18-20 weeks Level II scan is done for
**Core Concept**
The 18-20 weeks Level II scan is a critical ultrasound examination performed during pregnancy to assess fetal anatomy and detect potential congenital anomalies. This scan focuses on visualizing the fetal heart, abdominal organs, and limbs in detail, allowing for early diagnosis of any congenital defects.
**Why the Correct Answer is Right**
The Level II scan is essential for identifying potential fetal anomalies, such as cardiac malformations, gastrointestinal abnormalities, and limb defects. During this examination, the ultrasound technician or radiologist uses a high-frequency probe to obtain detailed images of the fetal anatomy. This allows for the detection of subtle abnormalities that may not be visible on the earlier Level I (dating) scan.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the 18-20 weeks Level II scan is not primarily focused on fetal growth and development assessment, which is typically evaluated during the Level I scan.
**Option B:** This option is incorrect because the 18-20 weeks Level II scan is not typically used for assessing fetal well-being, which is usually evaluated through non-stress tests and biophysical profiles.
**Option C:** This option is incorrect because the 18-20 weeks Level II scan is not primarily focused on detecting multiple gestations, which can be identified during the Level I scan.
**Clinical Pearl / High-Yield Fact**
A key aspect of the 18-20 weeks Level II scan is the evaluation of the fetal heart, particularly the four-chamber view, to detect potential cardiac anomalies. The American Institute of Ultrasound in Medicine (AIUM) recommends that all Level II scans include a detailed examination of the fetal heart.
**Correct Answer:** C. Detecting congenital anomalies.