NIPT Says Boy Ultrasound Says Girl – Which is Actually Right?

NIPT Says Boy Ultrasound Says Girl – What to Believe?

Can nipt be wrong about gender? NIPT is thought to be around 99% effective when testing after 10 weeks gestation. Testing early can hinder the levels of fetal DNA in mom’s blood making the results less accurate. After 10 weeks these tests are rarely wrong and the reliability of the ultrasound can be from 95% accurate. 

Gender of Unborn Child

Your positive pregnancy test has sparked excitement between you and your partner. You will soon have new responsibilities and a little person who will look up to you for their entire lives. Your attention can quite quickly turn to the gender of your unborn child. 

Nowadays it is a rare occurrence to wait to find out whether you are expecting a boy or a girl. Waiting 40 weeks to buy pink or blue is not for the impatient. Luckily science has evolved allowing expectant parents a sneak peek at what gender they should expect. But can they be wrong? Who would you believe if you are told boy on a NIPT blood test but a girl on ultrasound?

Non Invasive Prenatal Testing 

One of the tests that can be conducted is non-invasive prenatal testing (NIPT). This test checks for abnormalities in your blood. By week 10 your fetal DNA is present allowing doctors to test for abnormalities such as Down’s Syndrome and other genetic defects. This style of DNA testing can detect the chromosomes to indicate whether your baby is a boy or a girl. 

If the ‘Y’ chromosome is found then the test will indicate your baby is a boy. Mom’s DNA is of ‘XX’ so finding a ‘Y’ allele in your blood can mean only one result. If the ‘Y’ chromosome isn’t detected then chances point to you having a little lady. 

Can I Get the Wrong Result?

Being told boy on a nipt blood test but a girl on ultrasound can ignite a collaboration of worry. But how reliable are your blood results?

Well seeing as blood markers are tested then there is only cause for around 1% error when detecting the gender after 10 weeks. Obviously, if you take the test early it can hinder the levels of fetal DNA that need to be tested. 

You can also take the tests yourself and send them off to be analyzed so this in turn can also affect your result. 

If you are in a boy-heavy household, pricking your finger in the at-home kit could be contaminated as your husband/ son can leave their Y chromosomes on surfaces which can transfer to the area of blood where you draw from. That’s right it’s not only their dirty laundry they leave hanging around.

As the kits suggest to sanitize within an inch of your life the chances are slim but can be incorrect on the rare occasion. 

Ultrasound Scan

It has taken 20 whole weeks for you to get to your anomaly scan. During this scan, the sonographer technician will check the baby for any physical abnormalities. It isn’t typical practice in many countries but it’s during this scan they can sometimes see the genitalia indicating whether you are expecting a boy or a girl. 

It is at this appointment you can be left full of confusion if the results differ from your NIPT. 

Can I Get the Wrong Result?

Like the NIPT there are chances your ultrasound can give you a false result. In fact, statistics indicate that ultrasound is between 95-99% accurate. 

Rather than testing blood markers, the result lies in the hands of the sonographer and of course your baby. Your baby needs to cooperate and be in a position where their genitals can be seen. Not only this but the medical professional conducting your scan is human and mistakes can be made. Whether an umbilical cord gets mistaken for a penis or your little one has its legs closed tight there is significant room for error. 

I remembered on my first pregnancy I had a gut feeling I was carrying a boy thinking my initiative was strong. I was unnerved when I was told my baby was a girl. Obviously, I hadn’t taken a NIPT so I was included to follow the result from the sonographer. Luckily she was correct and I welcomed a healthy baby girl into the world but it didn’t help to know that there could be a mistake made.

You may also be faced with stories of ‘My neighbor Karen bought loads of blue and she had a girl.’ As we know there is room for error but choosing which test to trust is dependent on you. 

Comparing Tests

Let’s look at both tests side by side to see how they compare.

Type of gender test	How it’s performed	Statistics	Room for error
Non Invasive Prenatal Test	Blood is withdrawn and the presence of the Y chromosome determines the sex of your baby.	99% accurate	Testing too early Compromised environment
Ultrasound Scan	An abdominal scan is performed giving the trained eye a picture of the genitals.	From 95% accurate	Baby in wrong position Mistaken umbilical cord Genitalia may not be pronounced enough for a clear scan result

Wrapping Up

There can be times when your nipt says boy ultrasound says girl. Consider the time frame where you took your NIPT if you were not yet 10 weeks then results can be hindered. This can sometimes only be detected after your dating scan so make sure your dates work out for a genuine result. 

A NIPT tends to leave less room for error whereas an ultrasound has more factors to give you an inconclusive result. 

You will come across Karen’s whose gender was incorrect but only time will tell to see which test was correct for you.

More to Read:

• Hair on Ultrasound vs When Born: Everything You Need to Know
• Can An Internal Ultrasound Be Wrong and Harm My Baby?
• Why Do Babies’ Lips Look Big in Ultrasound?