Modeling the types and timing of stress in pregnancy

In the current study we examined whether or not stress at critical intervals during pregnancy, or stress consistently experienced across the course of pregnancy was associated with gestational age in a (large) multiethnic sample. After deriving a latent trait-state model of stress, we examined whether or not particular components of stress (i.e., perceived stress, general anxiety, pregnancy-specific anxiety), or stress in general, at specific time points or over time were associated with gestational age. Pregnancy-specific anxiety over the course of pregnancy was associated with shorter gestation after controlling for a number of risk factors, including history of diabetes, smoking, maternal age, and parity. Moreover, these findings suggest that the relation between pregnancy-specific anxiety and gestational age was similar across ethnic groups. The importance of modeling the components and timing of stress with latent variable methodology is discussed.