In maternal serum, alpha-fetoprotein is not elevated in which condition?

In maternal serum, alpha-fetoprotein is not elevated in which condition?

• A. Neural tube defect
• B. Spina bifida
• C. Fetal distress
• D. Down syndrome

Answer: (D)

Maternal serum alpha-fetoprotein (AFP) reflects fetal AFP leaking into the mother's blood. When the fetus has an open neural tube defect, AFP escapes into the amniotic fluid and crosses into maternal blood, leading to elevated AFP levels. Down syndrome is typically associated with lower-than-normal AFP in maternal serum, so AFP is not elevated in this condition. Thus, Down syndrome is the scenario where maternal serum AFP is not elevated. Keep in mind AFP screening is a helpful marker but not diagnostic, and results can be affected by dating accuracy, multiple gestations, and other factors.

Maternal serum alpha-fetoprotein (AFP) reflects fetal AFP leaking into the mother's blood. When the fetus has an open neural tube defect, AFP escapes into the amniotic fluid and crosses into maternal blood, leading to elevated AFP levels. Down syndrome is typically associated with lower-than-normal AFP in maternal serum, so AFP is not elevated in this condition. Thus, Down syndrome is the scenario where maternal serum AFP is not elevated. Keep in mind AFP screening is a helpful marker but not diagnostic, and results can be affected by dating accuracy, multiple gestations, and other factors.