AC
Also written as: AC — Abdominal Circumference
Abdominal Circumference - a key fetal biometric measurement used to assess growth and estimate fetal weight.
Full Definition
Abdominal Circumference (AC) is a standard biometric measurement in obstetric ultrasound, taken at the level of the stomach and umbilical vein insertion into the liver. It is considered the most sensitive single parameter for detecting fetal growth abnormalities, as it reflects liver size and glycogen storage. AC measurements are plotted against gestational age percentiles and combined with other biometrics to calculate estimated fetal weight. Abnormal AC growth patterns can indicate intrauterine growth restriction or macrosomia.
Usage
Usage note: Always specify measurement in millimeters and reference to gestational age percentiles.
In Context
- "The AC measured 285mm, placing the fetus below the 10th percentile for gestational age." — Growth assessment ultrasound
- "Serial AC measurements showed appropriate interval growth over four weeks." — Follow-up biometry report