Provider type and preterm birth in New York City births, 2009-2010.This cross- sectional analysis assessed the role of provider type in preterm birth (PTB) using birth certificates (2009– 2010) from the New York City Department of Health and Mental Hygiene for singleton births to adult, low- risk women (n=73,887). 
birth certificates
Provider type and preterm birth in New York City births, 2009-2010.This cross- sectional analysis assessed the role of provider type in preterm birth (PTB) using birth certificates (2009– 2010) from the New York City Department of Health and Mental Hygiene for singleton births to adult, low- risk women (n=73,887). 
the New York City Department of Health and Mental Hygiene