How Common Is SIDS & Recommendations for Reducing the Risks


Over the years, scientists have tried in vain to put a definite finger to the cause of crib deaths. SIDS is thought to be the leading cause death of healthy infants more than one-month-old. SIDS attacks infants up to 12 months old. Premature babies are the most vulnerable of all. One very interesting fact is that SIDS rarely affects infants before one month of age.


What is SIDS?

Sudden Infant Death Syndrome (SIDS) is a medical disorder which claims the lives of thousands of young children one week to one year of age. Once known as crib death, these infant deaths remain unexplained after all known causes have been ruled out through autopsy, death scene investigation, and medical history. SIDS can affect families of all races, religions, and income levels. It usually occurs during sleep, and strikes without warning. Its victims appear to be healthy. Neither parents nor doctors can tell which babies will die.

What Causes SIDS?

We do not know how or why SIDS happens. The first year of life is a time of rapid growth and development when any baby may be vulnerable to SIDS. It is likely that SIDS may be caused by a subtle developmental delay, an anatomical defect, or a functional failure. Challenges a normal baby can overcome – such as passive smoke exposure, stomach sleeping, or overheating – may pose an added, if not fatal risk to an infant who is already vulnerable, and may contribute to a SIDS death.

Researchers ask questions about how babies who die from SIDS might be different from babies who do not. These differences are often referred to as risk factors. Risk factors are not causes of SIDS, but they may be clues about what causes SIDS. Statistics tell us that more babies die of SIDS during the cold weather months. Babies who sleep on their stomachs have an increased risk of SIDS. We also know that more babies die of SIDS whose mothers smoked during and after pregnancy. The younger the mother, the greater baby’s risk for SIDS. Boys are at slightly higher risk than girls. And SIDS occurs most often in infants two to four months of age. In fact, 90% of all SIDS babies are under six months of age. There is also a higher likelihood of SIDS among premature and low-birthweight infants, twins and triplets.

Can SIDS Be Prevented?

Despite some recent claims, there is no product that can stop SIDS from happening. Scientists are exploring the development and function of the nervous system, the brain, the heart, breathing and sleep patterns, body chemical balances, autopsy findings, and environmental factors. SIDS, like other medical disorders, may eventually have more than one explanation and more than one means of prevention. This may explain why the characteristics of SIDS babies seem so varied.

The real headway is being made in identifying factors that may be associated with SIDS. Studies from around the world have now identified risk factors which, though not causes of SIDS in and of themselves, seem to play a role in some cases.


Recommendations for Reducing the Risks for SIDS

We share the following recommendations with you in the interest of providing parents with the latest medical evidence from the U.S. and other countries – in the hope of giving your baby the best possible chance to thrive.

Steps Parents Can Take

baby on the back to sleep

Place your baby on the back to sleep.

The American Academy of Pediatrics recommends that healthy infants sleep on their backs at night and naptime to reduce the risk for SIDS. Since nearly one-third of all SIDS deaths occur in daycare settings, the Academy urges parents to extend this advisory to grandparents, babysitters, daycare providers and everyone who cares for the infant. Babies are not more likely to choke while sleeping on their backs. Delays in rolling over, however, are normal among babies who sleep on their backs. Some infants may experience head-flattening from too much time on their backs or in car seats, a condition which can usually be resolved by simply allowing more tummy-down time when the baby is awake and being watched. Infants unexpectedly falling asleep on their tummies should be gently turned onto their backs. While the side sleep position is preferable to tummy-down, research continues to demonstrate that back is best. The SIDS Alliance does not endorse the use of wedges or other purchased items intended to prop a baby on its side. Parents should discuss sleep positioning of infants with breathing problems or excessive spitting up with the baby’s doctor.

Stop smoking around your baby

Stop smoking around your baby.

Findings from the National Center for Health Statistics demonstrate that women who smoke cigarettes during or after pregnancy put their babies at increased risk for SIDS. Babies exposed to smoke only after birth were twice as likely to die from SIDS as those whose mothers did not smoke at all. And, mothers who smoked both during and after pregnancy tripled their babies’ risk for SIDS. Recent studies have found that the risk of SIDS rises with each additional smoker in the household, the numbers of cigarettes smoked a day, and the length of the infant’s exposure to cigarette smoke. Components of smoke are believed to have a negative impact on the infant’s developing lungs and nervous system and to cause abnormalities in the developing brain. Smoke exposure may also disrupt the arousal mechanism in infants, interfering with a baby’s ability to wake from sleep. Parents are advised not to smoke during pregnancy and the critical first year of life, and not allow anyone else to smoke around the baby either!


