Ultrasonographic evaluation of normal fetal anatomy and congenital malformations

Abstract

Congenital fetal malformations continue to represent a significant and growing problem in perinatal morbidity and mortality. Unfortunately, preventive measures are almost impossible and the only realistic approach to this problem lies in early antenatal detection. The fetus had been virtually inaccessible to observation until the development of ultrasonography, fetoscopy, and amniocentesis. With the improved sophistication of the high resolution gray scale ultrasonic equipment, delineation of the ultrafine intrafetal structures has become a reality. Diagnostic ultrasound, along with recent technological advances in medical genetics, offers an additional perspective for assessing the fetal well-being in utero. These methods have facilitated the prenatal diagnosis of an increasing number of congenital disorders. With the recent widespread availability of real time scanners, continuous observation of the dynamic aspects of the unborn child is now possible. Fetal body and breathing movements can readily be quantified. tions for ultrasound examination of pregnancies in order to exclude congenital anomalies, including: 1) prior to amniocentesis to determine gestational age and placental localization and to establish fetal life and number; 2) in a woman with a history of previous children with a structural birth defect if the defect can be diagnosed by ultrasound; 3) with a finding of elevated alpha-fetoprotein in the maternal serum or amniotic fluid in order to detect any neural tube defect or gastroschisis; and 4) with a finding of amniotic fluid abnormalities such as polyhydramnios or oligohydramnios in order to detect possible renal or intestinal anomalies.