Published online by Cambridge University Press: 10 October 2008
Diagnostic ultrasonography has achieved an almost universal role in the practice of obstetrics, due to technological improvements in equipment and the experience acquired by well-trained ultrasonographers. Within the general population, over 3% of children reportedly have major congenital malformations that are life-threatening, require major surgery or have serious cosmetic effects. Many of these malformations can be detected antenatally by obstetric ultrasound. The introduction of high frequency transvaginal ultrasonography is a major development in the area of obstetric ultrasonography. Using this method, fetal anomalies have been successfully identified as early as the first trimester of pregnancy, leading some investigators to advocate routine ultrasound examination during pregnancy in order to screen for fetal anomalies at a gestational age that permits consistently accurate diagnosis and maximizes parental choice.