After becoming pregnant, many people’s thoughts turn to how to prepare for the baby’s arrival, both mentally and medically. There are a number of prenatal screenings and tests that can be performed to help both expecting parents as well as their doctors construct a robust, personalized care plan for pregnancy and childbirth.

One such screening is used to identify the baby has the typical number of chromosomes, 46, or if there might be a chromosome imbalance, known as  aneuploidy. If a chromosome imbalance is detected, that  can lead to conditions that can affect childbirth or the baby’s life after birth.

What is Aneuploidy?

As explained by board-certified medical geneticist Dr. Tamar Goldwaser, “Aneuploidy means that a human being has a different number of chromosomes than what you would have expected.” What’s expected is that people get 23 chromosomes from their mother and another 23 from their father for a total of 46. Aneuploidy occurs when there are either more or fewer chromosomes than expected.

Aneuploidy causes a variety of genetic conditions, although the most well-known condition is Down syndrome, which occurs when there are three copies of chromosome 21. For this reason, aneuploidy screening is sometimes referred to as “Down syndrome screening,” although the genetic testing in reality checks for much more than just Down syndrome.

Why Screen For Aneuploidy?

Like many other prenatal tests, aneuploidy screening and follow-up diagnostic testing, gives important information to expectant parents and allows for  time to prepare, make decisions, and ensure their baby will get the best care. Prior to tests such as this, Dr. Goldwaser counsels patients to help them understand what results they might receive. In some cases, a severe condition may be detected.

Having this information will provide families with the opportunity to consider all options. Some start by talking with various specialists, spiritual advisors, family and friends, and some use the time to become educated and seek out specialists to care for a baby with special needs. Sometimes, families make the difficult decision to  terminate the pregnancy.

When patients undergo screening for aneuploidy or for other genetic conditions, they are usually comforted by the “low risk” or “normal” results. However, any woman who elects to have this screening might get unexpected or high-risk results which would then prompt a consultation with a specialist.

Genetic information from screenings helps drive parents’ preparation for childbirth, including where they may need to deliver the baby, what experts or surgeons to have on standby, and even where they may want to move to have access to certain schools and services.

It’s worth mentioning that genetic testing and aneuploidy testing are not always required as part of a person’s prenatal care regimen. Many people who are pregnant don’t want to know ahead of time whether their baby has a condition such as Down syndrome—it’s a perfectly reasonable position to find out at birth how they’ll care for and love their child, no matter what conditions they may or may not have.

Being Prepared With Prenatal Genetic Testing

Dr. Goldwaser says “Even if you go all the way, and check for as many conditions that are available, we always take a step back and say, ‘There’s no such thing as a perfect baby, there’s no such thing as 100%. We cannot test for every condition that a baby or child might have. . . . Having a baby will always require some leap of faith.”

Aneuploidy Testing Options

Today, there are numerous tests, some invasive and some non-invasive, to test for both the number of chromosomes and the possibility of aneuploidy in a developing fetus. Ultrasound imaging is often the first approach for all kinds of fetal health indicators, including brain, spine and heart anatomy, stage of development, number of fetuses and placentae, and more.

If ultrasound or other non-invasive prenatal testing indicates there may be a structural or genetic issue, two invasive and diagnostic tests to consider would be amniocentesis or chorionic villus sampling (CVS). The samples obtained in these tests allow lab technicians to look into the cells and count the number of chromosomes. A further analysis called micro-array can help identify key segments of DNA that are known to be the source of genetic disorders and check whether there’s an addition or deletion that would lead to a disorder.

Genetic Testing for Aneuploidy in New York City

The risk for any specific pregnancy to be affected by a genetic disorder such as aneuploidy is low, but not zero. The conditions that arise from these abnormalities can be serious and can change the course of pregnancy care for people who choose to undergo testing. With over a hundred different potential disorders arising from extra or missing DNA, this can lead to deeply difficult decisions that our team is well-prepared to help parents walk through with compassion and expertise.

If you want to know as much as possible about your baby’s health with prenatal screenings for conditions such as aneuploidy, Maternal Fetal Medicine Associates can help. Our geneticist, Dr. Tamar Goldwaser, along with our caring team of maternal fetal medicine specialists, will work with genetic counselors to help you navigate whatever the results of your prenatal screenings show and help you make the decision that’s best for your family both in the moment and in for the long run. Get in touch with us today by calling our upper east side office or contacting us online today.