5 myths about pregnancy-related genetic testing and counseling

Genetic counseling can offer information at all stages of growing a family. While we do see many patients who are already pregnant, a large number of our patients here in the Genetics and Pregnancy clinic come after delivery or while they are preparing for pregnancy.

Before pregnancy, many patients see a genetic counselor to discuss their family history or options for carrier screening. Using a blood or saliva sample from the parents, we analyze their DNA to estimate the chances their child could inherit a genetic condition such as sickle cell disease, cystic fibrosis, or spinal muscular atrophy. While carrier screening is highly accurate, the results can be confusing. A genetic counselor can help explain what the results mean for your future children.

Many people also seek genetic counseling during the process of in vitro fertilization (IVF), particularly if they are planning on genetic testing of embryos. Embryo testing, or preimplantation genetic testing (PGT) can be used to select embryos that are unaffected with a hereditary disorder that runs in the family or can help identify embryos that will be most likely to result in a healthy pregnancy. Preimplantation genetic testing does not screen for every genetic variant; it screens for specific variations in chromosomes or genes that could result in a congenital condition or miscarriage.

Genetic counseling is optional. It is your decision to get it, and you can use the information we provide in the way you feel is best. Some parents want to know as much information as possible about their pregnancy and baby before delivery. Others wish not to know anything further than the most basic information. Either option is 100% your choice, and we will respect and support you in your decisions.

For starters, NIPT results can be confusing. Many doctors refer prospective parents to genetic counseling if results indicate risk for an abnormality. If NIPT shows a high risk for a certain disorder, we will need more information to make a diagnosis. Some parents prefer to wait until the baby is born. For those who want more information, prenatal genetic testing can help.

Genetic counselors can also help shed light on risks associated with future pregnancies. If your child is at risk for or diagnosed with a genetic condition, we can connect you with resources for support, referrals to specialists, and networking with other families.

Sometimes, genetic counselors have difficult conversations with patients. Getting results from a screening can be stressful, especially if the results show a pregnancy is at risk. But often, we have positive conversations that give families peace of mind.

This can include explaining terminology, such as “variant of uncertain significance,” which means a genetic variation is present but the medical implications aren’t clear. We can also clear up false positives, which is when a screening suggests the risk of a condition but is found later to be incorrect.

Genetic counselors can also help patients understand the level of risk associated with a variant, such as MTHFR gene mutations, which are very common and have been inappropriately associated with recurrent miscarriage – no peer-reviewed study has validated this connection.

And when diagnostic testing confirms whether a child will or will not have a specific condition, we are there to support families through their next steps. Genetic counselors are providers of information, and we are here to answer difficult questions with honest, compassionate answers. Often, people leave a counseling session feeling relieved and more prepared to welcome their new baby.

Genetic testing can offer expectant parents a window into the health of their new child, but it’s not a crystal ball. And just because you’ve had one genetic test doesn’t mean you’ve learned all there is to know.

There are many different types of genetic testing, and they do not screen for the same conditions. A simple blood test that can screen for fragile X syndrome may not also screen for risk of chromosomal conditions such as trisomy 18 or Down syndrome.

Some conditions, including autism, do not have a genetic test available. More than 100 genes and over 100 chromosome differences are thought to be behind autism, and there is no one gene mutation that leads to autism 100% of the time.

Talk with your prenatal care provider and a genetic counselor about the conditions or variants you are concerned about. Together, we can determine whether a genetic test or screening is appropriate and help you through the next steps to get the information you need.