Sonographic Measurement of the Fetal Mandible: Standards for Normal Pregnancy

Abstract

Measurements of the fetal mandible were made on 204 women with uncomplicated pregnancies and reliable gestational dates. The measurements were made in the sonographic plane, which included the fetal mandible and the hypopharynx. The anteroposterior and transverse jaw measurements increased with gestational age (p p <0.0001). Measurements were technically more difficult to obtain during the late third trimester. These standards for fetal jaw measurement may be useful in the sonographic identification of micrognathia.