title: A composite curve of ultrasonic biparietal diameters for estimating gestational age.
mesh_terms: D002508:Cephalometry / Q000379:methods; D005260:Female; D005865:Gestational Age; D006801:Humans; D011247:Pregnancy; D012016:Reference Values; D012886:Skull / Q000196:embryology; D014463:Ultrasonography