Preterm birth has been associated with greater psychological distress and less positive mother infant interactions than were experienced by mothers of full-term infants. Maternal and infant sociodemographic factors have also shown a strong association with psychological distress and the mother-infant relationship. However, findings on their effects over time are limited. In this longitudinal analysis, we explored the relationship of maternal and infant sociodemographic variables (maternal age, maternal education, marital status, being on social assistance, maternal race, infant birth weight, and infant gender) to maternal psychological distress (depressive, posttraumatic stress, anxiety, parenting stress symptoms, and maternal worry about child's health) through 12 months corrected age for prematurity, and on the home environment, and mother-infant interactions through 6 months corrected age for prematurity. We also explored differences related to maternal obstetrical characteristics (gestational age at birth, parity, mode of delivery, and multiple birth) and severity of infant conditions (Apgar scores, need for mechanical ventilation, and infant medical complications). Although the relationship of maternal and infant characteristics with these outcomes did not change over time, psychological distress differed based on marital status, maternal education, infant gender, and infant medical complications. Older mothers provided more a positive home environment. Mother-infant interactions differed by maternal age, being on public assistance, maternal race, infant gender, and infant medical complications. More longitudinal research is needed to better understand these effects over time in order to identify and support at-risk mothers.