When is MSAFP ideally performed during pregnancy?

The Maternal Serum Alpha-Fetoprotein (MSAFP) test is ideally performed between 16 to 18 weeks of gestation. This timing is optimal because it allows for the most accurate assessment of alpha-fetoprotein levels, which can help screen for certain fetal abnormalities, such as neural tube defects and Down syndrome. During this period, the levels of MSAFP in the mother's blood are at a point where they can provide significant information about the health of the fetus.

Testing too early or too late may result in either false positives or negatives, as the concentration of alpha-fetoprotein in maternal serum can vary greatly during pregnancy. Therefore, scheduling the MSAFP test during the 16 to 18 weeks window enhances the reliability of the results.