PU Fetal Biometry and Growth Assessment 2

Question 1

Which bone is measured to assess femur length (FL) in fetal biometry?

Accepted Answer

The longest bone in the fetal thigh

Answer

Femur length is measured along the ossified diaphysis of the femur, the longest bone in the fetal thigh.

Question 2

What does a head circumference to abdominal circumference (HC/AC) ratio greater than 1.0 after 36 weeks suggest?

Accepted Answer

Asymmetric IUGR

Answer

An HC/AC ratio greater than 1.0 after 36 weeks suggests asymmetric IUGR, where the brain is spared but the liver and abdominal organs are affected.

Question 3

Serial ultrasound exams to monitor fetal growth are typically performed how far apart?

Accepted Answer

Every 3–4 weeks

Answer

Serial growth scans are typically scheduled every 3 to 4 weeks, as shorter intervals do not allow enough time to detect meaningful growth changes.

Question 4

What is macrosomia defined as in ultrasound practice?

Accepted Answer

Estimated fetal weight above the 90th percentile

Answer

Macrosomia is defined as an estimated fetal weight above the 90th percentile for gestational age, or commonly above 4,000–4,500 grams at term.

Question 5

Which measurement is most affected by fetal head shape variations such as dolichocephaly?

Accepted Answer

Biparietal diameter (BPD)

Answer

BPD can be falsely low in dolichocephaly (elongated head) or falsely high in brachycephaly, making HC a more reliable measurement in these cases.

PU - Pregnancy Ultrasound Certification Practice Test