title: Comment on "what is predictive of preterm delivery in the first trimester: isthmus or cervical length?".
authors: Fetal Medicine Unit, Instiuto Nacional Materno Perinatal, Lima, Peru; Instituto Latinoamericano de Salud Reproductiva ILSAR, Lima, Peru.
authors: Walter
authors: W
authors: Ventura
authors: Moisés
authors: M
authors: Huaman-Guerrero
mesh_terms: D054791:Cervical Length Measurement / Q000379:methods*; D002584:Cervix Uteri / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D047928:Premature Birth / Q000000981:diagnostic imaging*; D014599:Uterus / Q000000981:diagnostic imaging*