Fetal nuchal skin thickness is useful in detecting: March 2012
**Core Concept**
Fetal nuchal skin thickness refers to the thickness of the skin at the back of the fetal neck, measured via ultrasound. This measurement is an important marker for detecting certain fetal abnormalities. The **nuchal translucency** measurement is closely related and is used as a screening test.
**Why the Correct Answer is Right**
An increased nuchal skin thickness is associated with an elevated risk of **chromosomal abnormalities**, particularly **Down syndrome (Trisomy 21)**. The mechanism behind this association involves the accumulation of fluid in the nuchal area, which can be detected as increased skin thickness. This is thought to result from impaired lymphatic drainage.
**Why Each Wrong Option is Incorrect**
**Option A:** Not directly related to nuchal skin thickness.
**Option B:** Not directly related to nuchal skin thickness.
**Option C:** Not directly related to nuchal skin thickness.
**Option D:** Not provided, but assuming it's not related to the correct answer.
**Clinical Pearl / High-Yield Fact**
An important point to remember is that nuchal translucency measurements are most accurate between 11 and 14 weeks of gestation.
**Correct Answer:** D. Down syndrome