13 Weeks Pregnant Ultrasound: Nuchal Translucency Scan

The 13 weeks pregnant ultrasound (also called the NT Scan or Nuchal Translucency Scan) is one of many prenatal appointments and doctor’s visits that pregnant women have in the early stage of pregnancy.

This specialized ultrasound is performed by an MFM (maternal-fetal medicine specialist) in conjunction with a blood test. 

The results of the test will tell you whether your baby is at high risk for chromosomal abnormalities. 

What is the 13-week ultrasound? mommymakerteacher.com Ultrasound image from first trimester.
What Is The 13-Week Ultrasound?

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When Is The NT Scan Done?

The Nuchal Translucency Scan is an early ultrasound performed at the end of your first trimester or beginning of your second trimester, between 11 and 13 weeks of pregnancy.  

The NT Scan is sometimes called the 12-week scan or first-trimester scan.

Due to the baby’s development, the test cannot be performed be before or after this time. 

It is important to recognize early pregnancy symptoms, and know how to calculate your due date so that you don’t miss out on the testing window for the NT Scan. 

How Is The 13 Weeks Pregnant Ultrasound Performed?

Unlike your first ultrasound (your dating ultrasound) which is a transvaginal ultrasound, the 13 weeks pregnant ultrasound is transabdominal: an ultrasound probe is used with a gel directly on your belly. 

The ultrasound machine uses sound waves to create a picture of what is going on inside your belly. 

You will need a full bladder for this ultrasound examination. You will drink between 16 and 32 ounces of water, 30 minutes before your scheduled ultrasound. 

Make sure you follow the directions that you are given for eating and drinking prior to the appointment exactly because you might have to reschedule otherwise. Since the window of time for this scan is so short, you’ll want to avoid having to reschedule.

Mom Tip: I personally find the 13-week ultrasound scan the hardest because you aren’t supposed to eat before it and you have to drink water. This is really tricky to do if you have morning sickness! My best advice is to schedule the appointment for the time of day when you are usually the least nauseous.

In addition to the ultrasound, you will also have blood drawn and sent to a lab. The combination of the bloodwork and ultrasound will give the most accurate results. 

What Does the 13 Weeks Pregnant Ultrasound Screen For?

The Nuchal Translucency Scan screens your baby for chromosomal abnormalities.  

The test will tell you whether your child is at a higher risk for certain genetic conditions like: 

What Is The Nuchal Translucency?

The nuchal translucency, or nuchal fold, is the area of fluid behind the baby’s neck. The ultrasound technician will measure the thickness of the fluid. The thickness of the fluid is a good indicator of chromosomal abnormalities. 

Diagram of the nuchal fold

What Is A Normal Nuchal Translucency Measurement?

The normal measurements for the nuchal translucency are up to 2mm for gestational age of 11 weeks, and up to 2.8mm for gestational age of 13 weeks 6 days. 

Screening Test Versus Diagnosis Test

The 13 weeks pregnant ultrasound is only a screening test, not a diagnostic test.  

A screening test tells you whether your baby is at an increased risk for one of the above conditions, it cannot tell you whether your baby definitely has it or not. 

Based on the results of the scan, you will determine whether you want additional testing done. 

If your NT Scan comes back with a high risk for chromosomal abnormalities, your healthcare provider will talk to you about diagnostic tests like chorionic villus sampling (CVS) or amniocentesis

These are diagnostic tests that will tell you whether or not your baby has one of the following conditions. Both of these tests are invasive and come with risks to the pregnancy, so consulting with your health care provider and getting all of the information beforehand is critical. 

Should you do the 13-week ultrasound? mommymakerteacher.com Ultrasound image from first trimester of pregnancy with nuchal fold circled.
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Do I Have To Have A 13 Week Ultrasound?

No, you do not have to have a 13-week ultrasound. This is an optional screening test. Many expectant parents choose not to have the 13-week ultrasound performed. You should strongly consider the NT Scan if you are at higher risk of having a baby with a chromosomal abnormality. 

Discuss your medical history with your doctor to find out if you are at higher risk. Some risk factors include: 

  • Your age
  • A family history of any of the conditions 
  • Previous pregnancy with a positive diagnosis for any of the conditions 

Other Information For The 13 Weeks Pregnant Ultrasound

The 13 weeks pregnant ultrasound is an in-depth look at the baby’s growth up until that point, in addition to measuring the nuchal fold. Don’t be surprised if the ultrasound lasts 40 minutes or longer. The technician will be examining the baby’s growth and development in detail.

The ultrasound technician will: 

  • Confirm the baby’s weeks gestation 
  • Check for fetal development 
  • Measure amniotic fluid
  • Listen to the baby’s heartbeat
  • Check the umbilical cord
  • Take measurements of the baby
  • And more

Your baby’s fetal anatomy is really starting to take shape at this point. Your baby will look more like a baby and less like the gummy bear they did at the 8-week ultrasound. 

You will be able to see your baby move, and you might also see some facial features like the eyes and nose. 

Your technician will send you home with an ultrasound picture.

Pro Tip: Don’t forget to keep a pregnancy journal to store your first ultrasound picture, your bumpies, and your memories of pregnancy. 

Your Pregnancy At 13 Weeks

Here are a few highlights of what else is going on with your baby and body at the end of your first trimester.

By now you should have had your first prenatal appointment. You should be taking a daily prenatal vitamin with folic acid to promote a healthy pregnancy.

At 13 weeks, your baby is about the size of a lemon, plum, or peach… A little over 2.5 inches long and weighing just under an ounce. Their eyes have developed, but are still shut. They are also developing their vocal cords and nervous system.

If you were suffering from morning sickness, the good news is that you should start feeling better soon. Although a few of us unlucky mamas (myself included) will continue to feel sick well into the second or even third trimester 🤢.

You might have noticed a little weight gain. This is perfectly normal and to be expected as you eat extra calories to fuel your growing baby. When you are going through morning sickness, the important thing is just to eat and drink as much and as often as you can. As you start to feel better you can focus on a more balanced diet rich in protein and green leafy vegetables.

…Although those food cravings will be kicking into full gear! Go ahead mama and treat yourself every once in a while!

It’s a good idea to start strengthening your pelvic floor muscles for an easier delivery. I personally used Every Mother to heal my diastasis recti after my first, and tone my pelvic area during my second pregnancy.

If you haven’t already, now is a good time to start reading up on pregnancy, your developing baby, birth, and what to expect when your little one arrives. Gather as much information as you can now because your pregnancy will go by so fast! Here are the books that I recommend for moms. Dads, don’t think I forgot about you! Here are my favorite pregnancy books for dads.

Pro Tip: You can get 2 of these books (or any of your pregnancy favorites) for FREE–no strings attached–by starting a free trial of Audible audiobooks. Audiobooks are even better than traditional books for busy mamas because you can listen while you exercise, drive, run errands, and more.

Finally, you should be thinking about things like your baby shower and the baby gear that you are going to need in the upcoming months.

Upcoming Doctor Appointments And Ultrasounds

The 13 weeks pregnant ultrasound is one of 4 routine prenatal ultrasounds that you will have. 

The next ultrasound will be the 20 week anatomy scan. The 20-week ultrasound is very exciting if you want to know the sex of your baby. 

If you want to learn more about the other ultrasounds, what they test for, and the other prenatal doctor’s visits you are going to have, read my detailed guide on doctor’s appointments during pregnancy

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