Ultrasound and Diagnosis of Fetal Anomalies

Abstract

ABSTRACT Background Congenital abnormalities account 20 to 25% of perinatal deaths. Now, many genetic and other disorders can be diagnosed early in pregnancy. Screening examinations during pregnancy are an essential part of prenatal care. Among the various screening tests that are now offered to pregnant women, ultrasound (US) has the broadest diagnostic spectrum. There is no modality that can detect as many abnormalities during pregnancy as US. A priority goal in screening is the early detection of major fetal anomalies, which are defined as malformations that affect fetal viability and/or quality of life. During the past 10 years, some multicentric studies in Europe and USA show the successfulness of US diagnostics in detecting congenital abnormalities, even in women with low-risk pregnancy. The term sonoembryology designates the description of the embryonic anatomy, the normal anatomic relations and the development of abnormalities as visualized by ultrasound. To confirm the presence of normal anatomy or to make the diagnosis of an anomaly, we need knowledge of the normal embryonic development, including the appearance of the normal embryo. Definition of fetal anomalies Any deviation from the normal range during morphogenesis, constitutes an anomaly. Major anomalies are malformations that affect viability and/or the quality of life and require intervention, and minor anomalies are malformations that are definitely present, but are minimal and usually have no functional significance (e.g. ear tags). Incidence data on major congenital anomalies vary considerably, depending on the type of detecting system used. The passive detection system reports 2 to 3% of newborns, meanwhile the active detection system, in which newborns are systematically examined by trained obstetricians, reports the incidence of congenital defects in 7.3% of all newborns. Etiology About 20% of anomalies in live-born infants are based on a defective gene, 10% are due to chromosomal abnormalities and 10% are mainly due to exogenous injury to the conceptus. Some 60% of all congenital anomalies are indeterminate or multifactorial causes (hereditary factors and environmental influences). US can detect about 74% of major birth defects and possibly a higher number, when conducted by a well-trained specialist. We have demonstrated in this paper some fetal anomalies found by US during our practice in Tirana and Prizren. There are some anomalies of the CNS, neural tube defects, anomalies of the head, neck and spine, thoracic and cardiac anomalies, gastrointestinal and urinary tract anomalies as well as some extremities anomalies. Conclusion US diagnostic is a very useful method for evaluating the fetal health, fetal anomalies, anomalies of placenta and amniotic fluid as well as umbilical cord.