Despite delayed childbearing for women in both high and low socio-economic
status(SES) in Korea since the economic crisis in the late 90s, more attention has been
drawn to women’s older age and biomedical characteristics than other socioeconomic,
behavioral, and psychological factors to predict preterm birth (PTB) or low birth weight
(LBW). Thus, this study aims to explore contributing factors in the prenatal period―health
care and stress, and psychosocial correlates of stress―to the SES differentials in PTB or
LBW among Korean women. We surveyed 951 women aged 30-44 years who had
delivered in the last three years. We estimated the odds ratios of PTB or LBW between
the SES groups adjusting for the following four categories of variables : (a) prenatal health
behaviors (e.g., regular hospital visits, folic acid supplementation, gestational increase in
body mass index, smoking, and regular meals) ; (b) prenatal stress (e.g., negative life
events, anxiety about fetal health, etc.) ; (c) psychosocial correlates of stress (e.g., anxiety
about fetal health, social support, and residential environment) ; (d) maternal medical
history and birth characteristics. Among Korea mothers, the SES gaps in preterm birth or
LBW were completely explained by the prenatal health behaviors and stress in prenatal
period with the biomedical characteristics for mothers and newborns held constant. PTB
or LBW births for Korean women in low-SES occupations could be prevented by
promoting their health behaviors and building stress-coping skills in the prenatal period.