October is Ultrasound Awareness Month. Because 60-70% of HLHS cases are diagnosed in utero by ultrasound, the ultrasound sonographer often plays a crucial role in a family’s HLHS journey. I sat down with Kate Praska, RDMS, an obstetrics (OB) sonographer at Mayo Clinic who has 30 years of experience. While she primarily performs routine OB ultrasounds, she’s also board certified in fetal cardiac echocardiography. Below, she shares her thoughts on ultrasound technology, how the job has changed, and her connection to her patients.
Below is Part I of our interview -- check back later this week for the concluding Part II!
Hi Kate, thanks for talking with me! Can you start by giving us an overview of fetal ultrasound? When is it done, what do you look for, what’s the process like?
Sure. While ultrasound can be used in a pregnancy as early as about 5 weeks gestation, the first scan is usually done in the first trimester around 7 weeks for dating, and the anatomy scan is done at 18-20 weeks. That scan is the most important because it’s essentially “baby’s first physical.” We do a very detailed evaluation of all anatomical structures to make sure the baby and pregnancy are progressing normally. At our site, we have been implementing a first trimester anatomy scan to evaluate for any large fetal defects.
If everything looks good and there are no other concerns, then patients might not have another ultrasound. So it’s incredibly important that we get a good look at everything during that visit.
What happens if you see something that doesn’t look right?
First and foremost, it makes me look at things more thoroughly. If I’m scanning and the heart looks funny, I’m going to look at everything that I possibly can on that baby. If I see a definitive heart defect, I tell the patient and then tell them I’m going to have the high-risk doctor come in and speak to them. The doctor comes in and talks to the patient, and then we call Cardiology to get them in for an echocardiogram as soon as possible.
Patients might get a little worried when I tell them we want to take a closer look at something, but I don’t want them to have a concern that we missed something or send them home thinking everything is perfect. I also want them to start preparing and thinking of questions to ask the doctor.
At some smaller clinics, the sonographers aren’t allowed to tell the patients anything, and they instead have to contact the obstetrician and have them arrange follow-up. Our clinic is an OB/Maternal Fetal Medicine department that has all high-risk specialties readily available to care for the patient (MFM doctors, nurses, genetic counselors, etc.). In the case of heart defect, we often times can get the patient in for a fetal echocardiograph that same day. But even if they can’t get in for an echo that day, that’s ok because they can usually see them within a few days. This gives them time for further testing and they can think about more questions, or make sure their significant other is there or bring an additional person so they have more sets of ears.
Most people can’t tell a head from a foot in an ultrasound. How hard is it to see HLHS in utero?
We can sometimes see it at the 20-week scan if we get a good picture. The best way to describe a lot of heart disease is that it’s “progressive.” For instance, I could scan a patient at 16 weeks and the heart could look normal. But sometimes it’s caught later as the rest of the heart is growing and one part isn’t. There are also some defects that don’t show up until the third trimester. Other times, a baby goes in for its three-month check-up, and they hear a heart murmur. Now, if they hadn’t seen it when the baby was a newborn, imagine us looking back at 20 weeks gestation.
There was one particular baby with HLHS that I scanned a few years ago. It was around 19 weeks and the four heart chambers all looked fine, but I just had an odd feeling. There was one view where the left outflow tract, which becomes the aorta, ballooned out a bit as it came out and the mitral valve seemed a little bright. I just didn’t feel comfortable, so I asked the high-risk doctor who suggested doing a fetal echocardiograph, and they were able to diagnose the HLHS.
Our policy now is that we only let one other person in the room during the scan. I’ve worked at places where they allowed more than one person, and if there are a lot of people, the room gets loud, and the mother might be turning her body to visit with relatives and laughing. Some people think it’s rude that we don’t allow more guests, but if I missed something on a baby, I would honestly feel horrific. It’s a medical procedure to thoroughly evaluate the fetus, mother, and pregnancy, and we need to be sure we can concentrate and do our job well.
Does diagnosing HLHS or other conditions in utero change the course of prenatal care?
Yes, and that’s why I’m very passionate about the heart in particular because early diagnosis means patients can get the treatment they need. In some cases, they can undergo surgical interventions in utero to correct a defect or help the heart grow better before birth. There are many fetal anomalies where an early detection completely changes the course of the delivery. These can include: genetic testing, more ultrasounds, specialty nursing care, social work, fetal surgery, or moving closer to a specialty hospital or clinic to deliver.
It’s also so important for a baby to be delivered at a specialty care center and have the right staff available. Some of these babies are taken to surgery right away or are put on medications and taken to the neonatal intensive care unit. If a baby is born at a small hospital or there’s no knowledge of the defect, it can be the difference between life and death.
How much has ultrasound changed?
It’s changed a lot. When I started, we really didn’t do any vascular scanning. It wasn’t until I was finishing my training, and a doctor asked me to go scan an adult liver using vascular ultrasound (I had no training because it was new), and I thought, “Sure, why not?” (laughs) So we learned as we went. I don’t really feel like the kids that are getting out now are any smarter than someone who’s been doing this for a long time has the experience and has seen everything. You know when something just feels “off.”
And ultrasound itself has progressed. When I started, we used to look at the back of the head for several structures but not the posterior fossa. For spinal defects, we looked at the spine. But I worked at a high-risk clinic in Seattle, and I remember calling my class friend and saying “We’ve got to be looking at the back of the head, because if the posterior fossa is abnormal, it means the spine is abnormal!” And we didn’t have the internet yet, so I sent her pictures in the mail and we incorporated everything new that we learned as ultrasound progressed.
Are the pictures better today?
Definitely, you can see a lot more. We look at the lens of the eye now, we’re trying to get better with the palate, we can see the lip pretty well. But in all honesty, I once missed a cleft lip and we went back and looked at my pictures and they looked totally normal. I asked the doctor how that was possible, and he explained that sometimes if there’s a cleft, the skin can fill the spot and it wouldn’t have been visible on ultrasound. So in the end, ultrasound “describes” it doesn’t “diagnose,” and it’s not perfect.
Four-chamber view of HLHS at 30 weeks gestation in 2D (A) and color Doppler (B) imaging. In this case, the diminutive left atrium (LA) and left ventricle (LV) with wall hypertrophy are seen (A) and in color Doppler some blood filling of the LV is recognized in diastole (B). RV, right ventricle; RA, right atrium. https://obgynkey.com/hypoplastic-left-heart-syndrome-and-critical-aortic-stenosis/
Check back later this week for the concluding Part II!