The antenatal diagnosis of fetal anomalies and chromosomal abnormalities [Article in Bosnian]

Abstract

Various methods are in use in prenatal diagnosis of fetal abnormalities. These methods could be divided into two groups: invasive and non-invasive procedures. Various techniques of ultrasound examination play the leading role, and could be combined with biochemical markers or invasive procedures. A very important step in the early diagnosis of fetal abnormalities is transvaginal ultrasound examination at the end of first trimester of pregnancy at 14 gestational weeks. The aim of this examination is to find morphological anomalies and ultrasound markers which are in a high percentage connected with chromosomal abnormalities. The basic morphological details that can be noticed in this period are: the symmetry of the hemispheres, the cerebellum, chorioid plexus, lateral ventricles, anterior abdominal wall, back, upper and lower extremities, spine, heart, diaphragm, stomach, kidneys and bladder. The ultrasound markers at the end of the first trimester and during the second trimester of pregnancy are: nuchal translucency thickness, cystic hygroma, the absence of nasal bones, dilatation of pyelon more than three millimetres, omphalocela, choriod plexus cysts, hyperechogenic bowel, the shortening of long bones and abnormal flow in the ductus venosus. The biochemical markers for chromosomal abnormalities, such as beta human chorionic gonadotropin, unconjugated estriol and alpha-fetoprotein are measured in the maternal serum. This test is known as a »triple test«. The invasive procedures for detecting fetal kariotype from fetal cells, placental tissue and chorionic villi are chorion villus sampling, placentocentesis and amniocentesis. The other methods like biopsy of various fetal tissues and fetal steam cells are still not routine methods.