Before You Get Pregnant

• If you are in a relationship and are thinking about having a child together, it may be wise to go in for some prenatal genetic testing prior to getting pregnant. Prenatal testing can give you a clearer picture of what your baby's chances of being born with a birth defect are. You will fill out health questionnaires and do blood tests to determine the risks. Usually the prospective parents have a reason for getting prenatal genetic testing done, such as:
  -One of the parents has a close family member with a genetic birth defect or disorder.
  -The prospective parents are first cousins or close blood relatives.
  -The mother has had several miscarriages or a stillbirth.
  -You already have a child with a genetic birth defect or disorder.
  -You have been exposed to radiation or chemotherapy.
  -You have a genetic disability or disorder.
  -The mother will be over 35 when the baby is born.
  
  Depending on the results of your test, you may choose not to have children.
  
  

Genetic Tests

• If you are already pregnant, genetic tests can be done to see if the developing baby has a high or low risk of being born with a genetic disorder or defect. Maternal serum screening is a blood test offered to all pregnant women. This test, which is completely optional, will determine if the developing baby has an increased risk of having one of three disorders; neural tube defect, Down syndrome or trisomy 18.
  
  Neural tube defects occur when the spinal cord does not completely close and the baby is born with varying degrees of paralysis or anencephaly. Anencephaly is fatal.
  
  Down syndrome occurs when a baby has an extra copy of chromosome 21. Children born with Down syndrome have varying degrees of mental retardation and possible heart and other physical defects.
  
  Trisomy 18 occurs when the baby has an extra copy of chromosome 18. The baby is born with severe mental retardation and heart defects. The baby will usually not live past the first year.
  
  

Test Results

• It's important to understand that once you have the test done, no matter what the result is, it does not mean for sure that your baby has one of these birth defects. Your test results may come back that your baby has a low risk of having a defect and you will not be offered any more genetic tests. If the test results come back that your baby has a high risk, more tests such as an amniocentesis, will be offered. A high-risk test result still does not mean your baby has one of the defects. For example, according to the March of Dimes, "Out of every 100 women who take the screening test, about 5 percent have an abnormal result but only 4 to 5 percent of women whose test results show an increased risk for Down syndrome actually have a baby with Down syndrome."
  
  

Amniocentesis

• Amniocentesis is the next test that can be done to determine if the baby has a birth defect. The test involves taking a sample of the amniotic fluid with a thin needle. The amniotic fluid contains cells from the baby and can be tested for the defects. This test is 98 percent accurate in determining Down syndrome, trisomy 18 and neural tube defects.
  
  

Benefits of Knowing

• Once you have your test results you can become educated and prepare for a baby with one of these disorders or decide to end the pregnancy. If you decide to have the baby, your doctor will prepare a team of experts to be ready when your baby is born.