The On-line Journal of Mary Esther Malloy

Protecting Babies from Toxic Stress

Liz looked down at her phone and got a shock. In labor…come to hospital, the message read. My best friend was in the process of adopting a baby via an open adoption, but the baby wasn’t due for another two-and-a-half months.

Liz wasn’t entirely surprised the baby was coming early. Stress during pregnancy is a predictor of preterm labor and Mia, the birth mother, had it in buckets.

In her mid-30s and living in rural Pennsylvania, Mia and her husband were raising their family on low-wage jobs. Mia was working at McDonald’s when she found out she was pregnant with her sixth child, due a year after her fifth. Her husband was accusing her of infidelity and they fought continuously. Sometimes the police were involved. With the stress, Mia wasn’t eating well and said she couldn’t give up her pack-of-cigarettes-a-day habit. Mia felt pushed beyond what she could handle and made the tough decision that adoption was the answer for her family.

Liz quickly packed a bag. The baby was only 30 weeks. His prematurity alone would put him at risk for learning delays and health challenges. And then there was the baby’s stress to consider: the stress of life in the NICU, the strain of being separated from his birth mother, following significant levels of stress in utero.

Stress this early in a person’s life is often dismissed as inconsequential: He’s only a baby; at least he won’t remember. But research is showing that too much stress too soon can alter how genes function and point a person toward a lifetime of anxiety and the ravages occasioned by chronically surging stress hormones. Stress in infancy, or prenatally, may be one of the biggest influences on mental health later in life.

The good news for my friend Liz and her baby is that scientists are examining how an intensely responsive approach to caring for a stressed infant can restore a normally functioning stress response. Providing exceptionally patient, persistently attentive care for an agitated baby isn’t easy, especially when parents are struggling to get by. But experts are coming to understand that such care has the potential to reverse epigenetic or “above the genome” changes that may have occurred prenatally or in early infancy.

As Liz high-tailed it to the hospital on a hot summer morning two years ago, the baby was born by emergency cesarean. He was admitted to the NICU weighing just 3-and-a-half pounds, requiring a ventilator and feeding tube. Liz camped out with Mia to assist with her recovery and took over care for the baby, whom she and Mia, independently of each other, named Julian.

Liz was with me for the births of each of my three children. Now it was my turn to help. I filled a large cooler with bottles of human breast milk that had been donated to the newly-opened New York Milk Bank and drove to meet Mia and young Julian.

Doctors assured Liz and Mia that Julian was doing fairly well, so we weren’t overly anxious about his survival. But we had concerns.

Excess stress at any point in the lifespan can damage human health, and none of this could have been good for Mia. But, as experts affirmed in response to the Trump administration separating migrant children from their parents, chronically elevated levels of stress hormones during childhood can be particularly harmful, especially in the absence of supportive adult relationships, where tolerable stress can reach toxic levels.

Not all stress is bad, but repeat early exposure to stress from separation, violence, abuse, neglect, divorce, a parent with an addiction or mental illness, and experiences of racism and poverty can “tip a child’s developmental trajectory,” and change people “in ways that can endure in their bodies for decades,” according to Dr. Nadine Burke Harris, CEO and founder of the Center for Youth Wellness in San Francisco.

Toxic stress during childhood or gestation disrupts the “architecture of the developing brain,” reports the National Scientific Council on the Developing Child. The effects can be long lasting and include an increased risk of illnesses such as heart disease, diabetes or stroke, and mental health challenges including depression and anxiety disorders. Toxic stress also disrupts memory and learning.

And the younger the child, the greater the potential for harm. “We now know that there is no single period as important for life outcomes of developmental health as the period from conception to a child’s first birthday,” writes Daniel Keating, author of Born Anxious, winner of the 2019 Eleanor Maccoby Book Award in Developmental Psychology.

“The evidence is clear,” says Keating, a professor of psychology at the University of Michigan, “exposure to a steady drip of toxic stress before a child turns one can cause a dysregulated stress response, creating havoc in that person’s life and the lives of those around them.”

