title: The distal femoral epiphyseal ossification center in the assessment of third-trimester menstrual age: sonographic identification and measurement.
abstract: The distal femoral epiphyseal secondary ossification center (DFE), which can be reliably identified and measured sonographically, may assist the sonologist in predicting third-trimester menstrual age. Between 28 and 35 menstrual weeks, the percentage of fetuses with a DFE progressively increases. Although the mean age at DFE appearance is approximately 32-33 menstrual weeks, the DFE may be seen as early as 29 menstrual weeks. Nevertheless, the age of a fetus without an identifiable DFE is most likely less than or equal to 34 menstrual weeks. Measurements of the DFE show that its size increases linearly: the menstrual age of a fetus whose DFE measures greater than or equal to 7mm is most likely greater than or equal to 37 weeks.
mesh_terms: D005314:Embryonic and Fetal Development; D004838:Epiphyses / Q000196:embryology; D005260:Female; D005269:Femur / Q000196:embryology*; D005865:Gestational Age; D006132:Growth Plate / Q000196:embryology; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D011446:Prospective Studies; D014463:Ultrasonography