The specific aim is to explore potential relationships between synOT, birth/postbirth factors and postpartum depressive symptoms, while controlling for covariates (Fig 1).

H1: in 8000 cases, less optimal birth factors will predict elevated postpartum depressive symptoms at two months, and the negative influence will be lessened by more optimal postbirth factors.

H2: in a matched subset of postpartum women with or without elevated depressive symptoms, increased synOT dosage will predict elevated postpartum depressive symptoms at two months, and the negative influence will be lessened by more optimal birth and postbirth factors.

Our long term goal is to promote optimal birth experiences (birth-care that supports normal physiology and a woman's positive perception) that enhance postpartum maternal mood and healthy mother-infant interaction, thus supporting infant development.37

Collaborators include Aleeca Bell PhD, expert in midwifery, Jean Golding PhD, expert in perinatal epidemiology; John Davis PhD, neurobehavioral expert in psychiatric disorders; Sue Carter PhD, neurobehavioral expert in oxytocin; and Leah Rubin PhD, methods and statistical analysis expert.