genetic testing

Genetic Testing During Pregnancy: Prenatal Screening Quick Guide

Genetic testing is an amazing technology that can provide valuable information regarding your current and future health. It involves DNA examination, which is the chemical catalog of your body instructions.  The testing can show unnatural changes in the body that can lead to medical pathology. But if you have thought about getting pregnant, genetic testing during pregnancy can be beneficial to your baby’s health. Some tests can predict diseases in utero. In addition to issues with the unborn child, pretesting can detect future problems by analyzing the mom and dad’s DNA.   However, there are limitations to the diagnosing and prevention tactics of DNA testing. It does not necessarily mean that you or your baby will develop a medical ailment.  

Why Should You Do Prenatal Genetic Screening?

Genetic screening and diagnostic testing when done prenatally can provide information on the health of your baby. The information gained can help parents make decisions during pregnancy and for the future of their baby.  Genetic testing can provide information on hereditary diseases like trisomy 13, Down syndrome, and spina bifida.

With prenatal testing, two types provide information regarding medical disorders. A prenatal screening test will tell you the probability that your baby will have a condition with an abnormal number of chromosomes and a few other disorders.  A prenatal diagnostic test will determine if your baby actually has certain disorders by examining cells from the fetus or placenta. Both types of tests are available to all pregnant moms but are optional.

How Does the Testing Work?

During the first trimester, genetic testing will include testing of the mother’s blood and an ultrasound of the fetus. This process can screen and determine the manifestations of birth defects. Several prenatal blood tests will take place in the second trimester. They are called multiple markers and will tell if the baby is at risk for more birth defects or genetic conditions. At any point during pregnancy, ultrasounds can be utilized for due date estimations, to examine growth, and to look for physical abnormalities.  

You or your baby may be more at risk to be a carrier for certain conditions if you are a member of certain ethnic groups. Cystic fibrosis is found among Caucasians of northern European descent, sickle cell disease among Africans or Asians, and Tay-Sachs among Ashkenazi Jews. If you are in one of these higher-risk categories, you should speak with your doctor. Doctors at the Centers for Disease Control and Prevention (CDC) also recommend screen for vaginal/rectal group B streptococcus at 35 and 37 weeks. But regardless, diagnostic testing and screenings during pregnancy are a personal choice. 

Speaking with your doctor is important because you will have questions regarding what tests you need and also what the results imply. As with any test, there is the risk of a result that is false-positive or false-negative. You could end up believing there is a problem when there is not one, or you could think things are problem-free when a problem does exist. Your doctor can provide consultation on individual test accuracy and interpretation.