TY - CHAP M1 - Book, Section TI - FETAL BIOMETRY A1 - Toy, Eugene C. A1 - Jeanty, Philippe A2 - Fleischer, Arthur C. A2 - Toy, Eugene C. A2 - Lee, Wesley A2 - Manning, Frank A. A2 - Romero, Roberto J. Y1 - 2015 N1 - T2 - Sonography in Obstetrics and Gynecology: Principles & Practice, 7e AB - DefinitionsBiometry: measurements of fetal somatic structures in an attempt to construct the gestational age.Biparietal diameter: transverse diameter of the fetal skull from the leading edge (outer edge) of the near field to the leading edge to the far field (inner edge of skull), through the transthallamic plane.Abdominal circumference: a measure along the outer perimeter of the fetal abdomen in a true transverse plane at the level of the junction of the umbilical vein and the hepatic vein.Dolichocephaly: abnormally shaped fetal head that is "flatter."Brachycephaly: abnormally shaped fetal head that is more round in shape.Cephalic index: the ratio of the biparietal diameter and the occipital frontal diameter. This index allows one to determine whether the fetal head is of normal shape, dolichocephalic, or brachycephalic. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/28 UR - obgyn.mhmedical.com/content.aspx?aid=1106704351 ER -