title: The femur length/head circumference relation in obstetric sonography.
abstract: The relationship of sonographic femur length to biparietal diameter (BPD) in utero may be useful in detecting short-limb dwarfism, hydrocephaly, microcephaly, and measurement errors. Because BPD can be adversely affected by head shape changes (e.g., dolichocephaly), falsely high or low values of femur length/BPD could result. Because head circumference is less affected by head shape changes than is BPD, it should be a better standard of head size against which to judge limb length. The authors report normal values for the relationship between femur length and head circumference, based on a cross-sectional analysis of 361 normal fetuses (15-42 weeks) using real-time ultrasound.
mesh_terms: D002508:Cephalometry; D004392:Dwarfism / Q000175:diagnosis; D005314:Embryonic and Fetal Development; D005260:Female; D005269:Femur / Q000033:anatomy & histology*; D005865:Gestational Age; D006257:Head / Q000033:anatomy & histology*; D006801:Humans; D008831:Microcephaly / Q000175:diagnosis; D011247:Pregnancy; D011296:Prenatal Diagnosis; D012016:Reference Values; D014465:Ultrasonics; D014463:Ultrasonography