Ha
authors: Department of Occupational and Environmental Medicine, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, South Korea.
authors: Yangho
authors: Y
authors: Kim
authors: Environmental Health Research Division, National Institute of Environmental Research, Incheon, South Korea.
authors: Bo-Eun
authors: BE
authors: Lee
authors: Department of Preventive Medicine, Ewha Medical Research Center, Ewha Womans University, Seoul, South Korea.
authors: Eun-Hee
authors: EH
authors: Ha
keywords: Cognition; Infant neurodevelopment; Job strain; Prenatal psychosocial stress