Down Syndrome Biomarkers: Statement Analysis

This question concerns common biomarkers used in pregnancy to screen for Down syndrome (Trisomy 21). We need to evaluate the accuracy of statements regarding the typical levels of $\beta$ HCG, $\alpha$ FP, and Inhibin in pregnancies affected by Down syndrome.

Biomarker Levels in Down Syndrome Pregnancies

• Statement 1: $\beta$ HCG is raised. This statement is correct. Levels of the hormone human chorionic gonadotropin ($\beta$ HCG) are typically found to be significantly higher than normal in the maternal serum during pregnancies with Down syndrome.
• Statement 2: $\alpha$ FP is raised. This statement is incorrect. $\alpha$-fetoprotein ($\alpha$ FP) levels are usually found to be decreased in pregnancies affected by Down syndrome, not raised.
• Statement 3: Inhibin is decreased. This statement is incorrect. Inhibin-A levels are typically found to be increased in pregnancies with Down syndrome, not decreased.

Conclusion on Correct Statements

Based on the analysis:

• Statement 1 is correct.
• Statement 2 is incorrect.
• Statement 3 is incorrect.

Therefore, only statement 1 is correct.

Final Answer Determination

The question asks which of the statements is/are correct. Only Statement 1 is correct.

This corresponds to Option B.