Guide to NIPT Tests and Prenatal Testing

Updated May 14, 2019

This article was scientifically reviewed by YourDNA

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When it comes to having a baby, there are many concerns expectant parents have, not the least of which is the fetus' health. During pregnancy, there are a variety of prenatal tests that doctors run routinely and some at the patient's request.

What's in this Guide?

Disclaimer: Before You Read

It is important to know that your genes are not your destiny. There are various environmental and genetic factors working together to shape you. No matter your genetic makeup, maintain ideal blood pressure and glucose levels, avoid harmful alcohol intake, exercise regularly, get regular sleep. And for goodness sake, don't smoke.

Genetics is a quickly changing topic.

At YourDNA, we understand that your concerns are very real, and the information we provide is meant to fully inform you of your choices so you can move forward with peace of mind.

What Are (NIPT) Prenatal Tests?

Throughout pregnancy, expectant mothers will go through several types of prenatal tests.

They're designed to check on the health of both the mother and the baby and help discover potential medical issues prior to giving birth.

What Is Noninvasive Prenatal Testing (NIPT)?

Noninvasive prenatal testing is done without disturbing the fetus or presenting any type of added risk to the mother or the baby. Typically, doctors use NIPT methods of determining risk before moving onto more invasive types that can potentially cause harm.

It's now considered the standard method of testing for genetic disorders due to its high success rate in identifying potential problems early in the pregnancy.

There are different types of NIPT, including screening and even paternity testing. Non-invasive prenatal paternity (NIPP) testing is done through two blood samples: one from the mother and one from the potential father.

Genetic Screening vs Diagnostic Testing

At doctor visits, you'll likely hear the terms genetic screening and diagnostic testing. The two differ in one very important way: telling you whether or not your baby has a specific health condition.

Screening tests are noninvasive and carry no risk. Doctors will collect a few vials of blood and send them off for laboratory testing where the samples will be evaluated for disorders that can cause birth defects or other health conditions that warrant further medical care.

With screening tests, the results are delivered in terms of percentages that determine your risk factors. It's not a definitive answer or a diagnosis.

If the results show an elevated risk factor for your baby having a specific medical condition, your doctor will likely recommend diagnostic testing. This type of testing is more thorough and a bit invasive, as it often requires taking a sample of chorionic villi or amniotic fluid.

Some do pose a risk to the baby, including miscarriage, so it's important to discuss the potential outcomes with your obstetrician and weigh the risk vs benefit.

Why Are Prenatal Tests Important?

Prenatal tests are important because they help identify potential problems with the baby prior to giving birth.

This makes it easy for the expectant parents and doctors to prepare ahead of time if medical intervention is necessary. Prenatal tests can help identify genetic disorders, medical conditions that require immediate attention and birth defects that warrant extra care.

What Prenatal Genetic Tests Screen For

There are a myriad of conditions that genetic tests can screen for, but the most common involve those with chromosomal abnormalities such as Down syndrome, trisomy 18, trisomy 13 and a missing X or Y chromosome.

Carrier status testing can detect whether the expectant mother and father are carriers for disorders such as cystic fibrosis, to determine whether advance planning or more testing is necessary.

Who Prenatal Genetic Testing is For

Prenatal genetic testing can be done for any pregnant woman, though there are circumstances that may warrant a more thorough examination.

For example, doctors may require it for women who are over the age of 35 due to the elevated risk of genetic disorders that comes with these pregnancies.

Additionally, expectant parents who have a family history of genetic disorders and those who are carriers of specific disorders may want to undergo screening to determine whether or not the baby has inherited one or more of them.

If you feel that you want the extra peace of mind that comes with prenatal genetic testing, you can always ask your doctor to run these test. Most will do the noninvasive screening tests at your request.

The lab results usually arrive within a few business days, though you may not find out the results until your next visit.

