First-trimester Screening: An Overview

An improvement in prenatal screening for chromosomal defects has been achieved by combining sonography and biochemical markers. Analyzing markers taken from maternal blood such as pregnancy-associated plasma protein A and free β-human chorionic gonadotropin in combination with the ultrasound marker nuchal translucency provides detection rates of 90% for the most important chromosomal anomalies. In addition, nuchal translucency is a marker for severe heart defects. This report discusses the potential of new markers such as the nasal bone.