How to Get a DNA Test Done While You Are Pregnant

Some woman opt for DNA (deoxyribonucleic acid) testing during pregnancy. This type of testing may be used to identify certain genetic diseases and conditions that may occur because of DNA abnormalities, such as Down syndrome. Prenatal DNA testing may also prove helpful for answering paternity questions. Some obstetricians, though, may be reluctant to perform prenatal DNA testing because of the potential risks for the developing baby.

Instructions

1. Ask your obstetrician to help you weigh the risks versus the benefits of prenatal DNA testing. According to the American Pregnancy Association, miscarriage occurs in about one percent of women who have opted for DNA testing through a procedure called chorionic villi sampling; the risk may be less than one percent for women who choose amniocentesis.

2. Request chorionic villus sampling (CVS). For this test, a doctor will thread a fine tube into your vagina or insert a thin needle through your abdomen. The doctor will use this tube or needle to gain a sample of tissue from the placenta--the organ that supports and nourishes the baby, taking it from the area at which the placenta is attached to the wall of the uterus. Since this tissue has the same genetic makeup as the developing baby, a laboratory can use it to test the baby's DNA. An obstetrician may perform this test between week 10 and week 13 of pregnancy.

3. Undergo amniocentesis between week 14 and week 20 of pregnancy. For this procedure, an obstetrician will use a thin needle to reach your uterus through your abdomen. He or she will then remove a sampling of amniotic fluid. A laboratory can test the DNA found in the amniotic fluid, which is the same as your baby's.

4. Expect to experience some discomfort if you opt for DNA testing while you are pregnant. A woman may feel a pinch or prick from the needle used in amniocentesis or CVS. Some women note cramping during and after these tests as well.

Tips & Warnings

• There is a slight risk of infection after prenatal DNA testing. Contact your obstetrician if you develop a fever after testing, as it may be a sign of infection.

• Some women may leak amniotic fluid--liquid that surrounds the fetus--after having amniocenteses. A small amount of leaking is considered normal. Contact your doctor right away if you think you're losing a large amount of fluid.

• You may experience light spotting after prenatal DNA testing. Contact your doctor if it gets worse or seems to be heavier-than-normal spotting.

References

• The American Pregnancy Association: Prenatal DNA Testing
• UMM.edu: CVS
• CPMC.org: Amniocentesis