Prenatal tobacco exposure and psychiatric outcomes in adolescence: is the effect mediated through birth weight?

OBJECTIVE: This study aims to examine the associations between prenatal exposure to maternal smoking, birth weight and persistent offspring psychiatric symptoms. Additionally, we aim to examine whether the relationship between prenatal maternal smoking and persistent offspring psychiatric symptoms is mediated by offspring birth weight. METHODS: This study used the Growing Up in Ireland (GUI) longitudinal cohort. The GUI is a nationally representative longitudinal study of children which consisted of three data collection waves, at ages 9, 13, and 17 years. Logistic regression analysis was used to examine associations between prenatal tobacco exposure, and offspring psychiatric symptoms. Linear regression was used to examine associations between prenatal tobacco exposure and offspring birth weight. We conducted a mediation analysis examining potential etiological pathways linking maternal smoking during pregnancy, offspring birth weight, and later offspring psychiatric symptoms. All analyses were adjusted for confounders including household income, maternal level of education, and family psychiatric history. Additionally, examination of birth weight and subsequent psychiatric symptoms also was controlled for prematurity. RESULTS: We found that the association between prenatal tobacco exposure and later psychiatric symptoms is mediated by birth weight. CONCLUSIONS: This work provides further evidence that maternal smoking during pregnancy is an important modifiable lifestyle factor that has an impact not just on the physical health of offspring but also their mental wellbeing. Supporting women with structured smoking cessation programs at the earliest stages of pregnancy should be a public health priority.

The association between subjective maternal stress during pregnancy and offspring clinically diagnosed psychiatric disorders.

OBJECTIVE: Exposure to prenatal stress is a ubiquitous and non-specific risk factor for adverse outcomes in adulthood. In this study, we examined associations between exposure to subjective maternal stress during pregnancy and subsequent diagnosis of psychiatric disorders in offspring. METHOD: This study used the Helsinki Longitudinal Temperament Cohort, a prospective birth cohort of individuals born between 1 July 1975 and 30 June 1976 in Helsinki, Finland. The sample for this study comprised 3626 infants whose mothers had completed health and well-being assessments during pregnancy which included a measure of self-reported stress. We ran logistic regressions to assess potential associations between prenatal stress and offspring psychiatric disorder in adulthood, identified through the Finnish Hospital Discharge Register. RESULTS: Individuals whose mothers reported stress during pregnancy had significantly greater odds of developing a psychiatric disorder (OR = 1.41, 95% CI = 1.10-1.81) particularly a mood disorder (OR = 1.67, 95% CI = 1.10-2.54). These associations remained after adjusting for parental psychiatric history, and other prenatal factors. CONCLUSIONS: Individuals exposed to prenatal stress had significantly increased risk of developing psychiatric disorders later in life. This finding highlights the importance of supporting the mental health and emotional well-being of women during pregnancy.