TY - CHAP M1 - Book, Section TI - Microcephaly A1 - Bianchi, Diana W. A1 - Crombleholme, Timothy M. A1 - D'Alton, Mary E. A1 - Malone, Fergal D. PY - 2015 T2 - Fetology: Diagnosis and Management of the Fetal Patient, 2e AB - Key PointsMicrocephaly is characterized by a smaller than normal head circumference. A head circumference measurement of 3 SD below the mean gives a clinically meaningful definition because it has been associated with mental retardation.Microcephaly has been associated with a number of genetic, infectious, and environmental exposures.Detailed ultrasound examination to exclude other anomalies is necessary.A careful history is needed when this diagnosis is suspected. Likewise, the head circumferences of the parents should be measured.Little information is known about the antenatal natural history of microcephaly, especially during the first and second trimesters.The diagnosis of microcephaly should not alter obstetric management.Newborns with microcephaly require an extensive work-up to determine the etiology of the condition.The long-term prognosis and recurrence risk for microcephaly is related to its underlying cause. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/04/19 UR - obgyn.mhmedical.com/content.aspx?aid=1106396782 ER -