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Yu CK, Papageorghiou AT, Parra M, Palma Dias R, Nicolaides KH; Fetal Medicine Foundation Second Trimester Screening Group.Yu CK, et al. Among authors: papageorghiou at.Ultrasound Obstet Gynecol. 2003 Sep;22(3):233-9. doi: 10.1002/uog.218.Ultrasound Obstet Gynecol. 2003.PMID: 12942493Free article.Clinical Trial.