In fetal alcohol syndrome, alcohol crosses the placenta and fetal blood alcohol levels are equal to maternal levels.

In fetal alcohol syndrome, alcohol crosses the placenta and fetal blood alcohol levels are equal to maternal levels.

• A. True
• B. False
• C. Unknown
• D. Sometimes

Answer: (A)

Ethanol crosses the placenta by simple diffusion, so it moves freely between mother and fetus and the fetal and maternal blood concentrations come into close equilibrium. Because the fetus has limited ability to metabolize alcohol quickly, the clearance is slower in the fetus, meaning exposure persists even as maternal levels fall. In practice, fetal blood alcohol levels mirror maternal levels during exposure, which is why this statement is true. This mechanism helps explain why alcohol exposure in pregnancy can reliably affect fetal development, contributing to fetal alcohol syndrome.

Ethanol crosses the placenta by simple diffusion, so it moves freely between mother and fetus and the fetal and maternal blood concentrations come into close equilibrium. Because the fetus has limited ability to metabolize alcohol quickly, the clearance is slower in the fetus, meaning exposure persists even as maternal levels fall. In practice, fetal blood alcohol levels mirror maternal levels during exposure, which is why this statement is true. This mechanism helps explain why alcohol exposure in pregnancy can reliably affect fetal development, contributing to fetal alcohol syndrome.