Final answer:
A serum alpha-fetoprotein test is used to screen for certain fetal abnormalities, such as neural tube defects. Abnormal levels of AFP can indicate the possibility of conditions like spina bifida or anencephaly. Further diagnostic testing may be recommended if the AFP levels are significantly higher or lower than normal.
Step-by-step explanation:
The purpose of referring a patient in the first trimester of pregnancy for a serum alpha-fetoprotein test is to screen for certain fetal abnormalities. Alpha-fetoprotein (AFP) is a protein produced by the fetal liver and is present in the mother's bloodstream. Abnormal levels of AFP can indicate the possibility of neural tube defects, such as spina bifida or anencephaly.
The test measures the concentration of AFP in the mother's blood. If the levels are significantly higher or lower than normal for the specific gestational age, further diagnostic testing may be recommended to determine the cause and potential risks to the fetus.
It's important to note that an elevated AFP level does not necessarily mean that the baby has a birth defect, but it does warrant further investigation and follow-up tests.