Increased amniotic fluid or maternal serum alpha-fetoprotein is associated with which fetal condition?

Increased amniotic fluid or maternal serum alpha-fetoprotein is associated with which fetal condition?

• A. Down syndrome
• B. Preeclampsia
• C. Neural tube defects such as anencephaly and spina bifida
• D. Fetal alcohol syndrome

Answer: (C)

Elevated alpha-fetoprotein in the mother’s blood or in amniotic fluid signals an open defect in the fetus’s neural tube. AFP is made by the fetal liver and yolk sac and normally stays out of maternal circulation or is present in only small amounts. If the neural tube doesn’t close properly, fetal tissues are exposed to the amniotic cavity and maternal blood, allowing AFP to leak and raise screening levels. This pattern is classically seen with open neural tube defects like anencephaly and spina bifida. Other conditions listed don’t typically cause a marked rise in AFP, with Down syndrome more often showing normal or even reduced AFP, and preeclampsia or fetal alcohol syndrome not being defined by elevated AFP.

Elevated alpha-fetoprotein in the mother’s blood or in amniotic fluid signals an open defect in the fetus’s neural tube. AFP is made by the fetal liver and yolk sac and normally stays out of maternal circulation or is present in only small amounts. If the neural tube doesn’t close properly, fetal tissues are exposed to the amniotic cavity and maternal blood, allowing AFP to leak and raise screening levels. This pattern is classically seen with open neural tube defects like anencephaly and spina bifida. Other conditions listed don’t typically cause a marked rise in AFP, with Down syndrome more often showing normal or even reduced AFP, and preeclampsia or fetal alcohol syndrome not being defined by elevated AFP.