P03The value of ultrasound screening for fetal abnormalities in the first trimester

Abstract

Objective Evaluation of routine screening in the early pregnancy by transvaginal sonography (TVS) in an unselected population. Design and methods: A routine ultrasound examination was offered to every woman in the 12th week of her pregnancy. Besides a detailed survey of fetal anatomy, a measurement of nuchal translucency and karyotyping was performed as appropriate. Results In a five‐year period (from 1. Jan. 1995 – to 31. Dec. 1999) 9556 women were examined. Fetal anomalies were diagnosed in 54 cases at the 12th week of pregnancy: 63 morphological abnormalities and 16 chromosomal aberrations. The detection rate for structural and chromosomal abnormalities in early pregnancy was 50.5% (54/107) of all anomalies, which were diagnosed antenatally. Conclusions It is possible to detect fetal abnormalities very early in pregnancy. The ultrasound screening may increase the detection rate of chromosomal disorders. The interpretation of fetal anatomy in the first trimester requires comprehensive understanding of embryological development. The detection rate of fetal malformations is increased significantly by introducing an early pregnancy scan in addition to the mid‐trimester scan. The fetopathological examination can add more information to the clinicians and to genetic counselling.