Rethinking Fetal Heart Screening in Pregnancies With Diabetes

Pregnancy can come with many extra layers of care, especially for patients with pregestational diabetes—meaning diabetes that existed before pregnancy began. One of the biggest concerns in these pregnancies is the increased risk of congenital heart disease (CHD), or heart problems a baby is born with. Because of this risk, many guidelines recommend that all of these pregnancies include a fetal echocardiogram, a specialized ultrasound focused only on the baby’s heart.

But is that always necessary?

A new study suggests that in some settings, there may be another way.

Researchers looked at how a selective referral program worked for pregnant patients with type 1 or type 2 diabetes at a large, experienced medical center. Instead of automatically sending every patient for a fetal echocardiogram, the team used detailed anatomy ultrasounds first. These routine scans included expanded views of the baby’s heart and were performed by highly trained ultrasound professionals. If something looked unusual, or if the images weren’t clear enough, the patient would then be referred for the more specialized heart exam.

The goal was simple: find out whether this approach could still catch serious heart problems before birth.

The findings were encouraging.

The study showed that all of the major heart conditions in the babies were identified before delivery, even though only a portion of patients went on to receive a fetal echocardiogram. This suggests that when detailed anatomy scans are performed carefully and by experienced teams, they may be enough to spot the most serious concerns.

Some smaller or less serious heart differences were not found until after birth. However, these were minor issues that did not require urgent treatment and are often difficult to detect before delivery.

This distinction matters.

Not every heart difference has the same impact. Some conditions need immediate care after birth, while others may simply need monitoring over time. The study’s selective approach focused on making sure the most urgent and life-changing conditions were found early.

Why is this important?

Fetal echocardiograms are valuable, but they also require specialized equipment, trained staff, and time. In many healthcare systems, these resources are limited. Reducing unnecessary referrals could help shorten wait times and improve access for patients who need these exams most.

It may also help reduce stress for expectant parents. Being referred for additional testing can create anxiety, even when everything turns out normal. A strong initial screening process may help avoid some of that uncertainty.

The study also highlights the importance of ultrasound quality. The success of this selective system depended on advanced imaging techniques and experienced sonographers and physicians. That means this approach may not work the same way in every clinic or hospital. Centers with fewer resources or less specialized training may still benefit from universal fetal echocardiograms for these higher-risk pregnancies.

For now, this research adds to a growing conversation in maternal-fetal care: how can healthcare teams provide the best care while also using resources wisely?

The answer may not be one-size-fits-all. But studies like this show that with the right expertise and technology, more personalized approaches to prenatal care may be possible.

Want to learn more? Read the full study in the American Institute of Ultrasound in Medicine’s (AIUM’s) Journal of Ultrasound in Medicine here https://onlinelibrary.wiley.com/doi/10.1002/jum.70324

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AIUM members always have full access to the journal; not a member? Join here.

Cynthia Owens, BA, is the Publications Coordinator for the American Institute of Ultrasound in Medicine (AIUM).

Ultrasound Imaging of Obese Pregnant Women

As the rate of obesity continues to increase worldwide (last reported by the CDC as 42.4% as of 2017–2018), it has become even more evident that there is a great need to improve fetal cardiac visualization in obese pregnant women. Less than 50% of morbidly obese women have successful fetal 4-chamber and outflow tract visualization, compared to almost 90% of nonobese women.

Obese women are also significantly more likely than normal-weight women to have children with a congenital heart disease, with an even higher risk in morbidly obese women, who give birth to children who have higher odds of having atrial septal defects, hypoplastic left heart syndrome, aortic stenosis, pulmonic stenosis, and tetralogy of Fallot.

And when obese pregnant women have reduced rates of complete anatomic surveys, lower detection rates, and increased risk of fetal anomalies due to less than perfect anatomy visualization, how do we improve the fetal cardiac visualization?

A team of researchers from Eastern Virginia Medical School looked into whether ultrasound (US) imaging in early gestation could help.

Amara Majeed, MD; Alfred Abuhamad, MD; Letty Romary, MD; and Elena Sinkovskaya, MD, PhD, performed a study in which all study participants (obese pregnant women) with a gestational age of 13 weeks to 15 weeks 6 days, underwent an US exam using a transvaginal or transabdominal approach and color Doppler US for fetal cardiac screening, which they defined as complete when all components of the 4-chamber, right ventricular outflow tract, left ventricular outflow tract, and 3-vessel views were clearly visualized. The participants also underwent a traditional transabdominal examination at 20 to 22 weeks, and if that exam was incomplete, underwent another 2 to 4 weeks later.

What they found was that the addition of early-gestation US to the 20- to 22-week US exam of obese pregnant women substantially improved the visualization of fetal cardiac anatomy. And for the women with a BMI of greater than 40 kg/m2, the cardiac screening completion rate was even higher (significantly so) for the early-gestation exam plus a traditional exam (90%) than for the traditional exam plus the second traditional exam (72.7%).

Adding an ultrasound exam at a gestation age of 13 weeks to 15 weeks 6 days substantially improved the visualization of fetal cardiac anatomy, particularly for the women with a BMI of greater than 40 kg/m2. Having complete or more complete anatomy screening can enable an earlier, accurate diagnosis.

To read more about this study, download the Journal of Ultrasound in Medicine article, “Can Ultrasound in Early Gestation Improve Visualization of Fetal Cardiac Structures in Obese Pregnant Women?”. Members of the American Institute of Ultrasound in Medicine can access it for free. Join today!

If you have any questions about the study, please ask in the comments; the authors of the article will be happy to respond.