There’s a scene on the CBS show Criminal Minds in which JJ, a pregnant FBI profiler, halts a conversation about a killer to put headphones over her pregnant belly. She tells the others she doesn’t want her child to hear the gory details of the conversation, as if talk of dismembered women will permanently scar the developing fetus still inside of her. The rest of the team of analytical thinkers readily assent to JJ; no questions are asked.


When I watched this scene, I was folding onesies for my own child, who right then, was wiggling inside my womb, making me constipated and nauseous. When my mom called a few minutes later, she balked when I told her which show I was watching. “What about the baby?” she said.

The barrier between mother and child is literally permeable and philosophically up for debate. A defining factor of pregnancy is the list of things you’re forbidden from putting in your body, as not to harm your fetus: alcohol, drugs, medication, lunch meat, anything otherwise impure. You are asked, even, to refrain from allowing certain things to enter your mind: studies on pregnant woman show links between increases in maternal stress and fetal stress, and maternal stress has even been linked to preterm birth and schizophrenia.


Those cause-and-effect links are proven and tangible—while other links between mother and baby slip into a nearly spiritual realm. Long after a child has left its mother, its fetal cells remain lodged inside the mother, crossing the placenta and becoming part of the bloodstream. Mothers, too, leave their cells in their children: these cells cross the placenta in the opposite direction, strengthening the immune system and, well—no one is quite sure what else.

The science leads easily to superstition. Today, a thriving contemporary market of goods exists to promote fetal positivity and protect your baby from the wicked influences of the world. Bellybuds, the $49.99 sound system for your baby, advertises its ability to make a positive maternal impression: to transmit sound into the womb, so parents can “deliver audio stimulation to their developing child to start creating those memories now.” Bellypod, a tampon-like speaker that can be inserted in the vagina, takes that idea even further.

The logic is ancient. Upset the mother and ruin the baby; if the mother is sweet, the child will be sweet too. Expectant mothers are responsible for a double version of the traditional idea of the woman’s body, generally thought to be either pure or defiled. It’s a logic rooted in biological fact—the state of a pregnant woman’s body does affect her fetus—that has been twisted into an equally powerful psychological fiction, which extends to a woman’s mind. The idea that what a pregnant woman sees and thinks about will manifest in her unborn child dates back centuries, and still persists today.

In 1897, CJ Bayer wrote a pleading appeal to pregnant women in his book Maternal Impressions:

“The basic principle which we wish to impress upon the reader is: That a mother who is in the condition to which attention is called, who has an imperfectly formed object, such as a monstrosity of any kind in her mind, and who dwells upon it, or who has impure or vulgar thoughts and mean or unholy ideas, or who has murder in mind—that is, would like to kill her unborn babe—will impress such a formation of the brain structure of her offspring, as will form its desires in the direction which her thoughts have taken.”


But the underlying theory can be found as far back as the Bible, when Jacob makes a deal with his father-in-law Laban to only take the spotted or striped goats in the flock as his dowry payment for Rachel and Leah. Jacob vows to Laban that if an all-white goat is found among his flock, it will be considered stolen.

So, in order to ensure his flock remained spotted, Jacob has branches cut and the bark peeled from them in strips so that the inner wood showed. He makes his flocks cross over these striped branches on their way to eat and drink. He makes the strong ones mate in front of the branches, so they would be dark and spotted. The weak ones he sets apart from the branches, so they would be born white and sent back to Laban.


The author of Genesis wrote: “In this way the man grew exceedingly prosperous and came to own large flocks, and maidservants and menservants, and camels and donkeys.” In other words, early Biblical commentators believed that just the vivid sight of the striped branches was enough to imprint on the goats in the womb.

Hippocrates explained a similar theory in the 4th century BC: “If a pregnant woman feels the desire to eat earth or charcoal and then eats them, the child will show signs of these things.” Pliny the Elder argued years later—between 77 and 79 AD—that the reason for greater variability among human appearance over animals is because humans possess a greater capacity for imagination. Aristotle, in his humbly titled Masterpiece, wrote that an adulteress having sex with her lover can conceive of a child who looks like her husband, by simply imagining his face during conception. He added, “And through this power of imaginative faculty it was that a woman, at the time of conception, beholding the picture of a black-a-moor, conceived and brought forth a child, resembling an Ethiopian.”