Use firm, flat bedding.

The U.S. Consumer Product Safety Commission has issued advisories for parents regarding hazards to infants sleeping on top of beanbag cushions, sheepskins, sofa cushions, pillows or other soft bedding, such as blankets or comforters. Blankets and bumpers should be thin, flat and fastened securely to minimize the risk of covering the baby’s head or face. Your baby’s sleep safety may also be enhanced by positioning your baby for sleep on the back, “feet to foot,” with feet at the foot of the bed (not centered in the crib) and blankets fastened under the sides of the mattress at armpit level to reduce the likelihood of an infant crawling under the bedcovers. Waterbeds have been identified as unsafe for an infant’s sleep. And now a new study indicates that sleeping on a cloth or foam-covered mattress previously used by another child or adult may increase the risk of SIDS. Parents are advised to use a firm, flat mattress in a safety-approved crib, without a pillow, for their baby’s sleep. Be sure to discuss the safety of any second-hand, hand-me-down, or family heirloom cribs, cradles or other bedding items with your baby’s doctor before using them for your baby.


Avoid overheating your baby.

SIDS is associated with the presence of colds and infections; although colds are not more common among babies who die of SIDS than babies in general. Now, research findings indicate that overheating – too much clothing, too heavy bedding, and too warm a room – may increase the risk of SIDS for a baby who sleeps on the stomach, particularly if the baby is ill. Signs that your baby may be overheated include sweating, damp hair, heat rash, rapid breathing, restlessness, and fever. To help your baby regulate his or her temperature, some pediatricians recommend consistent indoor temperatures of 68 to 70 degrees Fahrenheit; and dressing your baby in as much or as little as you would wear. Parents are also advised to avoid using a blanket or other covering directly over your baby’s head or face like a sun or weather screen, particularly when the baby is sleeping in a stroller or car seat.


Take good care of yourself and your baby.

Maintaining good prenatal care and communication with your health care professional about changes in your baby’s behavior and health are of the utmost importance. Breastfeeding has been shown to be good for your baby. The benefits gained from breastfeeding your baby include building up baby’s immunity against illness and infections. Parents are also advised to follow proper immunization schedules for their baby. The risk of leaving a child unprotected against such dangerous diseases as tetanus or whooping cough is 1,000 times greater than any risk posed by using the vaccines. While there is a coincidence of time frame, studies by the National Institutes of Health have turned up no connection between immunizations and SIDS. In fact, SIDS occurs among infants who never received their shots, as well as in countries with different immunization schedules.


Some new concerns about bedsharing.

Bedsharing has not been proven to be protective against SIDS and, according to the American Academy of Pediatrics, may under some conditions be hazardous. The same recommendations for safest sleep conditions apply whether your baby sleeps alone in a crib or shares a bed with you: provide a smoke-free environment for your baby and make sure that your baby sleeps on his or her back on a firm, flat mattress without a pillow, comforter or other soft item under the baby or covering the baby’s head or face. While bedsharing boosts breastfeeding and promote the bond between a mother and infant, bedsharing with brothers or sisters or relatives other than the baby’s mother and father is not recommended. Parents may wish to discuss bedsharing with your baby’s doctor.

Questions And Answers


What is Sudden Infant Death Syndrome (SIDS)?

A: SIDS is the diagnosis given for the sudden death of an infant under one year of age that remains unexplained after a complete investigation, which includes an autopsy, examination of the death scene (Center for Disease Control and Prevention -guidelines), and review of the symptoms or illnesses the infant had prior to dying and any other pertinent medical and family history. Because most cases of SFDS occur when a baby is in a crib sleeping, SIDS is sometimes called “crib death.”

What causes SIDS?

A: There is mounting evidence that suggests some SIDS babies are born with brain abnormalities that make them vulnerable to sudden death during infancy. Studies of SIDS victims reveal that many SIDS infants have abnormalities in the “arcuate nucleus,” a portion of the brain that is involved in control of breathing and waking during sleep. Babies born with defects in other portions of the brain or body may also be more prone to a sudden death. These abnormalities may stem from prenatal exposure to a toxic substance, or lack of a vital compound in the prenatal environment, such as sufficient oxygen.

When is SIDS most likely to occur?

A: SIDS is the leading cause of death in infants between 1 month and 1 year of age. Most SIDS deaths occur when a baby is between 1 and 4 months of age. The risk of SIDS then diminishes during the first year of life.