Benefits and Risks of Prenatal Genetic Testing

Like any type of genetic testing, there are benefits and risks to those administered during pregnancy. The benefits include having the knowledge ahead of time as to whether there's a medical issue that the parents need to prepare for.

Some disorders affect cognitive and neurological function, so having advance warning helps ensure that there are no surprises.

However, despite this upside, there are some risks of prenatal testing to consider as well. The more invasive types of testing such as chorionic villus sampling and amniocentesis, which are used to confirm the presence of a disorder or abnormality, can increase the risk of miscarriage since they take samples directly from the uterus, disturbing the environment.

How Non-Invasive Prenatal Testing Works

Noninvasive prenatal testing is simple. It only requires a blood sample that's collected from the expectant mother.

This is because part of the baby's DNA flows through the mother's blood as well, so lab technicians can isolate it and evaluate it for potential problems.

What Prenatal Tests Do You Get All Through Pregnancy?

Throughout the 9 months of pregnancy, expectant mothers will go through a series of tests, many of which are broken down by trimester.

There are different types of prenatal testing to be aware of, as well.

Before Pregnancy

If you're planning to get pregnant and you're aware of a family history of specific diseases and disorders, you might plan to visit with a genetic counselor to undergo specific carrier screening tests. These results can tell you which disorders you and your partner are a carrier for, if any.

If you're a carrier, it means that you have a genetic mutation or deletion that could potentially be passed down to your offspring. Some disorders, such as cystic fibrosis, require two copies of an abnormality — one from the mother and one from the father — to develop in the offspring.

Knowing if you're a carrier ahead of time can help ascertain the risks involved before you conceive.

Common Tests Administered Throughout Pregnancy

Throughout your pregnancy, you'll undergo common prenatal tests including, but not limited to:

  • Blood pressure
  • Urine
  • Blood tests

Checking your blood pressure is important because it can help catch potentially dangerous medical conditions such as preeclampsia, which can put both the mother and baby at risk. One of the warning signs is high blood pressure, so you'll receive a blood pressure check at every appointment.

Urine tests are typically given at every appointment throughout the pregnancy and are useful for identifying infections of the bladder and kidneys. If there's protein in the urine, that could also be a sign of preeclampsia.

Blood tests help check for specific infections such as sexually transmitted infections (STIs), hepatitis and HIV. Additionally, the blood tests are used to identify your blood type as well as your Rh factor to take steps to prevent Rh disease, if necessary.

Finally, the test can help determine if you're anemic.

Prenatal Tests Done in the First Trimester

During the first trimester, there are specific tests that your doctor will order to ensure you and the baby are healthy. The most common include carrier screening, cell-free fetal DNA testing and an early ultrasound.

Carrier screening helps identify any potential conditions that you may be a carrier of, and possibly pass onto your offspring. It's often done within the first few weeks after discovering you're pregnant.

Cell-free fetal DNA testing is carried out after the ninth week of pregnancy and checks the baby's DNA to see if there are any abnormalities and genetic conditions such as Down syndrome. However, this test isn't always routine.

If you're not a higher risk for passing down a disorder and there's no family history, your doctor may not even order the test unless you specifically ask for it.

However, if the ultrasound shows a defect, it may be suggested by your doctor.

Ultrasounds are usually ordered between weeks 11 and 14. In addition to confirming your due date and how far along you are, the ultrasound can potentially identify stunted growth and other birth defects.

The more thorough ultrasound comes in the second trimester.

Prenatal Tests Done in the Second Trimester

During the second trimester, the prenatal tests become a bit more specialized and include maternal blood screening, glucose screening, an ultrasound and in some cases, an amniocentesis.

The maternal blood screening is also known as a quad screen because it looks for four substances including AFP, estriol, inhibin A and hCG. The purpose of the test is to see if the baby you're carrying is at risk for birth defects.

Glucose screening is important because it measures your blood sugar to see if you have gestational diabetes. It's done between weeks 24 and 28, and involves fasting.

