Ten reasons why we should not abandon a detailed first trimester anomaly scan
Karl Oliver Kagan, Sevgi Tercanli, Markus Hoopmann
Abstract
Within the last two decades, the first trimester screening at 11–13 weeks' gestation has evolved from a simple measurement of the nuchal translucency (NT) thickness and the crown-rump length (CRL) towards a detailed risk stratification for several complications that may happen within the course of the pregnancy [1] [2]. As a consequence, first trimester screening is now considered crucial for the management of each pregnancy. It involves a detailed risk assessment for chromosomal abnormalities, especially for trisomy 21, for preeclampsia and fetal growth restriction as well as a detailed anomaly scan [3] [4] [5] [6] [7] [8] [9]. In a meta-analysis from Karim et al., the detection rate for fetal defects in a high risk population exceeded 60 % [5]. These positive aspects have resulted in the concept of "turning the pyramid of pregnancy care". In short, this model relies on a detailed first trimester risk assessment and stratifies the further management of the pregnancy according to the respective risk profile [10].