Preterm birth in the US: The importance of preconception stressful life events and pregnancy-related determinants

OBJECTIVE: To evaluate the association among preconception stressful life events, pregnancy-related risk factors, and preterm birth.

METHODS: Data are from the Early Childhood Longitudinal Study-Birth Cohort, a nationally representative, population-based survey of women delivering a live baby in 2001 (n=9,350). Preterm births were defined as deliveries at less than 37 weeks of gestation. Logistic regression examined the role of sociodemographics, health, healthcare, and stressful life events (before and during pregnancy) on preterm birth.

RESULTS: 11% of US women delivered a preterm baby. Preconception stressful life events were associated with increased odds of delivering a preterm birth (OR: 3.91, 95% CI: 2.47-6.18). Women also had higher odds of delivering a preterm baby if they experienced any pregnancy complications, had a prior preterm birth or baby born small-for-gestational age, were black (non-Hispanic) or Hispanic, delivered multiples, or were of lower socioeconomic status. Stressful life events during pregnancy, prepregnancy body mass index, marital status at birth, timing of initiation of prenatal care, health insurance coverage, number of children in the household, and US region of residence were not associated with higher odds of delivering a preterm baby.

CONCLUSIONS: This national study showed that exposure to preconception stressful life events and certain pregnancy-related factors were strong predictors of preterm birth. Women's exposure to stressful life events needs to be assessed and mitigated prior to pregnancy. Preconception care is an essential part of women's healthcare and should be incorporated into efforts underway on many fronts to reduce the risk for preterm birth.