16 Weeks Pregnant
Almost every mother's fear is that her baby will have some type of problem. Fortunately, most babies born in industrialized countries are healthy. In fact, in the United States major birth defects are rare, occurring in about 2 to 3 out of every 100 births. A birth defect is defined as a mental or physical problem present at birth. Birth defects can be caused by a problem in the baby's genes or because of exposure to a harmful substance during pregnancy. However, in the majority of cases, the cause of the birth defect is unknown.
Your healthcare provider may recommend several tests to look for genetic problems. These include both screening and diagnostic tests. Screening tests help to assess the risk of your baby having a problem. Diagnostic tests allow your healthcare provider to look for specific problems. Doctors usually recommend screening tests before diagnostic tests because screening tests carry no increased risk to the mother or fetus. In some cases, doctors may recommend a diagnostic test in place of a screening test. This may be the case if a woman has a high-risk pregnancy.
Some examples of screening tests your doctor may recommend include:
- A nuchal translucency scan (NT scan) and blood test
- A multiple marker screen, also called a triple screen or quadruple screen (quad screen) depending on how many blood markers are tested
- A cystic fibrosis screening test.
Your doctor may recommend diagnostic tests such as:
- Specialized ultrasound
- Chorionic villus sampling (CVS).
Remember -- even if a screening test reveals an increased risk for a problem, most babies are born healthy.