When should AFP screening for neural tube defects be conducted during pregnancy?

When should AFP screening for neural tube defects be conducted during pregnancy?

• A. 10-12 weeks
• B. 12-14 weeks
• C. 16-18 weeks
• D. 20-22 weeks

Answer: (C)

The optimal time for screening with alpha-fetoprotein (AFP) for neural tube defects is during the gestational period of 16 to 18 weeks. At this stage, the production of AFP by the fetal liver has reached a level that provides reliable screening results. AFP screening is used to assess the risk of certain fetal anomalies, specifically neural tube defects, which can be detected through elevated levels of AFP in the maternal blood. This timing allows for accurate assessment and follow-up options, including further diagnostic testing if needed. Conducting the screening before 16 weeks may yield insufficient concentrations of AFP, leading to potential false negatives. Conversely, performing the test after 18 weeks could miss the optimal window for intervention or follow-up diagnostics, which is why the 16-18 week period strikes the best balance for effective screening.

The optimal time for screening with alpha-fetoprotein (AFP) for neural tube defects is during the gestational period of 16 to 18 weeks. At this stage, the production of AFP by the fetal liver has reached a level that provides reliable screening results. AFP screening is used to assess the risk of certain fetal anomalies, specifically neural tube defects, which can be detected through elevated levels of AFP in the maternal blood. This timing allows for accurate assessment and follow-up options, including further diagnostic testing if needed.

Conducting the screening before 16 weeks may yield insufficient concentrations of AFP, leading to potential false negatives. Conversely, performing the test after 18 weeks could miss the optimal window for intervention or follow-up diagnostics, which is why the 16-18 week period strikes the best balance for effective screening.