Three questions pregnant women should ask about fetal ultrasounds
For pregnant women, a general fetal ultrasound between 18 to 22 weeks of pregnancy is standard medical practice. Ultrasound scans, which use high-frequency sound waves to show images of the fetus, placenta and amniotic fluid, help doctors to see how the baby is developing and to detect possible birth defects.
While ultrasounds can help identify heart defects—the most common type of birth defect—the imaging technique often can miss detecting such abnormalities. In fact, most cases of major heart defects are still being missed by fetal ultrasounds, including in the United States.
“Heart defects affect about one out of 100 babies,” says Dr. Mark Sklansky, professor and chief of the division of pediatric cardiology at the David Geffen School of Medicine at UCLA. “It’s clear that babies with major heart defects can do much better when diagnosed before birth. The problem is that it can be difficult to find a heart defect during a prenatal ultrasound because the baby’s heart is very tiny—smaller than the size of walnut—and it beats very fast. Also, the baby’s position and the mother’s tissues can make it very challenging to see the heart well.”
Moreover, different doctors and different practices do not necessarily perform ultrasounds the same way, Sklansky says.
To help women get an optimal ultrasound of the baby’s heart, one likely to be able to detect a heart defect, if present, Sklansky recommends they seek a provider that offers advanced technology and a thorough screening of the heart. He suggests that patients ask the following questions:
1. Are the ultrasound images of the heart stored as still-frame pictures or as video clips? Video clips have been shown to help improve detection of heart defects that might be missed if only still-frame images are stored.
2. Does the fetal ultrasound include the use of color Doppler to see blood flow inside the heart? The addition of color Doppler has been shown to increase detection of heart defects.
3. In addition to looking at the four chambers and the outflow tracks of the right and left sides of the heart, will the ultrasound provide a so-called three-vessel view? This additional screening view has also been shown to improve the detection of heart defects.
Sklansky says some of these features may exceed the practice standards set by organizations such as the American Institute of Ultrasound and Medicine and the International Society of Ultrasound in Obstetrics and Gynecology, but should still be covered by insurance that covers the basic mid-gestation fetal ultrasound.
The good news is that if a defect is found early, the patient’s doctors can monitor the pregnancy more closely and consider additional testing for other abnormalities. If abnormalities are found, the doctors can plan ahead for any procedures that may be necessary soon after delivery to protect the newborn’s health.