If the initial test comes back negative, you won't have to have another one. However, if it comes back with elevated sugar levels, your doctor will have you do another test that involves drinking a solution and then doing two blood draws, three hours apart.

The ultrasound done around the 20-week mark is to see how your baby is developing. Measurements are taken and doctors will look for noticeable birth defects such as those that involve the heart and brain.

At this point, those who want to know can opt to find out the gender of their baby.

If your doctor suspects there may be a birth defect or genetic disorder, they may order an amniocentesis to confirm. Of course, this is strictly optional because of the risk involved.

Prenatal Tests Done During the Third Trimester

In addition to the regular prenatal tests, the third trimester only involves a group B strep. Because it can be passed onto your child during birth, it's important to test and confirm whether the bacteria is present or not.

If it is, your doctor will put you on antibiotics when you go into labor, to prevent the bacteria from passing. To obtain the sample, the doctor will simply collect fluid from the cervix.

This test is given between weeks 35 and 37.

Can I Take a Non-Invasive Prenatal Paternity Test (NIPP) While Pregnant?

Yes, if you are looking to prove paternity, you can definitely order an NIPP while you're pregnant. Doctors will wait until you're until at least 8 weeks pregnant before administering the test.

This is to ensure that there's enough of the baby's DNA in your blood in order to get the most accurate results.

Reasons Why a Paternity Test While Pregnant Might Be The Right Choice

There are multiple reasons why a person would want to have a paternity test, but the sole purpose is to simply identify who the father of the baby is.

Whether it's to prove that a person is indeed the father if there are multiple partners in question, or to petition for child support, a paternity test can put the parents at ease.

Is NIPP Testing Right for You?

If you cannot wait until the baby is born to prove paternity, then it's a good idea to undergo NIPP testing, as it's noninvasive and will not put the baby or the mother at risk.

How Accurate is Prenatal DNA Testing?

Most DNA tests have been developed to the point that they are 99.9% accurate.

If you're concerned about the results, speak with your doctor about more thorough testing or wait until the baby's born to reduce the risk of harming the fetus.

Can a Prenatal DNA Test Be Wrong?

No test, no matter how reliable, is infallible. There are chances that a DNA test could prove to be wrong, which is why there's always an error rate for false positives.

How Early Can You Do a DNA Test on an Unborn Baby?

The time frame for DNA testing depends on the type of testing, but generally, doctors won't order any tests before the eighth week of pregnancy.

Some recommend waiting until the end of the first trimester when the pregnancy is stable for the best results.

Is Prenatal DNA Testing Safe?

For the most part, yes, DNA testing during pregnancy is safe, especially the tests that don't involve collecting a sample from the uterus.

Even if you have to undergo an amniocentesis or chorionic villus sampling, the risk is minimal, so be sure to discuss all options with your doctor.

How Much Does It Cost to Get a Prenatal DNA Test?

The prenatal DNA or NIPT test cost depends on whether you have it done in the office or through an at-home test.

For genetic testing, your doctor will order the tests and bill your insurance for them. You'll be responsible for a co-pay if you have one.

If you're testing for paternity, an at-home test can run up to $200 where a lab noninvasive prenatal testing done in a lab — the only type that's admissible in court — can run up to $500. If you do an at-home option, just make sure you read several noninvasive prenatal paternity test reviews.

If you decide to go with outside NIPT testing companies, you can be expected to pay into the thousands of dollars as most insurance companies will not pay for it if it's not ordered through your doctor.

Where to Get Prenatal DNA Testing Done

The most reliable place to get your prenatal DNA test carried out is through your doctor's office.

You can request the screening — whether it's for paternity or genetic conditions — at any of your regular checkups. If you're looking for a solution to do a DNA test while pregnant at home, you can find prenatal paternity tests at your local pharmacy or online.

These tests are not admissible in court, however, but they do help if you're looking for personal confirmation.

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