Sudden Infant Death Syndrome: Trying to Understand the Mystery

Developed by the National SIDS/Infant Death Resource Center as a basic information resource for health professionals, social service personnel, others who provide support, and families, Sudden Infant Death Syndrome: Trying to Understand the Mystery (February 1994) addresses many of the complex issues surrounding SIDS and summarizes findings from various research efforts as scientists attempt to understand this syndrome and its consequences.

INTRODUCTION

The death of an infant is a catastrophic loss to both the family and society. An infant's life ceases before he[she] can think and love and achieve his[her] unique human potential (Shannon, 1980).

What is sudden infant death syndrome (SIDS)? What makes a SIDS death so different from other infant deaths? Why do apparently healthy infants die? Why are researchers so dedicated to discovering the cause of SIDS? Why are health professionals so concerned with handling the consequences? Why are parents so bewildered and bereft?

The suddenness and unexpectedness of the tragedy make a SIDS death especially difficult, leaving a great sense of loss and a need for understanding. Families, professionals involved in caring for families with SIDS losses, and even the community often are left with a sense of sadness and a feeling that something could have been done to prevent the death.

At this time SIDS cannot be prevented. Researchers are still unclear about its causes. The strongest weapons in waging the battle against ignorance and confusing or incorrect reports about SIDS are education and accurate, up-to-date information.

Developed as a basic information resource for health professionals, social service personnel, others who provide support, and families, Sudden Infant Death Syndrome: Trying to Understand the Mystery addresses many of the complex issues surrounding SIDS and summarizes findings from various research efforts as scientists attempt to understand this syndrome and its consequences.

• the major cause of death in infants from 1 month to 1 year of age, most deaths occurring between 2 and 4 months.
• sudden and silent--the victim was seemingly healthy.
• currently, unpredictable and unpreventable.
• a death that occurs quickly, with no signs of suffering, and is usually associated with sleep.
• a syndrome the first symptom of which is death.
• determined only after an autopsy, an examination of the death scene, and a review of the case history.
• a diagnosis established by exclusion.
• a recognized medical disorder listed in the International Classification of Diseases, 9th Revision (ICD-9).
• an infant death that leaves unanswered questions and, thus, causes intense grief for parents and families.

• caused by vomiting and choking, or minor illnesses such as colds or infections.
• caused by the diphtheria, pertussis, tetanus (DTP) vaccines, or other immunizations.
• contagious.
• child abuse.
• the cause of every unexpected infant death.

As long as its cause or causes remain unknown, sudden infant death syndrome will be a puzzle for researchers, and SIDS deaths will continue to be mysterious and tragic for parents and families.

COMMONLY ASKED QUESTIONS ABOUT SIDS

..SIDS remains an unpredictable, unpreventable and unexplainable tragedy--a situation in which we are unable to do anything for the infant who has died....SIDS demands that we unravel its mystery, find its cause or causes, and learn how to prevent it from happening
(Corr, 1991).

Many of the questions about what causes sudden infant death syndrome (SIDS) or how to prevent it are still unresolved. The mysterious and elusive nature of SIDS creates problems, doubts, and more questions. This section presents some of the most commonly asked questions as well as the answers that have been uncovered by scientists after years of research and study.

Exactly What Is SIDS?

SIDS Definitions of 1969 and 1989

In 1969, researchers agreed to define SIDS as "the sudden death of an infant or young child, which is unexpected by history, and in which a thorough postmortem examination fails to demonstrate an adequate cause of death" (Bergman, 1970). In 1989, the National Institute of Child Health and Human Development (NICHD) amended the definition to read "the sudden death of an infant under one year of age which remains unexplained after a thorough case investigation, including performance of a complete autopsy, examination of the death scene, and review of the clinical history" (Willinger, et al., 1991).

