[How to appraise the cervix uteri in obstetrical ultrasonography].
Mario Henrique Burlacchini de
MH
Carvalho
D002584:Cervix Uteri / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007752:Obstetric Labor, Premature / Q000000981:diagnostic imaging; D011247:Pregnancy; D016216:Ultrasonography, Prenatal / Q000379:methods*