Definition - What does Alpha-Fetoprotein (AFP) mean?
Alpha-fetoprotein (AFP) is a protein produced by the unborn fetus. During pregnancy, high or low levels of this protein, which can be detected in the woman's blood, is measured and used as a screening tool to detect various fetal abnormalities. It is routinely measured between the 16th and 18th week of pregnancy.
FertilitySmarts explains Alpha-Fetoprotein (AFP)
During pregnancy, alpha-fetoprotein is created in the fetal liver and then excreted into the woman’s blood. These levels can be used to screen for various birth defects within the fetus. For example, low levels of AFP can be indicative of chromosomal abnormalities such as Down’s syndrome (Trisomy 21) while high levels may be seen in spinal abnormalities such as spina bifida or deformities of the intestine and abdomen.
High levels may also be seen in twin pregnancies and situations where there is an error in the pregnancy dates. Once there is an abnormality detected in the AFP levels, further testing, such as ultrasound or amniocentesis (where a sample of amniotic fluid is tested) is performed fur further investigation