ABSTRACT
During gestation, multiple maternal, fetal, and placental factors interact to determine adequate fetal growth. Nonetheless, in a considerable proportion of pregnancies, fetal growth will be above or below the expected for gestational age (GA). Actually, there are no universally accepted criteria for the diagnosis of abnormal fetal growth. Commonly used definitions are based on the discrepancy between actual and expected biometric ultrasound measurements for a given GA using arbitrary threshold percentiles, labeling fetuses as “small for GA” or “large for GA”, resembling the diagnosis of malnutrition in children. Regarding management, once fetal macrosomia is suspected, an elective cesarean section can be done to avoid complications related to vaginal delivery. However, the number of interventions needed to prevent one complication makes this approach clinically and economically unsound. Fetal growth is a complex and dynamic process that is heavily modulated by placental function, with the placenta serving the critical respiratory, hepatic, and renal functions of the fetus.
