title: Detection of the small-for-dates twin fetus by ultrasound.
abstract: As methods for identifying the small-for-dates fetus in twin pregnancies, serial ultrasonic cephalometry and a new two-stage ultrasound examination schedule have been evaluated and compared. Serial cephalometry is associated with technical and interpretative problems, and only 24 (56 per cent) of 43 small-for-dates fetuses in 66 retrospectively studied twin pregnancies showed detectably abnormal biparietal diameter growth. The two-stage schedule comprises an accurate assessment of gestational age in early pregnancy, and determination of the product of the crown-rump length and trunk area at 34 to 36 weeks; this identified all 15 small-for-dates fetuses in 21 prospectively studied twin pregnancies, and the method offers several other advantages over serial cephalometry.
mesh_terms: D000886:Anthropometry; D002508:Cephalometry; D004200:Diseases in Twins; D005260:Female; D005317:Fetal Growth Retardation / Q000175:diagnosis*; D006257:Head / Q000196:embryology; D006801:Humans; D011247:Pregnancy; D011272:Pregnancy, Multiple; D011296:Prenatal Diagnosis / Q000379:methods*; D011446:Prospective Studies; D012189:Retrospective Studies; D014427:Twins; D014463:Ultrasonography