Are there any infants that are more at risk for SIDS?

A: Yes, infants in the following categories are at a higher risk for SIDS:

  • Infants born to mothers who are less than 20 years old at the time of their first pregnancy
  • Babies born to mothers who had no or late prenatal care Premature or low birth weight babies
  • Babies born to mothers who smoke during or after pregnancy
  • Infants who are placed to sleep on stomach

Are any ethnic groups more prone to SIDS?

A: African American infants are nearly two and a half times more likely to die of SIDS than white infants, and Native American babies are approximately three times as likely to die from SIDS. The NICHD Back to Sleep campaign is being stepped up, with a special effort to get the message out to these two populations.

Is SIDS inherited?

A: Research indicates that there may be a heritable component to SIDS, but its contribution has not proven to be strong. It may be something that genetically predisposes an infant to higher SIDS risk. Metabolic disorders, which can be inherited, have been mistaken for SIDS. One such disorder, medium chain acyl-CoA dehydrogenase deficiency, prevents the infant from properly processing fatty acids. A build-up of these acid metabolites could eventually lead to a rapid and fatal disruption in breathing and heart functioning. If there is a family history of this disorder or childhood death of unknown cause (especially more than one case within a family), genetic screening of parents by a blood test can determine if they are carriers of this disorder. If one or both parents is found to be a carrier, the baby can be tested soon after birth. This is another reason why the autopsy is so important. Tests can be done on the tissues of an infant to identify known metabolic disorders.

Haven’t there been other stories of misdiagnoses in the news lately?

A: Recent reports indicate that some SIDS deaths may not actually be SIDS, but might be attributed to hemorrhaging in the lungs (pulmonary hemosiderosis). On January 17, 1997, scientists at the National Centers for Disease Control and Prevention (CDC) reported in the Morbidity and Mortality Weekly Report that a cluster of infants in Cleveland have been diagnosed with pulmonary hemosiderosis, a respiratory illness. Pulmonary hemosiderosis has been associated with the presence of toxin-producing air-born fungal spores that can grow in waterlogged homes. The local coroner examined all deaths among infants under one year of age and found that a very small number thought to have died from SIDS actually had pulmonary hemosiderosis. CDC researchers, working with coroners around the country, are initiating a study to determine how many previous infant deaths could be attributed to pulmonary hemosiderosis and wet moldy basements.

Do you have any estimates on how often SIDS is a misdiagnosis?

A: Estimates from a few studies have shown that misdiagnoses account for a very small percentage of SIDS deaths. In a 1994 policy statement, the American Academy of Pediatrics (AAP) estimated that cases of sudden infant death thought to be SIDS were correct 95-98% of the time.

There have been recent stories in the news suggesting that some cases of SIDS have been misdiagnosed and may be hidden cases of abuse and infanticide. What is the evidence for this?

A: A new book, The Death Innocents (Bantam) by Richard Firstman and Jamie Talan, recounts the story of a mother indicted for the murder of her children approximately a quarter of a century after their deaths had been labeled as SIDS. Giving other instances where suspicious infant deaths and injuries may not have been thoroughly investigated, the authors interview Thomas L. Truman, M.D, a pediatrician who reviewed the Massachusetts General Hospital’s medical records over a 20 year period and claimed that a third of 155 apparent life threatening events (ALTEs) had suspicious circumstances and should be investigated for possible abuse. While Truman has stated he will be publishing this report in Pediatrics, there is no schedule for its release at this time.Another study, by David Southall, to be published in the November issue of Pediatrics, reports on evidence (from England between June 1986 and December 1994) of 39 cases where covert video surveillance was used to investigate suspicions of parentally-induced illness. Abuse was revealed in 33 of the 39 cases, out of a total of 252 patients referred to the participating hospitals. The study indicates, however, that “these figures cannot provide a true epidemiological indication of the frequency of intentional suffocation” because there was an increase in case referrals due to practitioner knowledge of the study.

Some of the parents in Southall’s study showed signs of Munchausen by proxy, a mental disorder in which the parent, almost always a mother, either fabricates illness in their children or actually induces symptoms of illness through various forms of physical abuse.

None of the infants in this study died, however, they were removed from the care of the abusive parent. Some of the infants had siblings who has been diagnosed as dying of SIDS, and in several of these instances, when abuse of a living child was confirmed, the mother admitted to having suffocated the infant originally diagnosed as having died of SIDS.

