Getting the right prenatal care is something that should never be taken for granted by pregnant women, and for all the right reasons. During prenatal consultations, you and your baby will be regularly monitored and tested for any potential health problems through prenatal diagnostic tests. Through a prenatal diagnosis, your healthcare provider can determine certain problems with your developing baby, particularly genetic disorders, even before birth.
The purpose of prenatal diagnostic testing
Some parents may be at high risk of bearing a child with a genetic abnormality, which is where prenatal diagnostic tests come to the picture. Certain tests, such as chorionic villus sampling (CVS) and amniocentesis, can help check for fetal defects before birth, helping parents and doctors to create better healthcare decisions for the child. Some problems may be treated even before the baby is delivered, while others may be treated only right after the baby is born.
Unlike prenatal screening tests, the goal of prenatal diagnostic testing is to determine whether the baby has a chromosomal defect. These tests, particularly amniocentesis and CVS, are considered invasive, as they involve inserting a needle into the amniotic sac or the placenta during the developing pregnancy. Since prenatal diagnostic tests are more invasive, they are usually only performed in special cases.
CVS equipment and how it is performed
Usually performed between weeks 10 to 13 of pregnancy, a CVS is a prenatal diagnostic test that may be recommended for high-risk pregnant women with a history of genetic disorders. Your doctor will determine if there is a need to take this test, as not all women has to undergo such procedure.
During a CVS, a small sample of your placenta tissue, which contains chorionic villi, will be removed. Normally, chorionic villi have the same chromosomal makeup as your developing baby. The sample will then be sent to the lab for examination. There are different equipment that may be used during a CVS, depending on the method it is done.
If the CVS is performed through the vagina, a catheter or a thin tube is inserted into the genitalia, passing through the cervix and into the uterus. Throughout the procedure, the doctor depends on ultrasound images to guide the catheter to the correct spot. Meanwhile, the sample can also be acquired using a needle through the abdomen, which will withdraw the placenta tissue. Again, this method involves the help of ultrasound to guide the needle.
What to expect from an amniocentesis
During an amniocentesis, which is usually performed within weeks 14 to 15 of pregnancy, is also another prenatal diagnostic test that helps determine whether the baby has a chromosomal disorder. The test involves inserting a fine needle through the mother’s abdomen and into the amniotic sac to withdraw a sample of the amniotic fluid, which contains cells from the fetus. The sample is then sent to the lab to be examined for their chromosomes.
Amniocentesis also uses ultrasound equipment, particularly an ultrasound transducer, to guide the doctor to the baby’s exact location during the passing of the needle. Unlike another prenatal test called a nonstress test, wherein a toco transducer is used in conjunction with the ultrasound transducer to record uterine contractions, an amniocentesis only involves ultrasound imaging to complement the procedure.
Both CVS and amniocentesis may seem to show similar results, but one may not be able to detect certain things that the other does. For instance, amniocentesis is better at detecting neural tube defects and other birth defects. Meanwhile, a CVS is likely to be recommended if you and your doctor need to know the results as early as the first trimester.
Most women receive normal results on their prenatal diagnostic tests, yet there is no way of truly knowing in the end. While abnormal results may cause a huge deal of stress and anxiety, what is more important is having the opportunity to manage the problem at the earliest possible time.