Pregnancy can be an exciting time for expectant parents. It can also be a time of concern over the health of the baby. Medical technology has led to the development of many prenatal screening tools used to identify mothers and babies who are at an increased risk for developing a disease or condition.

Prenatal screening results may not give a “yes” or “no” answer about the presence of a disease or whether it will develop, but if it is more or less likely. Women or fetuses with a positive screening test may not actually have or develop the condition (false positive) or may develop the condition even if the screen is negative (false negative). The screening may only identify those at high risk.

Birth defects are physical abnormalities that may be caused by inherited genes, genetic mutations, or environmental factors. They cause deformities or disabilities that cannot always be treated or cured. Birth defects that are most often identified by screenings are chromosome abnormalities like Down syndrome and neural tube defects like spina bifida.