A 27-year-old primigravida undergoes first-trimester screening. Nuchal translucency measures 4.2 mm. Chorionic villus sampling returns a normal karyotype (46,XX). What is the most appropriate next step in the further evaluation of this fetus?
- A Fetal echocardiography and detailed anomaly scan ✓
- B Reassure and continue routine antenatal care
- C Serial amniocentesis for AFP estimation
- D Immediate termination of pregnancy
Correct answer: A. Fetal echocardiography and detailed anomaly scan
Explanation
An NT of 3.5 mm or greater, even with a normal karyotype, carries a substantially increased risk of structural anomalies, particularly congenital heart disease, diaphragmatic hernia, skeletal dysplasias and genetic syndromes such as Noonan syndrome. Fetal echocardiography with detailed mid-trimester anomaly assessment is therefore indicated. Reassurance is inappropriate because chromosomal normality does not exclude structural disease, and termination is offered only if a lethal anomaly is confirmed.
Reference: Fetal Medicine by RCOG / Obstetrics by Ten Teachers, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.