In an effort to discover why some children struggle with focus and impulse control while others thrive, and what causes some adults to feel frequently anxious and overwhelmed, with hair trigger responses to daily challenges, Keating led an interdisciplinary network of senior research scientists for over a decade with the Canadian Institute for Advanced Research (CIFAR).

Keating’s team had a breakthrough when Michael Meaney from McGill University shared findings from studies on rodents with hyperactive stress responses. Like other researchers, Meaney and colleagues observed a connection between early exposure to stress and later in life attention deficit and hyperactivity disorder-like behavior. Meaney, however, made a major discovery: he identified a way in which early stressful experiences can get lodged in the body.

Meaney examined a gene, NR3C1, that plays a central role in dialing down the stress response. Once a threat has passed, NR3C1 tells the body to turn off the deluge of stress hormones that have activated a “fight or flight” state of hyperarousal. The body then calms down, returning to homeostasis, or “rest and digest.”

Meaney discovered that in young rat pups who were stressed by low levels of maternal nurturing, this gene was “methylated.” In pups who were licked and groomed less than their peers, a chemical compound, methyl, was getting in the way of how NR3C1 functioned. Instead of lowering floodgates to stop the tide of cortisol following a threat, methyl jammed this stress gene, leaving the river to roar unchecked. The result was a near steady oversupply of cortisol, causing the animals to be excitable and high strung as they grew older. The DNA itself was not altered, but how this gene operated was changed epigenetically and early life stress became biologically embedded.

Subsequent research with primates and humans led Keating’s team to conclude that with humans, too, this particular epigenetic modification can happen when a fetus or young child experiences high cortisol surges too frequently. If a woman like Julian’s birth mother, Mia, is chronically stressed while pregnant, then her frequent and high cortisol releases can infiltrate the fetus before birth, triggering epigenetic changes that predispose a child to a hyperactive stress response. Or, says Keating, parents who are extremely anxious can experience difficulty forming a strong attachment with their baby, possibly generating new toxic stress or failing to correct the effects of previous stress.

In Julian’s case, I was worried that the “bell of early life adversity” had been rung, as Keating described it to me, and that un-ringing the bell would prove challenging.

Exercise, meditation, good nutrition and healthy social relationships have all been shown to lower the volume on stress. But Liz and I grappled together with the question of what tools could help a baby like Julian who was clearly at risk for a dysregulated stress response. In our search, we came across “super nurturing,” a term coined by Keating’s team to describe a type of care that has the potential to change the lives of those born anxious.

Meaney’s research revealed another major finding: there was a window of time during which it was possible to actually reverse stress methylation and restore lab rats to a normal stress response. The key was ensuring that pups at risk for a hyperactive stress response received adequate levels of licking and grooming over their first 10 days, a sensitive period roughly equivalent to a human’s first six months.

Similarly, rhesus monkeys born to highly reactive mothers were able to overcome their own hyperreactivity if they were fostered to exceptionally calm, nurturing monkeys, NIH researcher Steve Suomi found. When at-risk infants received extra physical contact and were patiently, even stubbornly held and coddled, even if the infant showed aggression or was unresponsive, the monkeys grew up to have normal stress responses. They also had a greater probability of achieving high social status as adults, possibly because they were highly attuned to social cues but didn’t exhibit the behavioral problems of their peers who did not receive the extra care. “One thing that comes out of these studies,” says Keating, “is the extreme power of social attachment.”

Keating’s CIFAR team came up with the term “super nurturing” to describe the extra attentive care. “If you can get at this early enough, and provide intensely responsive nurturing to babies who are jumpy, hyper and difficult to soothe, there is a much higher prospect of resilience and success later on,” says Keating. And while we have long known that parental attachment is crucial to all babies, this appears to be especially true for those whose stress systems are working overtime. They seem to need more buffers against stress reactivity, especially through their first year.

