APA Dictionary of Psychology

the irregular development of a fetus, often discovered via prenatal testing (e.g., amniocentesis, chorionic villus sampling). Some fetal abnormalities have a genetic basis (e.g., Down syndrome); some are caused by maternal behaviors (e.g., fetal alcohol syndrome); and others may have a combination of genetic, nutritional, and environmental causes (e.g., spina bifida and other neural tube defects). See also congenital defect.