Tell me about AFP testing plz?

AFP. Afp, or Alpha fetoprotein, is a fetal protein that is used to screen for the presence of neural tube defects. Higher levels of AFP are seen in mother's blood and amniotic fluid when a baby has an open neural tube defect. The test is done in the second trimester of pregnancy. AFP is also used as a tumor marker for some hepatic cancers. Following AFP levels could alert doctors to tumor recurrence.