13 Weeks Pregnant Ultrasound: Nuchal Translucency Scan

The 13-week pregnancy ultrasound (also called the NT Scan or Nuchal Translucency Scan) is one of many prenatal appointments and doctor’s visits you’ll have during your pregnancy. It’s an optional test to tell whether your baby is at high risk for chromosomal abnormalities.

ultrasound picture highlighting the nuchal fold at the 13 week ultrasound

When Is The NT Scan Done? 

The Nuchal Translucency Scan is done between 11 and 13 weeks. This is at the end of your first trimester or the beginning of your second trimester. 

TIME SENSITIVE: This test is time-sensitive and cannot be performed before or after this time. It is important to recognize early pregnancy symptoms and know how to calculate your due date so you don’t miss out on the testing window for the NT Scan. 

What Does it 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 to Expect at the Test

Before the Test

  • Drinking: This ultrasound examination requires a full bladder. You will drink between 16 and 32 ounces of water 30 minutes before your ultrasound. Follow your instructions for how much water to drink and when.
  • Eating: Make sure you follow the directions that you are given for eating and drinking before the appointment precisely because you might have to reschedule otherwise. Since the time window for this scan is so short, you’ll want to avoid rescheduling.

Mom Tip: I find the 13-week ultrasound scan the hardest because you aren’t supposed to eat before it and must drink water. This is 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.

During the Test

This specialized ultrasound is performed by a Maternal Fetal Medicine (MFM) specialist. Typically, this test will be performed at a different location than your usual ultrasounds.

  • Transabdominal Ultrasound: It’s done directly on your belly. The ultrasound machine uses sound waves to create a picture of what is going on inside your uterus.
  • Your Baby: Your baby’s fetal anatomy is taking shape by this screening. They will look more like a baby than at your first ultrasound! Enjoy watching your sweet child swim around. You might even see some facial features like the eyes and nose.
  • Don’t be surprised if the ultrasound lasts 40 minutes or longer. The technician will:
    • Confirm the baby’s weeks of 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
  • You’ll get lots of cute ultrasound pictures to take home.

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

After the Test

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. 

You’ll discuss the results with your healthcare provider after the bloodwork returns (typically a week or two).

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

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 nuchal translucency scan is only a screening test, not a diagnostic test. It can tell if your baby is at an increased risk for one of the conditions listed above, but it cannot tell whether they have it.

The normal range for the nuchal fold is less than 3mm. Your doctor will recommend additional tests if your abnormal result exceeds 3mm. Follow-up testing may include:

These diagnostic tests will tell you whether or not your baby has a genetic condition.

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How Soon Can A Doctor Tell If You’re Pregnant?

6 Super Helpful Books To Read During Pregnancy

39 Best Pregnancy Books For Dads And Expectant Fathers

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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 as it will not change the pregnancy outcome.
  • Many choose to have the NT scan to be prepared in the event their child will have special medical needs.

You should strongly consider the NT Scan if you are at higher risk of having a baby with a chromosomal abnormality. Your OB can counsel you on your 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 

Your Pregnancy At 13 Weeks

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

At 13 weeks, your baby is about the size of a lemon, plum, or peach… It is a little over 2.5 inches long and weighs 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 ?.

It’s a good idea to start strengthening your pelvic floor muscles for an easier delivery. After my first pregnancy, I started Every Mother to repair my ab separation. For my second, I learned they have a prenatal program to tone your pelvic floor.

If you haven’t already, now is a good time to start reading up on pregnancy, your developing baby, planning your baby shower, and what to expect when your little one arrives.

Jacqui headshot



I am the founder of Mommy Maker Teacher and a mom of two toddlers. With a degree in education, 12+ years of experience as a K-12 teacher and curriculum developer, and courses in childhood psychology and language acquisition, I share research-backed parenting tips and advice. I provide helpful content for moms on all stages of motherhood—from trying to conceive and pregnancy to postpartum, breastfeeding, and parenting.