title: Extended culture and the risk of preterm delivery in singletons: confounding by indication?
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Forman
authors.forename: Marie D
authors.initials: MD
authors.lastname: Werner
authors.forename: Richard T
authors.initials: RT
authors.lastname: Scott
mesh_terms: D004624:Embryo Transfer / Q000379:methods*; D005260:Female; D006801:Humans; D011247:Pregnancy; D047928:Premature Birth / Q000453:epidemiology*; D012042:Registries