Fetal Microcephaly has an incidence of 2 to 12 in 10,000 births in the USA and can be diagnosed prenatally via ultrasound (in second or early third trimester) or postnatally via measurement of head circumference (HC). Antepartum, this is a unique diagnosis since we are mainly used to using PERCENTAGES for biometrics and for fetal weight, but microcephaly is not diagnosed by HC percentage- but by Standard Deviation (SD). Microcephaly has been linked to developmental delay, seizures, as well as feeding, vision and hearing problems. Prognosis depends on the severity of the microcephaly and whether it is associated with other anomalies. What SD is diagnostic of microcephaly? What are the potential etiologies? What genetic syndromes are most associated with true microcephaly? Is fetal cranial MRI recommended? Listen in for details.

1. Sukenik-Halevy R, Golbary Kinory E, Laron Kenet T, Brabbing-Goldstein D, Gilboa Y, Basel-Salmon L, Perlman S. Prenatal gender-customized head circumference nomograms result in reclassification of microcephaly and macrocephaly. AJOG Glob Rep. 2023 Jan 29;3(1):100171. doi: 10.1016/j.xagr.2023.100171. PMID: 36864987; PMCID: PMC9972400.

2. SOGC CO (2019) No. 380-Investigation and Management of Prenatally Identified Microcephaly

3. Fetal Medicine Foundation: Microcephaly; https://fetalmedicine.org/education/fetal-abnormalities/brain/microcephaly