Very preterm born neonates (24-32 weeks gestation) are exposed to stressful and painful procedures during neonatal intensive care. Analgesic and sedation therapies are essential, and opiates and benzodiazepines are commonly used. These medications may negatively impact brain development. The hippocampus may be especially vulnerable to the effects of pain and analgesic and/or sedative therapies and contribute to adverse outcomes. The association of invasive procedures and analgesic-sedative exposure on hippocampal growth was assessed, as was hippocampal growth on neurodevelopmental outcome.