International SIDS Definition

In addition, members of the SIDS community (researchers, health care professionals, and parents) worldwide are working together to construct a universally acceptable definition of SIDS. An international definition is necessary for multinational research efforts and to promote uniform service delivery. The heterogeneity in the structure of the health care and forensic systems around the world was the stimulus for considering alternatives to existing definitions. At the SIDS International meeting in Sydney, Australia, in 1992, Dr. Marian Willinger (Health Scientist Administrator, SIDS Research Program, NICHD) and Dr. Stephen Cordner (Director, Victorian Institute of Forensic Pathology, Australia) were given the responsibility for the development of the international SIDS definition and the procedures for its review and implementation. These recommendations will be presented at the next SIDS global strategy meeting, to be held in Stavanger, Norway, in July 1994.

What Causes SIDS?

The cause or causes of SIDS are still unknown. Most researchers now believe that babies who die of SIDS are born with one or more conditions that make them vulnerable to both internal and external stresses that occur in the normal life of an infant.

What Are the Most Common Characteristics of SIDS?

SIDS occurs in all types of families and is largely indifferent to race or socioeconomic level. SIDS is unexpected, usually occurring in otherwise apparently healthy infants from 1 month to 1 year of age. Most SIDS deaths occur by the end of the sixth month, the greatest number taking place between 2 and 4 months of age. A SIDS death occurs quickly, with no signs of suffering, and is usually associated with periods of sleep. More deaths are reported in the fall and winter in both the Northern and Southern Hemispheres. There is a 60- to 40-percent male-to-female ratio. A death is diagnosed as SIDS only after all other recognizable causes of infant death have been eliminated: SIDS remains a diagnosis of exclusion.

Medical researchers have identified some typical pathological characteristics of SIDS deaths that indicate that the sudden infant death syndrome is a distinct clinical occurrence. For example, pathologists have noted several subtle tissue changes common in SIDS autopsies. Two of these changes are particularly intriguing--the increased number of star-shaped cells in the brainstem, referred to as brainstem gliosis, as a "non-specific response to injury" (Goyco and Beckerman, 1990) and the occurrence of tiny red or purple spots (minute hemorrhages) on the surface of the heart, in the lungs, and thymus. These spots (or petechiae) have been identified in approximately 80 percent of SIDS cases (Krous, 1988).

What Are the Risk Factors for SIDS?

Experts still cannot predict which babies will die from SIDS, but recent research has provided direction for identifying those infants who may have an increased risk of dying from SIDS.

Risk factors are those environmental and behavioral influences that can provoke ill health. Any risk factor may be a clue to finding the cause of a disease, but risk factors, in and of themselves, are not causes. For example, because as many as 80 percent of SIDS deaths occur by the age of 6 months, infants in this age group are considered to be at increased risk (Peterson, 1984). Obviously, age is not a cause of death, but this information serves as a clue to scientists as they try to detect a link between SIDS and any one or more of those behavioral and physiological phenomena that take place within that period in a baby's development.

Researchers know that the mother's health and behavior during her pregnancy and the baby's health before birth seem to influence the occurrence of SIDS, but these variables are not reliable in predicting how, when, why, or if SIDS will occur. Maternal risk factors include cigarette smoking during pregnancy, maternal age less than 20 years, poor prenatal care, low weight gain, anemia, use of illegal drugs, and history of sexually transmitted disease or urinary tract infection. These factors, which often may be subtle and undetected, suggest that SIDS is somehow associated with a harmful prenatal environment.

Although the relationship between these factors and SIDS is not yet clear, refraining from smoking, eating properly, and obtaining adequate prenatal care are maternal behaviors that will increase the chance for a healthy pregnancy outcome.

Newborn medical risk factors include cyanosis (blue discoloration of skin due to inadequate oxygenation of the blood), tachycardia (accelerated heartbeat), respiratory distress, irritability, hypothermia, poor feeding, and tachypnea (accelerated breathing). These risk factors have been found to occur in a statistically significantly greater number of SIDS infants than non-SIDS infants in the newborn nursery (NICHD, 1988).

Scientists have found that certain factors do not seem to increase the risk for SIDS. Based on reports from parents, SIDS infants do not tend to have more colds or fevers than non-SIDS infants. Data from medical records and interviews with parents strongly suggest that there is no association between the DTP (diphtheria, tetanus, pertussis) vaccination and SIDS. Newborn apnea (temporary stoppage of breathing) does not appear to be a risk factor for SIDS (NIH, 1987). The significance of infantile apnea through the first year of life, however, continues to be the focus of intense scientific investigations.

