The new Texas law bans abortions after a "fetal heartbeat" is detected, usually about six weeks into pregnancy. But doctors say that's not an actual medical term and it's being used inaccurately.

Transcript

MARY LOUISE KELLY, HOST:

The Texas abortion law that has just gone into effect says that, quote, "a physician may not knowingly perform or induce an abortion on a pregnant woman if the physician detected a fetal heartbeat for the unborn child," unquote. So what is a fetal heartbeat? NPR's Selena Simmons-Duffin reports it is not as simple as it may sound.

SELENA SIMMONS-DUFFIN, BYLINE: When a doctor holds a stethoscope up to someone's chest, it sounds like this.

(SOUNDBITE OF HEART BEATING)

SIMMONS-DUFFIN: What is making that sound?

NISHA VERMA: The opening and closing of the cardiac valve.

SIMMONS-DUFFIN: That is Dr. Nisha Verma of the American College of Obstetricians and Gynecologists. And she says the sound that you would hear with an ultrasound in very early pregnancy is different.

VERMA: At six weeks of gestation, those valves don't exist. And so the flickering that we're seeing on the ultrasound that early in the development of the pregnancy is actually electrical activity. And the sound that you hear is actually manufactured by the ultrasound machine.

SIMMONS-DUFFIN: Dr. Jennifer Kerns is an OBGYN and an associate professor at the University of California San Francisco.

JENNIFER KERNS: In no way is this detecting a functional cardiovascular system or a functional heart. And so the term fetal heartbeat is pretty misleading when we're talking about what is detected early in pregnancy.

SIMMONS-DUFFIN: Kerns says fetal heartbeat might be used in conversations with patients, but it's not actually a clinical term.

KERNS: This is a term that is not widely used in medicine. I think this is an example of where we are sometimes trying to translate medical lingo in a way that patients can understand. And this is a really unfortunate side effect of this type of translation.

SIMMONS-DUFFIN: The term fetal heartbeat has been used in laws related to abortion for a while now. It's not new. And in practice, it would be really hard for a woman to know she's pregnant before this sound would be detectable by an ultrasound. She would have to be tracking her periods carefully, have regular periods, notice she's late and then quickly get in an appointment. Kerns says the point of using fetal heartbeat in the Texas law is clear.

KERNS: It's clearly trying to move the needle back to almost the point of detection of pregnancy with the goal of outlawing nearly all abortions.

SIMMONS-DUFFIN: Selena Simmons-Duffin, NPR News. Transcript provided by NPR, Copyright NPR.

Tags: fetal heartbeat abortion ban  pregnancy  Texas  Women's Health  abortion  Policy-ish