New 3-D Ultrasound: Changing Views of the Unborn

TACOMA, Wash. — A whole new “window into the womb” that confirms the psalmist's words, “I am fearfully, wonderfully made” is said to be emerging with the development of three-dimensional ultrasound technology.

Although it is at least several years away from everyday use, 3-D ultrasound “really brings to mind what Psalm 139 says,” said Dr. Byron Calhoun of Tacoma, Wash., president of the American Association of Pro-Life Obstetricians and Gynecologists, a special-interest group of the American College of Obstetricians and Gynecologists.

Calhoun, who has used the technology on an investigational basis, expects that 3-D ultrasound will be especially helpful in diagnosing fetal abnormalities in the first trimester, when a “little person” with head, eyes, hands, and fingers is visible. Among the deformities experts say can be seen with 3-D ultrasound are spina bifida and cleft lip and palate. Researchers also have said a 3-D image can help parents bond with their unborn child and discourage smoking and alcohol consumption on the part of the mother.

“It's a different world for us to be able to look at,” Calhoun said. “The first-trimester stuff we're seeing is pretty impressive. When you pull [the image] out, it looks like a baby. Realistically, that's going to be a powerful tool.”

Pro-life advocates hope the technology will bolster the view that life begins at conception and is deserving of protection.

Thomas Glessner's organization, the National Institute of Family and Life Advocates, helps pro-life pregnancy centers acquire and use two-dimensional ultrasound equipment. He can't wait to get his hands on the 3-D equipment. “When the public understands and sees” 3-D, he said, “it will be nothing but a benefit for what we've been saying all along.”

Although Calhoun agreed it is too early for pregnancy centers to begin using 3-D equipment, which costs upwards of $100,000 and requires a sophisticated skill level on the part of technicians, he said the images the technology provides are indeed compelling.

“It's hard to look at this little person with a heartbeat and call it a blob of tissue. It does not look like a tad-pole or a blob of tissue. It's a little person, stretching, tumbling, acting like a kid … The heart is beating and it's really hard for an abortionist to get through it. They hate ultrasound.”

Representatives of the National Abortion Rights Action League were asked to comment about the impact of 3-D ultrasound on their movement, but declined to do so.

Three-dimensional ultrasound, also known as volumic sonography, uses special probes that automatically scan an area of the body, producing a series of planes that form a pyramid. The actual scan only takes 3 to 10 seconds, but the technology for achieving a three-dimensional image in so-called real time is still not available. Now, the data from the scan must be loaded into a computer and processed before an image can be generated.

Because 3-D ultrasound uses voxels (volumes) instead of pixels (dots) as in two-dimensional pictures, the images it produces take a lot of time to process, Calhoun said. To locate something freely in space and reconstruct it involves a complicated mathematical formula that today's processors are not fast enough to handle in real time.

However, Edith Stone, director of sales and marketing for Shimadzu Ultrasound-North America, Torrence, Calif., said as processing power gets more extensive and less expensive, 3-D ultrasound will become more user-friendly.

“The key to 3-D is computer power. … What is to everyone's advantage is that the cost of faster computer components is decreasing. The future may be just a year or two years out.”

Stone said images of fetal faces constitute much of what is emerging from 3-D ultrasound now. “What we have to be able to do to make 3-D valuable is what we call cut plane. Yes, there will be a rendering of the fetal face, but then you'll take away parts of the anatomy and look at other parts.

As an example, we would take away part of the fetal head and look at the brain, and be able to make an actual quantitative analysis.”

An advantage of 3-D ultrasound over 2-D, which was developed in the 1950s, is that it produces higher-resolution images that are more accurate. The limitations of 3-D are that the operator and patient must remain immobile for the duration of the scan, and that storage of the images requires a large computer memory. Additionally, the entire fetal body cannot fit into the image, except during the first two months.

The advent of 3-D ultrasound raises questions about what the new technology will contribute to the field of obstetrics, said Stone. For instance, she said, an infant with a cleft palate would likely have such a problem corrected after delivery anyway.

The new technology also will be helpful to gynecologists because of its effectiveness in visualizing cysts and ovaries more accurately, Calhoun said. Other long-term, major uses of 3-D ultrasound likely will involve cardiac and abdominal imaging, Stone added.

Calhoun said he is optimistic about the technology's impact on changing attitudes toward abortion.

“For virtually every woman who is shown the heartbeat and the beautiful features of her child — that's her baby. It makes it very difficult for them to do the abortion.”