Does a six-week-old embryo have a heartbeat? The answer is undeniably ‘Yes.’
Does a six-week-old embryo have a heartbeat? The answer is undeniably ‘Yes.’
A fter the Dobbs decision by the Supreme Court this summer that reversed the abortion rights that had been declared in the Roe v. Wade decision, the country has begun to see new disputes over trying to define the new political environment of abortion in the United States. For the past 50 years, these issues have largely been taken out of the hands of the voters and legislatures; instead, they’ve resided with the courts. With Dobbs, those issues have come to the forefront again in our political dialogue.
This is the first election cycle in which this debate has truly been aired, and there have been obvious repercussions. Democrat Stacey Abrams is currently in the middle of a competitive gubernatorial campaign in Georgia. Among the most important issues on her campaign trail has been what she terms “reproductive rights.” In a discussion session last week, Abrams had a profound statement on the subject of fetal heartbeats:
There is no such thing as a heartbeat at six weeks. It is a manufactured sound designed to convince people that men have the right to take control of a woman’s body.
This has been a common retort from liberals for years, in response to various so-called heartbeat bills that have been passed across the country by Republican legislators. In the era of Roe v. Wade, they were mostly theoretical. In the new post-Dobbs era, these definitions and laws are the new legal standard for when women have the right to opt for an abortion, and these conversations carry a much greater weight.
Some of the arguments have reverted to semantics, especially over the basic question “What is a heartbeat?” The term “heartbeat” itself is an anachronism, hearkening back to a time before advanced medical devices. Before stethoscopes, doctors listened to the sounds of the body in the most basic way possible: They literally placed an ear on the patient’s chest. What they heard, the classic sound we refer to, was called a heartbeat. The Oxford dictionary defines it as “the movement or sound of the heart as it sends blood around the body.” As medical advances continued, first with the use of stethoscopes and later ultrasound and other devices, physicians were better able to detect these various “beat” sounds.
But in a general sense, any sound made by the heart chamber’s contraction, and the subsequent flow of blood through the arteries, is generally considered a heartbeat, in layman’s terms. The term is a catchall phrase that has never been clearly specified or defined scientifically.
The semantic arguments were at least honest disagreements about what constituted a “beat.” However, the larger scope of the dispute has been far more dishonest. First and foremost is the question of whether the “heartbeat” matters at all. Why do pro-choice advocate cares whether there is a heartbeat at all? The term is moot for most pro-abortion politicians. But the mendacity doesn’t end there.
A common argument, one that has been perpetrated by numerous media outlets including National Public Radio and the Atlantic, has been the idea that six-week-old embryos simply cannot have a heartbeat, because they don’t truly have a fully developed human heart. This misinformation was even spread by mainstream outlets, most prominently by Glenn Kessler, the lead fact-checker at the Washington Post. The only problem is that the source material used by Kessler was demonstrably in error about the basic science:
“When I use a stethoscope to listen to an [adult] patient’s heart, the sound that I’m hearing is caused by the opening and closing of the cardiac valves,” says Dr. Nisha Verma, an OB-GYN who specializes in abortion care and works at the American College of Obstetricians and Gynecologists. The sound generated by an ultrasound in very early pregnancy is quite different, she says.
“At six weeks of gestation, those valves don’t exist,” she explains. “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.”
That’s why “the term ‘fetal heartbeat’ is pretty misleading,” says Dr. Jennifer Kerns, an OB-GYN and associate professor at the University of California, San Francisco.
“What we’re really detecting is a grouping of cells that are initiating some electrical activity,” she explains. “In no way is this detecting a functional cardiovascular system or a functional heart.”
Everything in these quotes is not only false, but extremely misleading, even though obstetric experts are making the claims. Numerous imaging experts who better understand how ultrasound technology works tried to correct these scientific errors after the article was published, but it has never been corrected or retracted.
The facts are readily available and easy to come by. First, as we have shown above, the definition of a “heartbeat” does not specify anything about the opening or closing of heart valves, nor does it necessarily require the existence of valves at all. The compression of the heart, along with flow of blood, has generally been considered a heartbeat, even before scientists understood the physical structure of the heart. A subtly different argument can be made about the sounds that one can hear during auscultation with a stethoscope or other assisting device because they can define the physical structure making the sound (which is generally related to valves opening or closing). But that is not at all what is being discussed here when we are generally discussing “heartbeats.”
The second issue is treated even more mendaciously. These specific articles cited by Abrams and Kessler clearly were cherry-picked to reach a predetermined conclusion. For example, no ultrasound expert would ever argue that ultrasound detects electrical activity. This is scientific nonsense. However, these articles found so-called experts who said so, defying all scientific logic and common sense.
The physics of ultrasound are quite well defined, as my primer on the science of the subject on Twitter documented. I will briefly review the science and technology here.