Many early stories about maternal impressions concerns taboos around race. There is a recurring legend of dubious historical documentation that tells of Hippocrates saving a princess accused of adultery because she had given birth to a black child. His defense was recounted by sixteenth-century surgeon Ambroise Pare in his own book On Monsters and Marvels:

“Her husband and she both having white skin...the woman was absolved upon Hippocrates persuasion that [her child] was [caused by] the portrait of a Moor, similar to the child, which was customarily attached to her bed.”


Other suggestions of perceived sexual deviance creep into these stories, too. In A Cabinet of Medical Curiosities Jon Bondeson tells the story of a noblewoman in Ursini who was born with the fur and paws of a bear. It was the thirteenth century, and the defect was blamed on a picture of a bear that hung in the woman’s bedchamber. “The things desired by the mother are often found impressed on the child that the which the mother carries at the time of the desire,” Leonardo Da Vinci once famously wrote in his Quaderni d’Anatomia, which he compiled between 1485 and 1515.

The same theory was also put forth in the Vedas, a collection of texts that originated in ancient India. Naomi Wolf recounts in Misconceptions: Truth, Lies and the Unexpected Journey to Motherhood that many Southeast Asian communities practice “sympathetic magic.” She explains: “If a pregnant woman mocks someone with a deformity, her child will be born with the same condition; if she eats dark fruit, her baby will have a mottled complexion; if she sees quarrels, her child will have a difficult temperament.” And so on.


Centuries later, at the dawn of the scientific age, C.J. Bayer’s book told the same horror stories. There is a pregnant woman who watches a firework explode into a child’s head; she then gives birth to her own baby with a large indent in its head. If only she would have wished and prayed that her child would have no deformities because of witnessing that event, Bayer laments. He tells stories of mothers craving beef during pregnancy, whose infants could only being soothed by suckling on sticks of beef, and of a Jewish mother who craves pork, and whose child cries inconsolably until he is offered some bacon.

A 1919 public health education poster scoffs at the idea of maternal impression, but then advises women that they should still be emotionally on guard for their baby’s safety: “Worry, fear and anger may affect his mothers’ blood, which supplies his food. Therefore, she should be calm, happy and sweet-tempered.”


“Be sweet!” is still the dominant advice for pregnant women today. Take a rest. Sit down. Don’t worry your pregnant mind. Think of the baby. And pregnant women who expose themselves to that which is not sweet—who have a sip of wine, take some cold medicine or regularly watch gory crime procedurals before bed—they are selfish. They are unable to take heed of maternal impressions and put their child’s needs before their own.

Science has always believed that women’s bodies are permeable vessels: weak clay to the man’s molded steel. For pregnant women, this is even more so. There is a bias at play even when the facts are unknown or neutral: in a recent interview with NPR, Janet Williams, a professor of pediatrics at the University of Texas Health Science Center in San Antonio, advised women that there are too many unknowns with drinking while pregnant, so women should just avoid it all together, which is both an understandable suggestion and yet completely regressive. If a pregnant women were to avoid all unknowns, they would be locked in quiet closets listening only to Mozart—and mom blogs would still debate how harmful the light is coming in from under the door.


For science, mystery is a thing to be conquered. And if there’s any mystery greater than a women’s body, it’s that woman’s body when she’s carrying a child. The history of medicine is one of isolating women—strapping them down, tying them up, locking them away. But to immediately cloister a woman from the world around her, not only to protect her but to protect her children, is to assume that her body contains mostly weaknesses. The mother-child connection in pregnancy is fundamentally opaque; the nature of creation is fluid and flexible, and in talking about what’s passed on from mother to fetus, we rarely talk outside terms of purity. We rarely talk about strength.

There is undeniably an almost mystic connection between mother and child, one that holds fast even into adulthood. The subcortical regions of our brains are deeply influenced by this first love, this longest lasting connection. But the extent of this connection remains unknown. No one can say if the fact that I watched crime shows will give my children some unknown deviance, or if that allergy medicine taken out of desperation in the second trimester will be the reason my daughter doesn’t make it into Yale. We only know there’s such a thing as a maternal impression. I hope for a future in which that idea makes us something other than afraid.


Lyz Lenz has written for The Hairpin, The Toast, The New York Time Motherlode, and other various and sundry internet entities. Find her on twitter @lyzl.

Illustration by Tara Jacoby