A pregnant woman undergoes maternal serum screening. Elevated alpha-fetoprotein levels are detected. This finding is most indicative of which fetal condition?
- A Down syndrome
- B Neural tube defect ✓
- C Omphalocele
- D Turner syndrome
Correct answer: B. Neural tube defect
Explanation
Elevated maternal serum alpha-fetoprotein is a classic marker for open neural tube defects, such as anencephaly or spina bifida, because fetal plasma proteins leak into the amniotic fluid and maternal circulation. Down syndrome is associated with low alpha-fetoprotein, high hCG, and low estriol. Omphalocele can raise alpha-fetoprotein, but neural tube defects are the primary association.
Reference: Williams Obstetrics, 26th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.