Importance Preterm birth has been difficult to study and prevent because of its complex
syndromic nature. Objective To identify phenotypes of preterm delivery syndrome in the
Newborn Cross-Sectional Study of the INTERGROWTH-21st Project. Design, Setting, and
Participants A population-based, multiethnic, cross-sectional study conducted at 8
geographically demarcated sites in Brazil, China, India, Italy, Kenya, Oman, the United
Kingdom, and the United States. A total of 60 058 births over a 12-month fixed period …