prenatal diagnosis, any of various diagnostic techniques to determine whether a developing fetus is affected with a genetic disorder or other abnormality. Such procedures as radiographic examination and ultrasound scanning can be used to follow fetal growth and detect structural abnormalities; amniocentesis enables fetal cells to be obtained from the amniotic fluid for culture and biochemical assay for detection of metabolic disorders and chromosomal analysis; fetoscopy enables fetal blood to be withdrawn from a blood vessel of the placenta and examined for disorders such as thalassemia, sickle cell anemia, and Duchenne’s muscular dystrophy. If any of the test results are positive and the child is likely to be born with a severe defect or disease, the parents need support and advice from genetic counselors on whether to terminate the pregnancy. If the parents decide to have the baby, the members of the health care team can help educate them about the specific disorder and prepare them for the special care required of a child with a disabilty or genetic abnormality. Also called antenatal diagnosis. See also chorionic villus sampling, genetic counseling, genetic screening.