Liz was sometimes overwhelmed by the challenges that lay ahead, but she was eager to give super nurturing a go. She felt Kangaroo Mother Care was the place to start, an approach to caring for a vulnerable newborn that emphasizes ongoing skin-to-skin contact between a parent and baby.

On my next visit to the hospital, along with groceries for Liz and another cooler of breastmilk, I brought a tie-on wrap used to keep babies skin-to-skin on their mothers’ bodies. This, I hoped, would help Liz keep Julian’s stress in check. A study conducted in a Cape Town hospital found that newborns looked peacefully asleep whether on their mothers’ chests or in nearby cribs—but appearances, in this case, were deceiving. Autonomic nervous activity tripled and deep sleep was 86 percent lower when the infants slept separate from their mothers. The findings underscore concerns about the impact of separating mothers and babies. “We knew that this was stressful,” commented Dr. John Krystal, Chairman of the Department of Psychiatry at Yale, “but the current study suggests that this is a major physiologic stressor for the infant.”

We now understand that babies have a place-dependent competence, says Nils Bergman, a neonatal neuroscience specialist and one of the researchers on this study. “When a baby is born and taken to the incubator, we see chaotic behavior. Cortisol is elevated. There is no sleep cycling. Conversely, when a baby is with his mother, we see a relaxation phase, a crawling phase, a suckling phase. We have organized sleep cycles.” Currently part of a five-nation study examining the impact of on-going skin-to-skin contact, Bergman calls for “zero separation,” saying, maternal infant separation has no scientific foundation. His is a voice in a growing chorus of doctors who no longer forbid mothers and babies contact during sleep and instead teach parents safe ways to offer close, responsive parenting through the night.

With near-constant loving attention and touch, Julian’s brain could brew up a cocktail of neurochemicals including oxytocin that buffer against stress. Often described as the “social connection,” “love” or “trust” hormone, oxytocin sponges up extra cortisol that may be in a baby’s system. High-oxytocin practices such as skin-to-skin contact, breastfeeding and safe co-sleeping help the baby’s body regulate stress, and, as Keating says, “build a physiology inclined toward calm and stability.”

It is not yet a standard of care, but six major international health organizations including the World Health Organization and the American Academy of Pediatrics now recommend the universal use of Kangaroo Mother Care for pre-term and low-weight babies.

The staff in the NICU that housed Julian were supportive of Liz’s efforts. She spent weeks in the NICU holding her son, alternately singing to him and on the phone with adoption lawyers. Their lives weren’t without stress, but they clung to each other.

Once they got home, Julian cried a lot—often inconsolably. I was struck by the high level of muscular tension in his tiny limbs, even when he wasn’t upset.

Liz dialed up the super nurturing on a number of fronts. Her first priority was to offer as much physical closeness as she could reasonably manage to lower Julian’s cortisol levels and elevate oxytocin. Liz bought a skin-to-skin carrier that Julian more or less lived in for his first months. She got an in-bed sleeper and snuggled her son through the night, where he was most peaceful.

Then, there was the demanding work of helping Julian navigate his biggest emotional tsunamis.

Since nothing seemed to quiet Julian once he got on a crying jag, Liz flipped her perspective. Instead of struggling fruitlessly to figure out what was wrong with her hysterical baby, she did her best to help Julian feel cared for and connected through his crying fits. Inspired by the work of Patty Wipfler, founder of Hand in Hand Parenting and co-author of Listen, Liz decided that if she were certain her son’s basic needs had been met, she would simply hold him and listen to his upset without trying to hush him.

Recognizing how difficult this was for her at times, Liz would have a friend over whenever possible to support her while she held Julian for these bouts of crying. One day the crying was a blast of fury that went beyond anything Liz had experienced so far. Finally, her friend had to leave. Liz hung in there for more hours, holding her son and reassuring him that he was safe. At long last, he fell deeply asleep.

