title: Transvaginal sonographic imaging of the low fetal head in the second trimester.
authors.affiliation: Department of Obstetrics and Gynecology, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: B R
authors.initials: BR
authors.lastname: Benacerraf
authors.forename: J A
authors.initials: JA
authors.lastname: Estroff
mesh_terms: D000328:Adult; D005260:Female; D005333:Fetus / Q000033:anatomy & histology; D006801:Humans; D007746:Labor Presentation; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D014159:Transducers; D014463:Ultrasonography / Q000379:methods*