Theresa Brown is a hospice nurse and author of "The Shift: One Nurse, Twelve Hours, Four Patients' Lives." The views expressed here are hers. Read more opinion on CNN.

(CNN) President Trump recently said that babies who survive so-called late-term abortions sometimes die afterward as a result of bedside executions. This lie is so outrageous and horrific that the only good response to it is to state that such things never happen. Because they don't. Physicians practicing in the United States do not kill babies. The politics of why our President would make this claim seem obvious. Because I'm a nurse, I want to explore all the misapprehensions -- of biology, psychology, and ethics -- that this statement leans on and unfairly exploits.

Theresa Brown

First, though, some facts: According to the CDC, 1.3% of abortions occur on or after 21 weeks of pregnancy. In 2015, the year for which the most current statistics are available, that means approximately 8,000 pregnancies were ended in the third trimester of pregnancy. If that seems like a high number, consider that a recent study from Harvard Medical School found that roughly 45,000 Americans die each year from lack of health insurance, and our President is not calling insurance company CEOs de facto executioners (for the record, neither am I).

Contrasting adults who die for lack of health insurance and fetuses who are aborted is not accidental but gets at the core of the biological misunderstandings that underpin the anti-abortion movement. The "unborn child" does not exist as a unique biological entity, but depends on a symbiotic relationship with the mother, a symbiotic relationship that ends only when the umbilical cord is cut following birth. Fetuses are physiologically not people—they cannot live independent of their mothers.

Trump's choice of the word "execution" was not accidental. He was specifically attacking Wisconsin Gov. Tony Evers, a Democrat, but also upping the emotional ante in discussions of abortion by implying that abortion is not only murder -- a common refrain of those opposed to abortion -- but more specifically, murder meant as punishment. He may also have been embellishing on what used to be called "partial-birth abortion," or intact dilation and extraction, but "partial-birth" abortions have been illegal in the United States since 2003 , so even obliquely recalling it is a canard used for political gain.

Pregnant women have abortions because, for whatever reason, they believe they cannot raise the child they are carrying in the way they would most like, the child that is, quite literally, made of the substance of their own body and cannot live without them. A mother myself, I believe that only a pregnant woman can determine whether continuing or ending her own pregnancy is the correct ethical choice.

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