Ultrasound probes, called transducers, produce sound waves that have frequencies above the threshold of human hearing (above 20 kHz). Functional ultrasound combines information such as the movement and velocity of tissue or blood, softness or hardness of tissue, and other physical characteristics. In most cases, the active elements in ultrasound transducers are made of special ceramic crystal materials called piezoelectrics. These materials are able to produce sound waves when an electric field is applied to them, but they can also work in reverse, producing an electric field when a sound wave hits them. (This is within the transducer of the ultrasound machine and not within the human body, lest anyone be confused on the matter.) Using the speed of sound and the time of each echo’s return, the scanner calculates the distance from the transducer to the tissue boundary. These distances are then used to generate two-dimensional images of tissues and organs.
A couple of things to note about the hard science of ultrasound. First, ultrasound uses sound waves only to obtain information, which is then translated by computers to create an image. Using sound waves means that ultrasound has no ability, none whatsoever, to detect electrical impulses. It can detect changes in density and motion, but nothing about electricity per se.
The experts above make another claim that is more grounded in fact, however. They argue that the heart of a six-week-old embryo is not fully developed. And in this case, they are 100 percent right.
The embryology describing cardiac development is quite complex, and I won’t go into it in detail here (though this link is useful if you are interested). What we do see is that the six-week-old embryo has a cardiac system that is far more than “a grouping of cells that are initiating some electrical activity,” as stated by the NPR expert. At three weeks, we see the tissue that predates the heart as simple tubular structures. However, by the 40-day mark (less than six weeks old), the embryo has four incompletely formed cardiac chambers. These chambers are not separated by valves as the adult heart is, however. Furthermore, all the chambers do contract in a living embryo at this point (which is the motion that is actually detected and visualized by ultrasound), and the contractions are pushing fluid through the early fetal vascular system.
So, although the embryological and fetal heartbeats are not identical to the adult heartbeat (something that no expert has suggested, as far as I know), it is simply false to say there is no physical contraction of the fetal heart and that those “beats” aren’t pushing fluids through a circulatory system. If that is not a heartbeat, then what is?
There are reasonable and thoroughly sound arguments against the various “heartbeat” bills that have been passed into law around the country. As discussed above, the term “heartbeat” is a scientifically vague term that is more appropriate for laymen’s discussion than legal or medical boundaries. But that is a far different argument from claiming that fetal heartbeats don’t exist, when it is clear by the broad definition of the term that they certainly do. The use of “heartbeats” as a demarcation of when an abortion can or cannot be performed is a highly questionable variable, one that I personally think is wrong, based on both science and logic. But ignoring the basic science behind the idea does us all a disservice, and such misinformation should be corrected.
Furthermore, many progressive groups have themselves long used the term “heartbeat” in defense of abortion rights. Planned Parenthood’s own website stated this until hours after Abrams’s comment, as reported by Jeryl Bier on Twitter. This was followed by media reports confirming the changes:
Planned Parenthood changed its website without any acknowledgment of modifications to say that under the five- to six-week mark of pregnancy, “a part of the embryo starts to show cardiac activity. It sounds like a heartbeat on an ultrasound, but it’s not a fully-formed heart — it’s the earliest stage of the heart developing.” The same webpage previously said that “a very basic beating heart and circulatory system develop,” per an archive of the page from July.
To be clear, nothing about the science has changed; only the politics have. Like those articles above that dismiss the easily provable existence of fetal cardiac activity, most of these arguments are focused not on the science but on how the science will be perceived. They are altering their definitions and claims based on the political result they wish to accomplish. Such misinformation undermines the public’s faith in science as an objective study of the world around us.
Compounding this is the fact that reporters, including so-called fact-checkers, are purposefully ignoring easily demonstrable scientific fact to produce the results that they wish. There is absolutely no excuse for any reporter to ever publish any statement that ultrasound exams show electrical activity. This isn’t even a mistake; it is a failure so large that it undermines the entire credibility of a journalistic institution. A journalistic outlet that doesn’t have a reporter or editors who can challenge such a lie is one that should never be considered credible on any scientific question of the day.
After the Covid-19 pandemic, when we learned how destructive scientific misinformation and government deception can be, it is quite clear that many of us have learned all the wrong lessons. Science must be objective, based on hard evidence, and reported even when the facts presented are terribly inconvenient. If it’s not, we are simply playing politics with people’s lives.
As for the Stacey Abrams statement, it raises a very simple question: Does a six-week-old embryo have a heartbeat? The answer is undeniably yes. The embryo doesn’t have the same heart as an adult, but it has a functioning cardiac structure with four chambers; it lacks valves but contracts and propels fluid through its circulatory system. If that is not a heartbeat by any rational definition known to man, then I don’t know what is.