title: Reply: To PMID 21210485.
authors: Department of Obstetrics and Gynecology, Stanford University School of Medicine, Stanford, California USA (Y.J.B.), Department of Obstetrics and Gynecology, Brown University School of Medicine, Providence, Rhode Island USA (D.J.R.).
authors: Yair J
authors: YJ
authors: Blumenfeld
authors: Department of Obstetrics and Gynecology, Stanford University School of Medicine, Stanford, California USA (Y.J.B.), Department of Obstetrics and Gynecology, Brown University School of Medicine, Providence, Rhode Island USA (D.J.R.).
authors: Dwight J
authors: DJ
authors: Rouse
mesh_terms: D000650:Amnion / Q000000981:diagnostic imaging*; D002823:Chorion / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D011247:Pregnancy; D011272:Pregnancy, Multiple; D016216:Ultrasonography, Prenatal / Q000639:trends*