Preterm Birth in the United States: The Impact of Stressful Life Events Prior to Conception and Maternal Age

Abstract

Objectives We determined whether and to what extent a woman’s exposure to stressful life events prior to conception (PSLEs) was associated with preterm birth and whether maternal age modified this relationship. Methods We examined 9350 mothers and infants participating in the first wave of the Early Childhood Longitudinal Study, Birth Cohort, a nationally representative sample of US women and children born in 2001, to investigate the impact of PSLEs on preterm birth in the United States. We estimated the effect of exposure on preterm birth with weighted logistic regression, adjusting for maternal sociodemographic and health factors and stress during pregnancy. Results Of the women examined, 10.9% had a preterm birth. In adjusted analyses, women aged 15 to 19 years who experienced any PSLE had over a 4-fold increased risk for having a preterm birth. This association differed on the basis of the timing of the PSLE. Conclusions Findings suggest that adolescence may be a sensitive period for the risk of preterm birth among adolescents exposed to PSLEs. Clinical, programmatic, and policy interventions should address upstream PSLEs, especially for adolescents, to reduce the prevalence of preterm birth and improve maternal and child health.

Maternal and neonatal factors related to prematurity

“…Adolescent women (under the age of 20) and those with an advanced age (older than 34 years old) presented an association with premature delivery, corroborating to the existing literature (9)(10)(11)(12)(13) . A cross-sectional study conducted in Feira de Santana-BA showed that the risk of premature birth increased with the decrease in the mother's age, which can reach a relative risk of 10 times higher in women up to the age of 16 years old (14) .…”

“…It is unclear whether the mother's age is an independent risk factor with a direct effect on prematurity, or if it acts indirectly, associated with confounding agents such as chronic diseases or sociodemographic factors. What is known is that the mother's advanced age is related to an increase in the prevalence of preexisting chronic diseases and of medical problems during pregnancy and delivery (11) . In Porto Alegre, the number of women who have become pregnant at an advanced age had a small increase in the last five years of 1.8%, from 16.1% in 2008 to 17.9% in 2012 (7) .…”

Do Physical Activity Patterns Across the Lifecourse Impact Birth Outcomes?

“…For instance, stress has been shown to be a risk factor for preterm birth, especially during sensitive periods, such as adolescence and early adulthood [29]. Whereas the biological mechanisms by which stress may impact pregnancy has not yet been made clear within the literature, physical activity is known to be a key health behavior to cope with stress and improve mental well-being [30].…”

Comparison of black–white disparities in preterm birth between Canada and the United States

“…[1][2][3] This racial disparity is of great concern because preterm birth is a leading cause of perinatal mortality and is predictive of developmental problems and adverse health outcomes later in life. 4 The underlying causes of the racial disparity in preterm birth in the US are not well understood, although research has suggested contributing roles for a wide range of factors, including socioeconomic disadvantage, 5 poor neighbourhood conditions (e.g., poverty, crime), 5,6 lack of access to health care, 7 psychosocial stress, 8 racial discrimination 9 and adverse health behaviours. 10 Rates of preterm birth have consistently been lower in Canada than in the US.…”