This evidence only reiterates the need to fully investigate, on a case by case basis, each instance of a sudden infant death and to consider the many possible causes of death, including but not limited to SIDS, congenital anomalies, metabolic disorders, unintentional injuries, child abuse, and infections.

To prevent this confusion, aren’t there any state or national guidelines for investigating the sudden death of infants?

A: In 1993, the Interagency Panel on SIDS held a meeting to develop guidelines for death scene investigation of sudden unexplained infant deaths. A death scene investigation is an integral part of a SIDS diagnosis to rule out accidental, environmental, and unnatural causes and to provide information to researchers on risk factors for SIDS. In June 1996, the Panel published a model protocol and data form for collection of information by medical examiners, coroners, death team investigators, and police officers. Although state and local ordinances define which deaths must be investigated and the extent of the investigation, these guidelines set the stage for uniform death scene investigation around the country.Currently, approximately half of the states have mandatory autopsy legislation for the sudden death of an infant which, in many cases, includes support for the administration of compassionate services for SIDS families. Other states are in the process of establishing similar legislation. NICHD encourages each state to adopt some mandatory autopsy legislation.

Is enough research being conducted to determine the cause of SIDS?

A: SIDS has been a high priority for research for the National Institute of Child Health and Human Development (NICHD) at the National Institutes of Health (NIH). Although SIDS deaths are decreasing, it is important that NICHD continue to support research aimed at uncovering what causes SIDS, who is at risk for the disorder, and ways to lower the risk of sudden infant death. The importance of understanding the causes of SIDS is only underlined by its recent place in the headlines. The more we learn about SIDS, the more easily we will be able to distinguish SIDS from other infant deaths, and perhaps even one day be able to predict more accurately which babies are at highest risk.

Does NlCHD support any research on home monitors?

A: Among the many avenues of research initiated by the NICHD, infant monitoring was thoroughly investigated by NICHD-funded researchers. In the 1970’s and early 1980’s, it was thought that monitoring had promise in identifying infants at risk for SIDS and signaling caregivers when infants have life-threatening events that may proceed to SIDS. In September of 1986, the NICHD held a consensus conference titled, “Infantile Apnea and Home Monitoring.” After examining all available research, the consensus panel determined that cardiorespiratory monitoring is effective only in some cases to manage apnea. For the normal newborn, the risks, disadvantages, and costs of monitoring outweigh the potential of identifying infants at risk for SIDS.Today, NICHD funds the Collaborative Home Infant Monitoring Evaluation (CHIME ), a multi-center study initiated in 1991 that employs a specifically commissioned monitor with multiple innovative capabilities, including substantially increased memory, detection of obstructive as well as central apnea, continuous measurement of blood oxygen saturation, and assessment of sleep position. The CHIME project will create an extensive database (which will be made available to the scientific community) on the development of cardiorespiratory physiology in normal and in at risk infants. In this context, the study should yield important new insights regarding the frequency and nature of clinically significant events as related to breathing pattern, heart rate, and oxygen saturation.

Then, NICHD does not recommend the use of monitors to prevent SIDS?

A: Although some electronic home monitors detect and sound an alarm when a baby stops breathing, there is no evidence that such monitors prevent SIDS. The monitors also pose several disadvantages, including frequent false alarms, restricted mobility of both infant and parents, and the risk of electrical injury to young children.A panel of experts convened by the National Institutes of Health recommended that home monitors not be used for babies who do not have an increased risk of sudden unexpected death. However, the monitors may be recommended in some cases including for infants who have experienced one or more severe episodes during which they stopped breathing and required resuscitation or stimulation, if the baby is premature and has symptomatic apnea, or if the baby has a medical condition such as central hypoventilation. If an incident has occurred or if an infant is on a monitor, parents need to know how to properly use and maintain the device as well as how to resuscitate their baby if the alarm sounds.

Is there anything we can do to prevent SIDS?

A: There currently is no way of predicting which newborns will succumb to SIDS. However, there are a few measures parents can take to lower the risk of their child dying from SIDS.

