This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Prenatal Diagnosis, Subject name: Gynaecology & Obstetrics
The Parameter measured in the USG, measures 3.7 mm. It is: 
Select and explain. 
A. Normal finding, B. Higher than normal, C. Lesser than normal, D. The scan should be repeated at 18 weeks
B: Higher than normal
Answer: B: Higher than normal 
Explanation: Nuchal translucency (NT) is the sonographic appearance of a collection of fluid under the skin behind the fetal neck in the first-trimester of pregnancy. In fetuses with chromosomal abnormalities, cardiac defects and many genetic syndromes -NT thickness is increased. Up to 3 mm is considered normal. More than 3 mm NT is one of the markers of Down syndrome on USG.