Lending a helping hand to preterm infants: Randomized controlled trial of the impact of ‘sticky mittens’ on exploratory behavior and later development

Research with 3-month-old infants from the general population has shown benefits to their exploratory behavior from play involving 'sticky mittens'. Sticky mittens are Velcro-covered mittens that are used with Velcro-covered toys to enable pre-reaching infants to grab and move toys simply by swatting at them. Our randomized controlled trial examined whether sticky mittens play, supervised by parents in the home environment, could similarly improve the exploratory behavior and later development of preterm infants. Participants (N = 62, 25-33 weeks of gestation) were recruited at 3 months of age corrected for prematurity and assigned randomly to either an intervention or active control group. For up to 5-10 min per day for three weeks, the intervention group used sticky mittens regularly while the control group instead watched their caregiver move the toys. Object-oriented exploratory behavior was evaluated immediately before and after the intervention, and caregivers completed questionnaires about their infant's development until 15 months' corrected age. Results showed that the intervention group made significantly greater gains than the control group in mouthing, F = 9.24, p = .004, η_p² = 0.13, and bimanual exploration of the toys at or near the mouth, F = 8.07, p = .006, η_p² = 0.12. However, the groups showed equivalent development over the next year as gauged by parent-report questionnaires p's > 0.05. While the sticky mittens intervention has immediate benefits for preterm infants' exploratory behavior, more research is needed before conclusions can be drawn regarding the longer-term impact on their development.