  • Back Sleeping. Placing babies on their backs to sleep is the single most important step that parents and other caregivers can take to reduce the risk of SIDS. Studies have shown that countries, where caregivers have switched from placing babies on their stomachs to sleep to placing babies on their backs to sleep, have reduced their total SIDS deaths by as much as 50 percent.
  • Bedding. Parents should make sure their baby sleeps on a firm mattress or other firm surface. Caregivers should also avoid using fluffy blankets or coverings and should not use pillows, sheepskins, or comforters under the baby. Infants under 1 year of age should not be placed to sleep on a waterbed or with soft stuffed toys.
  • Prenatal Care. Good prenatal care–including proper nutrition, abstinence from alcohol, drugs, and smoking, and frequent medical check-ups beginning early in pregnancy–might help prevent a baby from developing an abnormality that could put him or her at risk for sudden death.
  • Smoking. Mothers who smoke during pregnancy are three times more likely to have a SIDS baby, and exposure to passive smoke from smoking by mothers, fathers, and others in the household after pregnancy doubles a baby’s risk of SIDS. Parents should be sure to keep their babies in a smoke-free environment.
  • Room Temperature. Babies should be kept warm, but they should not be allowed to get too warm. An overheated baby is more likely to go into a deep sleep from which it is difficult to arouse. Keep the temperature in the baby’s room at a level that feels comfortable to an adult and avoid overdressing the baby.
  • Breast Feeding. There is some evidence to suggest that breastfeeding might reduce the risk of SIDS. A few studies have found SIDS to be less common in breastfed infants than those bottle-fed. This may be because breast milk can provide protection from some infections that can trigger sudden death in infants.
  • Regular Health Care. Parents should take their babies to their health care provider for regular well-baby check-ups and should make sure that their babies receive their immunizations on schedule.
Are there any advantages or disadvantages to “shared sleeping” arrangements?
A: Scientific studies have demonstrated that bedsharing, between baby and mother, can alter sleep patterns of mother and baby. These studies have led to speculation in the lay press that bedsharing or “co-sleeping” may also reduce the risk of SIDS. While bed-sharing may have certain benefits (such as encouraging breastfeeding), there are no scientific studies demonstrating that bed-sharing reduces SIDS. Conversely, there are studies suggesting. that bedsharing, under certain conditions, may actually increase the risk of SIDS. There is no basis at this time for encouraging bedsharing as a strategy to reduce SIDS risk.

Won’t my baby choke on spit-up or vomit during sleep if placed on its back?

A: Many parents place babies on their stomachs to sleep because they think it prevents them from choking on spit-up or vomit during sleep. But studies in countries where there has been a switch from babies sleeping predominantly on their stomachs to sleeping mainly on their backs have not found any evidence of increased incidence of aspiration pneumonia, choking, or other problems. In addition, the American Academy of Pediatrics has reviewed all the scientific literature and found that there is no additional risk of choking on vomit when babies sleep on their backs.

Which babies should not be placed on their backs to sleep?

A: In some instances, doctors may recommend that babies be placed on their stomachs to sleep if they have disorders such as gastroesophageal reflux or certain upper airway disorders that predispose them to choking or breathing problems while lying on their backs. If parents are unsure about the best sleep position for their baby, it is always a good idea to talk to the baby’s doctor or other health care provider.

Should infants ever be placed on their tummies?

A: A certain amount of “tummy time” while the infant is awake and being observed is recommended for motor development of the shoulder. In addition, awake time on the stomach may help prevent flat spots from developing on the back of the baby’s head. Such physical signs are almost always temporary and will disappear soon after the baby begins to sit up.

Should sleeping “wedges” be used for infants?

A: The NICHD does not have a position on the use of “wedges” as no studies of their safety or efficacy have been done.

How does a SIDS baby affect the family?

A: A SIDS death is a tragedy that prompt intense emotional reactions among surviving family members. After the initial disbelief, denial, or numbness begins to wear off, parents often fall into a prolonged depression. This depression can affect their sleeping, eating, ability to concentrate, and general energy level. Crying, weeping, incessant talking, and strong feelings of guilt or anger are all normal reactions.Many parents experience unreasonable fears that they, or someone in their family is in danger. Over-protection of surviving children and fears for future children is a common reaction. As the finality of the child’s death becomes a reality for the parents, recovery occurs. Parents begin to take a more active part in their own lives, which begin to have meaning once again. The pain of their child’s death becomes less intense but not forgotten. Birthdays, holidays, and the anniversary of the child’s death trigger periods of intense pain and suffering.

Children will also be affected by the baby’s death. They may fear that other members of the family, including themselves, will also suddenly die. Children often also feel guilty about the death of a sibling and may feel that they had something to do with the death. Children may not show their feelings in obvious ways. Although they may deny being upset and seem unconcerned, signs that they are disturbed include intensified clinging to parents, misbehaving, bed wetting, difficulties in school, and nightmares. It is important to talk to children about the death and explain to them that the baby died because of a medical problem that only occurs in infants and in rare instances.




Photos: Pixabay

National Institute Of Health

National Center for Health Statistics

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