Your 12-Week Ultrasound: Everything You Need to Know

I had no idea what to expect when it came to my 12-week ultrasound.

Even though I was excited to finally see an image of my daughter, I was also terrified about the possibility of finding out something might be wrong with her.

So, on the day of the scan, I found myself sitting in the waiting room trying my best to occupy myself with magazines, social media or anything else I could get my hands on.

Finally, my husband and I were called back and the ultrasound started. Within seconds, we saw our baby girl on the screen and as I had anticipated, she was the most beautiful thing I had ever laid my eyes on.

However, as I laid there, I couldn’t help but wonder what they were looking for, if the ultrasound was actually safe for myself and my baby, and whether or not I was going to find out the results that day. Curious, I asked the technician a few questions about the ultrasound but she was so preoccupied with measuring my baby that she couldn’t give the detailed explanations I was hoping for.

Fifteen minutes later, the ultrasound was finished and my husband and I were relieved to find out that our daughter was 100% healthy.

But, even though I was happy with my results, I couldn’t help but wonder why we have a scan at this time in pregnancy, whether or not it’s safe and what the indicators of a healthy baby are?

This curiosity is what lead me to reach out to Dr. Camille Hoffman, a Maternal Fetal Medicine physician at the University of Colorado to find out everything there is to know about the 12-week ultrasound.

I hope that Dr. Hoffman’s answers leave you feeling informed, empowered and confident in your decisions when it comes to your 12-week ultrasound.

Who are you and what do you do?

1. I'm Camille Hoffman. I am a Maternal Fetal Medicine physician which means that I am an obstetrician who focuses on the management of women with high-risk pregnancies. I live in Golden, Colorado and work for the University of Colorado.

Can you give us a brief description the 12-week Nuchal scan?

2. The 12-week ultrasound usually occurs between 11 and 12 weeks. What we look for during the ultrasound is how many fetuses there are and if there’s any evidence of early predictors of a chromosome problem or a birth defect, which we call anatomic abnormalities. In general, we look for any signs that pregnancy is off to a good start or potentially not off to a good start.

When a woman comes in for her 12-week ultrasound, what can she expect?

3. She can expect to have an ultrasound across her abdomen. Since the fetus is now big enough, the ultrasound can be done through the mom’s belly rather than transvaginally like she may have had done earlier on in her pregnancy. 

What are you specifically looking for in the scan?

4. Initially we look to see where and how the placenta is forming, if there’s a normal amount of amniotic fluid and how the fetus looks. We look at the major features in the brain, the heartbeat and the skeleton, and we see if there are two arms, two legs, and if the umbilical cord is going into the future belly button.  However, the main thing that we do during this ultrasound that can’t be done during other times in pregnancy is what’s called a measurement of the nuchal translucency, also known as NT. NT is a little sliver of fluid at the back of the baby's neck in-between the spine and the skin. If that area is enlarged, which is uncommon but part of the purpose of this ultrasound, then it can be predictive of a chromosome problem, a small genetic problem or some kind of anatomic problem.

What are the indicators of a healthy pregnancy that you’re testing for?

5. The indicators of a healthy pregnancy are normal-looking amniotic fluid, a placenta that’s forming in a good location and a fetus that measures according to what you think the due date is. Also, two arms, two legs, normal looking skull and normal looking spine, as well as a good measurement of the nuchal translucency. Those are all indicators that things so far are going just fine. 

Okay, as you mentioned, it's not just 12 weeks, it’s anywhere between 11 to 13. Can you talk about why it’s that exact window?

6. It's actually based on the measurement of the crown rump length, the measurement of a fetus from the crown of it’s head to it’s bottom “rump” area. These scales were developed to determine what the norms were for that nuchal translucency measurement. So this is all based on a crown rump length of 45 to 84 millimeters, which usually translates to a pregnancy that's about 11 weeks 0 days to 12 weeks 6 days.

When do you find out the results to your test?

7. Right away. The Maternal Fetal Medicine physician, obstetrician or whomever was doing the ultrasound at that time will come in and discuss the results with you.

A lot of women in our community are concerned about the negative effects that ultrasounds can have on a fetus. Can you speak to that concern and if there are any negative side effects?

8. All ultrasound machines use what we call the ALARA Principle “As low as reasonably achievable.” This means that every ultrasound is set to not go above certain thresholds, ensuring that a fetus will not be exposed to an excessive amount of ultrasound waves.  For example, in cases where they use ultrasound to deteriorate fibroids, the probes are set to a much higher frequency and require a lot of time spent over a certain area that doesn't move to actually deteriorate the fibroids. So, when you think of a little fetus that's moving around… not only is the frequency not high enough to harm your baby, but you couldn't even stay over the same area because the fetus is constantly shifting. So yes, ultrasounds are safe for you and your baby.

About our Expert

Camille Hoffman, MD, MSCS, is an Associate Professor of Maternal Fetal Medicine in the University of Colorado School of Medicine Departments of Obstetrics & Gynecology and Psychiatry.  She is a clinician-scientist who studies the impact of perinatal stress on pregnancy outcomes and on maternal-child mental health. Her current research focuses on pregnancy interventions to improve multigenerational mental health.  She serves as Principal Investigator or co-investigator on several federally and privately funded research grants. Her research was featured in a Rocky Mountain Public Broadcasting System documentary on health disparities in infant mortality entitled “Precious Loss.”  Dr. Hoffman has clinical expertise in the management of high-risk pregnancies, obstetric ultrasound, and perinatal mental health.  She is a founding board member of the Marcé Society of North America and also serves as the social media director for the International Marcé society for Perinatal Mental Health.   Dr. Hoffman completed medical school at the Medical University of South Carolina, Obstetrics & Gynecology residency at the University of Miami, and her Maternal Fetal Medicine fellowship at the University of Colorado.   She recently completed a fellowship in Integrative Medicine through the University of Arizona. She lives in the Rocky Mountain front-range with her husband, two children, many bicycles and a menagerie of farm animals.  

Pregnancy can be a time of great excitement but also one filled with a lot of uncertainty, especially when it comes to things like testing. It’s my hope that providing education around the 12 week scan during this interview with Dr. Camille Hoffman helps you to feel empowered throughout their pregnancy and informs you of their choices when it comes to their maternal health.