Despite decades of effort, babies are still dying from SIDS
About 3,400 babies under the age of 1 year still die suddenly and unexpectedly every year. Of these, the number of infant deaths officially attributed to SIDS is likely an underestimate, experts say. In most cases, parents find that their baby is unresponsive in the crib — and autopsy procedures aren’t standardized — so most of these heartbreaking deaths remain mysterious and aren’t always classified as SIDS.
“That [SIDS] rates have been completely flat for the past 20 years,” says Fern Hauck, associate professor of family medicine and public health at the University of Virginia School of Medicine and SIDS researcher. “I think it’s important that public health professionals are aware that those numbers aren’t going down.”
Experts say it’s important to reinforce safe sleep messages among new parents and to speed up research into possible physiological factors — for example, genetic and brain abnormalities — that could impair an infant’s ability to wake themselves up if their baby’s breathing is disrupted child goes wrong.
Genetics may predispose some babies to SIDS, or “crib death,” says study
The cause of some deaths is obvious – such as accidental strangulation or suffocation, for example, when a baby’s head becomes trapped between the mattress and the side of the cot. But in most cases, the cause is unknown.
Most academic and clinical researchers still prefer the term SIDS for these infant deaths, but the U.S. coroner’s community — coroners and medical examiners — tends to label them as unknown or indeterminate.
Such practices have made SIDS numbers appear smaller than they are, experts say argue that the terminology needs to be more consistent to get an accurate picture. The Centers for Disease Control and Prevention also use it graphic which contain separate statistics for SIDS and unknown cause categories.
“If you just look at death certificates that say SIDS, they’ve gone down dramatically, but the reality is that many of the deaths that aren’t labeled as SIDS would have been considered SIDS before 1992,” says Carl Hunt, research professor of Pediatrics at the F. Edward Hébert School of Medicine at Uniformed Services University in Bethesda, Maryland and Chairman of the Board of American SIDS Institute. “They are now part of the larger total of [unknown cause] deaths.”
“SIDS is underestimated,” says Hauck. “It doesn’t go away. They just changed the name.”
She and others say it’s time to find new ways to re-emphasize safe sleep advice — she’s creating short videos for hospitals and doctors, for example, to share with new parents — and find out why some parents are stopped following them. In addition to back-sleeping in a crib with nothing but a firm mattress and the baby, experts are urging parents to avoid bed-sharing and smoking while pregnant and around the infant. Breastfeeding (always with the baby sleeping in the cradle afterwards), providing a pacifier (but not on a string or cord), and keeping the cradle in the parents’ room are measures that appear to reduce the risk, according to the American SIDS Institute.
SIDS deaths are declining, but many infants still do not sleep on their backs
Still, Hauck says, sleep-deprived parents sometimes ignore the advice.
“People make decisions in the middle of the night when the baby is crying and they’re exhausted,” she says. “So they take the baby to bed or put him on his stomach because they may have heard from a friend that this will calm the baby down. When a baby is first placed on his stomach, he is more likely to die. They’re not used to being in that position, and when they get into trouble, their brain doesn’t tell them to react properly.”
Marion Koso-Thomas, program scientist at the Eunice Kennedy Shriver National Institute of Child Health and Human Development’s Global Network for Women’s and Child Health Research, points out that the internet is rife with misinformation about unsafe sleep products and ineffective monitoring devices.
“We’ve got new generations of parents coming online and seeing websites with new devices like Bumpers and thinking, ‘That’s cool, I’m going to try this with my baby.’ And it may not be safe,” she says. “With social media, they have a whole new world to pull information from, and some of it is alarming.”
Additionally, parents may get advice from sources who still believe in traditional but outdated practices, she says.
“There are caregivers and grandparents where culture plays a role and they influence the mother’s decisions,” says Koso-Thomas, adding that pediatricians are an important resource for new parents and should be confident in sharing information about safe sleep.
“We hoped that pediatricians would be among the most passionate advocates of safe sleep, but sometimes they just don’t have the time,” she says. “It’s not just that people don’t hear it, it’s that they don’t hear it from the right people.”
“Many parents are aware of this, but every generation needs to be educated,” says Michael Goodstein, department head of neonatal medicine at WellSpan Health and clinical professor of pediatrics at Pennsylvania State University. “There are grandparents who were told in their day to let their babies sleep on their stomachs, and they can influence parenting decisions.”
Beyond strengthening public messages, scientists also want to expand research into physiological factors common to children with SIDS, with the future goal of identifying babies at risk in advance.
“We learn more every year,” says Hunt. “We know there is a familial risk – parents whose baby has died are at a higher risk of having another. And a lot of the genetic studies point to the brainstem, the area of the brain that controls automatic functions like breathing and heart rate control [which affect] … arousal, the last protective mechanism that seems to fail in infants who die suddenly and unexpectedly.”
Studies have already identified genetic variants among SIDS deaths related to cardiac, respiratory and neurological functions, among others, and abnormalities of the brain that can affect arousal. Researchers believe the cause of death stemmed from a lack of arousal.
“I put a healthy baby to sleep on his stomach [stomach] position and it begins to breathe back the air it exhaled,” says Jan-Marino (Nino) Ramirez, director of the Center for Integrative Brain Research at Seattle Children’s Hospital, which studies SIDS and brain function. “Carbon dioxide rises and the baby begins to experience hypoxia [or insufficient oxygen]. A normal cardiorespiratory system responds and the baby wakes up. With SIDS, there is a malfunction in this system.”
Swaddling babies is associated with an increased risk of sudden infant death syndrome
Ramirez believes SIDS results from a combination of environmental and physical factors.
“There are certain genes associated with the heart and excitatory systems and the immune system that affect the brain,” he says. “None of these genes alone are lethal. Then an external stressor—putting the baby in a sleeping position—reveals the weakness. When the baby has to wake up, it cannot, and the defect becomes obvious. That’s why the “Back to Sleep” campaign made an impact. The babies who didn’t have to wake themselves survived.”
SIDS experts say 3,400 deaths a year is still too many.
“A lot of new moms feel like ‘this can’t happen to me,’ so they may not follow all the recommendations, but it can happen to anyone,” says Hauck. “We don’t want it to happen to anyone. It’s rare. But if it happens to you, it’s 100 percent.”
She recalls an experience in 1995 when she was just beginning her SIDS research. She took a call from a woman who had lost a baby to SIDS. It was the anniversary of the child’s death and the grieving mother needed to speak to someone.
“She really had problems,” says Hauck. She remembers asking the woman when her baby died. The answer shook her. “She said 25 years ago,” says Hauck.
The message still haunts her today: “Once you lose a baby to SIDS, it never goes away.”