Impaired fetal growth: ultrasonic evaluation and clinical management.

Although biparietal diameter has become the standard fetal dimension for dating purposes, it is accurate in the diagnosis of intrauterine growth retardation in only 50% of cases. Serial assessment of the abdominal circumference, on the other hand, may allow more accurate identification of impaired growth. The combined use of biparietal diameter and abdominal circumference in the estimation of fetal weight in utero directly addresses the basis of the diagnosis of impaired fetal growth. Ultrasonic observation of amniotic fluid volume, fetal muscle tone, and the texture of the placenta may also be valuable in the diagnosis of intrauterine growth retardation. Once a diagnosis of impaired fetal growth is made, the clinical management includes, possibly, treatment of maternal factors that may be contributing to the growth retardation and monitoring of fetal and maternal well being with delivery if serious deterioration of either mother or fetus is noted. Maximal safe retention in utero is the management goal, as long as some growth is noted and acute distress is not seen.