Fetal Size and Dating: Charts Recommended for Clinical Obstetric Practice

Abstract

Dating measurements are used to confirm the postmenstrual dates (if known) or to estimate the gestational age (GA) of the fetus when the menstrual history is unknown or unreliable. Normally the earliest technically satisfactory measurement will be the most accurate for dating purposes. Once the gestational age has been assigned, later measurements should be used to assess fetal size and should not normally be used to reassign gestational age.