The Pediatric Health Outcomes Initiative is a prospective registry that seeks to recruit 5,000 newborns (< 30 days old), and will follow them for 18 years. The goal is to determine if breastfeeding, birth delivery route, vaccination status, medications, or other factors play any role in the development of either acute or chronic diseases in children in the United States. Over the last 40 years, there has been an increase in the number of children diagnosed with both acute and chronic conditions, including asthma, eczema, allergies, attention deficit disorder (ADD), and autism. Some physicians and researchers have questioned whether any of several factors play a role in the current state of our children’s health. The PHOI registry seeks to collect prospective data to help answer this question.