Maternal Stressful Life Events Prior to Conception and the Impact on Infant Birth Weight in the United States

Abstract

Objectives We sought to determine if and to what extent a woman’s exposure to stressful life events prior to conception (PSLEs) were associated with subsequent infant birth weight by using a nationally representative sample of US women. Methods We examined 9350 mothers and infants participating in the first wave of the Early Childhood Longitudinal Study-Birth Cohort in 2001. Weighted regressions estimated the effect of exposure on very low and low birth weight, adjusting for maternal sociodemographic and health factors and stress during pregnancy. Results Twenty percent of women experienced any PSLE. In adjusted analyses, exposed women were 38% more likely to have a very low birth weight infant than nonexposed women. Furthermore, the accumulation of PSLEs was associated with reduced infant birth weight. Conclusions This was the first nationally representative study to our knowledge to investigate the impact of PSLEs on very low and low birth weight in the United States. Interventions aimed to improve birth outcomes will need to shift the clinical practice paradigm upstream to the preconception period to reduce women’s exposure to stress over the life course and improve the long-term health of children.

Examining the link between women's exposure to stressful life events prior to conception and infant and toddler health: the role of birth weight

“…Testing models with multiples removed did not influence our findings. Given the previously identified relationship between PSLEs and VLBW, [7] we then restricted our sample to children born with VLBW (<1,500 grams) and normal birthweight (NBW; between 2,500–3,999 grams). Our final sample thus consisted of 6,900 children and their mothers who participated in the second ECLS-B data wave and who had complete covariate information.…”

“…In a previous study, Witt et al found that a woman’s exposure to stressful life events prior to conception (PSLEs) increased her risk for having a very low birthweight (VLBW) infant. [7] In turn, a large body of literature demonstrates that low birthweight contributes to infant and childhood morbidity. [8–11] The lifecourse perspective suggests a pathway may exist among PSLEs, birthweight, and subsequent child health, whereby PLSEs are part of a “chains-of-risk” that set children on a certain health pathway.…”

Maternal adversities during pregnancy and cord blood oxytocin receptor (OXTR) DNA methylation

“…Previous studies imply that maternal exposure to stressful life events even prior to conception increase the risk for infant mortality and low birth weight (Class et al, 2013;Witt et al, 2014). The finding that life changing events prior to the second trimester, but not stress experience during pregnancy per se predicted cord blood OXTR DNA methylation are in line with evidence that stressful life events during pregnancy, such as war-related stressors or exposure to natural disaster, might be a stronger predictor of DNA methylation status in the offspring as compared to more chronic stressors or subjectively perceived stress (Mulligan et al, 2012;Cao-Lei et al, 2014).…”

Second-trimester maternal distress increases the risk of small for gestational age

“…Hedegaard et al (1996) reported no significant association between maternal distress, measured using the GHQ at the 16th and 30th weeks' gestation, and birthweight or SGA. Very recently, Witt et al (2014) used population-based survey data from the USA and reported an association between maternal pre-pregnancy stressful life events and the risk of low and very low birthweight. However, contrary to our findings, there was no association between maternal stressful life events during pregnancy and the risk of LBW.…”