This article reviews the epidemiology and risk factors of posthemorrhagic hydrocephalus and neural tube defects (NTDs). Posthemorrhagic hydrocephalus is discussed in terms of risk factors for intraventricular hemorrhage. Four categories of risk factors are presented: maturational factors, antepartum factors, peripartum factors, and factors conferred by postnatal conditions. The complex epidemiology of neural tube defects is discussed in terms of person, place, and time. Interventional strategies, including antenatal screening and nutritional supplementation for NTD prevention, are reviewed.