Diagnosis of anencephaly:

The diagnosis of anencephaly may be made during pregnancy, or at birth by physical examination. The baby's head often appears flattened due to the abnormal brain development and missing bones of the skull.

Diagnostic tests performed during pregnancy to evaluate the baby for anencephaly include the following:

• Alpha-fetoprotein - a protein produced by the fetus that is excreted into the amniotic fluid. Abnormal levels of alpha-fetoprotein may indicate brain or spinal cord defects, multiple fetuses, a miscalculated due date, or chromosomal disorders.

• Amniocentesis - a test performed to determine chromosomal and genetic disorders and certain birth defects. The test involves inserting a needle through the abdominal and uterine wall into the amniotic sac to retrieve a sample of amniotic fluid.

• Ultrasound (Also called sonography.) - a diagnostic imaging technique that uses high-frequency sound waves and a computer to create images of blood vessels, tissues, and organs. Ultrasounds are used to view internal organs as they function, and to assess blood flow through various vessels.