Morphogenetic correlations of increased nuchal translucency in fetuses with normal first-trimester scan.

Introduction. Increased nuchal translucency (NT) at a gestational age of 11-14 weeks frequently represents the fenotipical expression of some chromosomal anomalies. Moreover, many of these syndromes associate morphological anomalies, especially in the context of an increased NT. First-trimester ultrasound scan remains the basis of prenatal care, and one of the objectives is represented by the major fetal anomalies detection. The purpose of this study is to evaluate the significance of an increased NT in fetuses with normal first-trimester morphology. Materials and method. We did a retrospective study in the Prenatal Diagnosis Center of the Emergency County Hospital of Craiova and at MEDGIN Craiova. In this study we included cases which presented for a first-trimester ultrasound genetic screening, where a detailed morphological examination protocol was followed. The patients who presented fetuses with a NT of over 3 mm underwent an invasive maneuver - chorionic villus sampling (CVS) or amniocentesis. The genetic counseling was performed prior to the maneuver. Results. Over the course of two years, 527 patients were examined, and 5% of them presented a NT of more than 3 mm. In more than 50% of these cases, an increased NT represented an isolated ultrasound marker, without any other associations, and the genetic test results were normal. In cases where increased NT and structural anomalies were present, major genetic and morphological modifications were diagnosed, with an absolute indication for the therapeutic termination of the pregnancy. Conclusions. Increased NT without any other morphological anomalies in the first-trimester ultrasound scan is associated in the majority of the cases with normal fetus karyotype and normal fetus prognosis on short and medium term (birth). However, a detailed morphological evaluation at the end of the first trimester is required in these situations, performed in a specialised center. [ABSTRACT FROM AUTHOR]