Epidemiology

Prematurity is common, with an occurrence of 10.4% of live births in the US.[3]​ The incidence of prematurity is increasing despite an improved understanding of the risk factors and mechanisms surrounding preterm labor. Prematurity occurs primarily as a result of maternal or fetal causes, and also as a result of the increased utilization of assisted conception technology.[2]

The risk of preterm birth is higher in black women than white women.[4] Almost 85% of preterm infants are born between 32 and 37 weeks’ gestation.[5] 

In 2020, an estimated 13.4 million births worldwide were preterm, with southern Asia and sub-Saharan Africa accounting for 65% of these births.[6]

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