AbstractSince preterm infants and infants born to teenage mothers are noted to be at risk for developmental delays, a group of infants who were both preterm and born to teenage mothers was provided a sensorimotor exercise intervention program for the first year of infancy. The development of these infants was compared to the development of preterm infants without intervention and term infants of teenage mothers as well as term and preterm infants of adult mothers to determine the degree to which developmental delays were prevented. The intervention infants showed more optimal growth, cognitive development, temperament and play behaviors during interactions with their mothers across the first year of development.