Developmental Impacts of Microplastics Exposure in Early Life

The goal of this observational study is to characterize and evaluate micro- and nano-plastic (MNP) exposures among mothers and infants in mother-infant dyads 1 or 3 months postpartum living in Baltimore, Maryland. The main questions it aims to answer are: * What MNPs are present in breastmilk and maternal blood samples and in their infants stool sample? * Are there associations between amount of maternal MNPs in breast milk and mass of MNP particles in infant stool? * Which environmental and lifestyle factors are most predictive of maternal MNP burden? * Is infant exposure to MNPs associated with birth weight and postnatal growth trajectories? Participants will: * Complete several questionnaires assessing medical histories, lifestyle factors, environmental exposures, eating behaviors, etc. * Provide biological specimens including: maternal blood, stool, and breastmilk; infant stool * Clinical visit to have anthropometric measures documented including maternal height and weight, infant weight, length, and skin-fold thickness