After this epic cry, Liz described a distinct shift in Julian. His crying became less frequent and frantic. He had more time quietly attentive to his surroundings. She saw leaps forward in what he could do. The relief and clarity any of us experience after a good cry is probably from the release of adrenocorticotropic hormone in tears, a chemical precursor to cortisol production. I can’t help but think that Julian has thrived at least in part due to his many good cries in Liz’s arms.

At 27 months, Julian is still small, but he is doing so well that he has twice failed to qualify for state support services because he is meeting and even exceeding developmental milestones. Like any two-year-old, Julian has his share of tears and tantrums. Liz continues to do her imperfect best to lovingly support Julian through the choppy waters of toddler upset until the post-storm calm returns him to his relaxed, inquisitive self, capable of moving a little better through his day.

None of this has been easy. Super nurturing baby Julian would have been nearly impossible for Liz, a single mother, to do without her network of friends and family. Liz has had to have more than a few good cries herself through the process. As Liz reflects on her beginning with Julian though, she says the most significant factor in getting off to a solid start was that she was able to afford time off work for much of Julian’s first year.

Most American families, of course, don’t share Liz’s economic advantages. Even with a strong economy, families are under strain. Some 41 percent of U.S. children—almost 30 million—are being raised in poor or low income households, a number that includes more than five million infants and toddlers.

The metaphor Keating uses to describe what is going on in the U.S. is one of a social system set up with a “really steep ladder.” And the steeper the ladder, the greater the risk of losing your grip and sliding down really fast. In nations where income inequality is in better balance and where they have a decent social safety net, says Keating, families don’t feel like they are always on the edge of some cliff, that if something goes wrong, things could deteriorate in a hurry.

When I met Mia, she was distressed about needing a cesarean, worried that if she took off work for a few extra days to recover, she might lose her job at McDonald’s.

Mia lives, works and parents in the only industrialized nation without a federally mandated paid parental leave program. She wasn’t one of the lucky 14 percent of private sector employees to have paid leave for the birth or adoption of a baby. Mia has had to figure out how to survive economically through the births of each of her children, and navigate the financial stressor of child care. In every region in the U.S., costs for a year of childcare are approximately twice the price of a year’s in-state tuition at public college.

No one can say what degree of adversity tips a child’s experience from tolerable stress to the toxic levels that can set that child on a path to high stress reactivity. But we know that responsive care from adults keeps babies’ stressful experiences from reaching toxic levels. The lack of value placed on caring for children in the U.S. amplifies the overall anxiety felt by new parents and it is impossible to consider the impact of stress on fetuses and young babies without taking into account the pressures on their families.

If Julian’s birth mother had resided in a nation with a livable minimum wage and affordable health care, if she could count on paid leave from her job for six months to a year and reasonably priced childcare once she returned to work, would she have given up her baby? And even if she had decided for adoption, would the overall strain on her family have been less and would Julian have had an easier start, possibly making it closer to term, possibly with his developing nervous system in better shape?

In a nation that neglects its own families, interrupting the cycle of stress dysregulation is not a project that will be accomplished by individual—and probably stressed—families with young children. Instead, it will require a raft of social policies that reduce income stratification and support families around the time of the birth or adoption of a new baby, along with a broad re-valuing of care.

With evidence of an accelerating stress epidemic in the U.S., lowering the strain on America’s harried families is a crucial step toward reducing the number of children whose lives are burdened by relentless anxiety that disrupts learning, health and the ability to take life’s setbacks in stride. While it’s true that the rising generation of Americans won’t remember their earliest adverse experiences, if they aren’t adequately nurtured through their formative first year, their bodies will.

*Names have been changed to protect privacy

This article originally appeared on

Mary Esther Malloy, M.A., is the owner of Mindful Birth NY. She has attended over 600 births as a doula in NYC and teaches Mindfulness-based Childbirth and Parenting classes. A parent of three children, she writes frequently about birth and parenting.