Observational StudyImpact of Reading on Endogenous Oxytocin System of Preterm Infants

The purpose of this study is to learn how early language exposure may be related to changes in DNA in parents and their premature infants. While a person's genetic code is determined at the time of conception, the way that some genes are expressed in the body can be changed even after an individual is born. These changes are called epigenetic changes. In this study, the investigators want to learn about the epigenetic changes that happen after a premature baby is born and whether a parent's interaction with their baby can influence these epigenetic changes. The investigators will look at epigenetic changes by collecting saliva samples from parents and their preterm babies, here defined as babies born at <33 weeks gestation. Specifically, the investigators will be looking at salivary levels of DNA methylation of the oxytocin receptor gene (OXTRm). The investigators will track changes in OXTRm levels over time in parents and their babies and see if these levels change in relation to how much time parents spend with their babies and how much time they spend reading to their babies. The investigators will ask mothers and, if desired, their partners to read to their babies for at least 15 minutes per week. The investigators will ask them to track time spent with the baby and reading time on a log, and will also measure word count with a commercially-available LENA device. The investigators will use logistic regression analysis to identify the independent association between OXTR DNA methylation and time spent with parent(s) and word count.