Early prenatal detection of fetal abnormalities

Abstract

Introduction: Prenatal screening for chromosomal abnormalities has become standard practice in many countries worldwide. Second-trimester risk evaluation is a frequent demand of prenatal ultrasound screening in many obstetric units. Objective: To investigate the performance of first trimester ultrasound and biochemical examination in the prediction of fetal structural anomalies and aneuploidy. Methods: This was a prospective study of 902 pregnant women with increased fetal malformation risk in the I and II trimesters of pregnancy. Selection criteria of pregnant women at risk were: advanced maternal age, pathological obstetric and family history. Results: The analysis of ultrasound fetal abnormalities in pregnant women assessed in the first trimester (83 cases), concluded that most frequently was noted increased nuchal translucency and cystic hygroma - in 53 (63.8%) cases, followed by hypoplasia of nasal bones, dismorfic profile, modified facial angles - 23 cases (27.7%, p <0.01). Rarely were detected ductus venous pathology - in 2 cases (2.4%), omphalocele (1.2%), exencephaly (1.2%) and spinal pathology, represented by the absence of intracerebral clarity - in one case. Nuchal fold and nasal bone hypoplasia were the single most sensitive parameters to identify fetuses with trisomy 21. In 2 of 4 cases, cystic hygroma caused was combined with fetal hydrops in one case (2.04 %) and unique umbilical artery - in 3 cases (6,1%). Some of the anomalies detected in the first trimester were associated with structural abnormalities detected later in pregnancy. Conclusion: Screening in the first trimester of pregnancy offer the advantage of early detection of structural malformations and ultrasound markers. The most effective screening test for anomalies is the integrated test based on the integration of the first trimester and the second trimester ultrasound markers.