How Many Babies Die From SIDS?

From year to year, the number of SIDS deaths tends to remain constant despite fluctuations in the overall number of infant deaths. The National Center for Health Statistics (NCHS) reported that in 1988 in the United States, 5,476 infants under 1 year of age died from SIDS, and in 1989 the number of SIDS deaths was 5,634 or 14 percent of all deaths among infants less than 1 year of age (NCHS, 1990, 1992). However, other sources estimate that the number of SIDS deaths in this country each year may actually be closer to 7,000 (Goyco and Beckerman, 1990). The larger estimate represents additional cases that are unreported or underreported (i.e., cases that should have been recorded as SIDS but were not).

When considering the overall number of live births each year, SIDS remains the leading cause of death in the United States among infants between 1 month and 1 year of age and second only to congenital anomalies as the leading overall cause of death for infants less than 1 year of age (NCHS, 1992).

How Do Professionals Diagnose SIDS?

Often, the cause of an infant death can be determined only through a process of collecting information, conducting sometimes complex forensic tests and procedures, and talking with parents and physicians. SIDS is no exception.

Health professionals make use of three avenues of investigation in determining a SIDS death:

1. the autopsy,
2. death scene investigation, and
3. review of victim and family case history.

The autopsy provides gross and microscopic clues as to the cause of death. Although researchers and other legal, medical, and social service professionals differ in their opinions about what constitutes a "thorough" death scene investigation, it should include interviews with the parents, other caregivers, and family members; the collection of significant items from the death scene; and evaluation of that information. A comprehensive history of the infant and family is especially critical when evaluating unexpected infant deaths.

Because of increased attention to the need for accurate and verifiable information regarding each SIDS death, a thorough and detailed investigation of the death scene is a critical element of the postmortem findings. Although painful for the family, a detailed scene investigation may shed light on the cause, sometimes revealing a recognizable and possibly preventable cause of death. Reliable and detailed death scene investigation involves cooperation from the medical examiner; allocation of resources; collaboration from State and local agencies; and cooperation of the victim's family and other caregivers during a time of grief, confusion, and even guilt.

A death scene investigation may convey the implication of wrongdoing or carelessness on the part of the family or care provider. Investigators must be especially sensitive to such issues and understand that the family may view the process as an intrusion, even a violation of their grief. However, it should be noted that, although stressful, a careful investigation that reveals no preventable cause of the baby's death may provide some solace to the grieving family.

A careful review of documented and anecdotal information about the victim's or family's history of previous illnesses, accidents, and behaviors may corroborate findings of the autopsy or death scene investigation. (See the chart concerning the steps in the determination of a SIDS death at the end of this section.)

Why Is an Autopsy Important?

There are two reasons why SIDS health professionals consider an autopsy important. First, as noted earlier, SIDS is a diagnosis of exclusion. A definitive SIDS diagnosis cannot be made without a thorough autopsy and postmortem investigation that is focused on identifying recognizable causes of death in infancy and that fails to point to any other possible cause of death. Second, if a cause of SIDS is ever to be uncovered, scientists will most likely detect that cause, at least in part, through evidence gathered from thorough pathological examinations.

Although parents may feel that an autopsy "violates" their dead infant and depersonalizes their bereavement, it is only through autopsies that all other potential causes of death can be ruled out.

How Is Information About a SIDS Death Collected?

Death certificates are the most common and widely used source of data on SIDS. The accuracy of SIDS mortality information depends on the use of standardized procedures for conducting pediatric autopsies and death investigations as well as the amount of detailed information provided by the attending physician, coroner, or medical examiner who certifies the infant's death.

The reliability of death certificate information depends on how the cause of death is classified and coded, as well as the State laws governing death investigations. The NICHD strongly recommends that a death be recorded as SIDS only after the performance of an autopsy, death scene investigation, and review of the infant and family history. However, in most States autopsies are performed at the discretion of the medical examiner or coroner or at the request of the parents.

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DETERMINING A SIDS DEATH

1. Local emergency medical responders and law enforcement personnel are summoned to the scene after an apparently healthy infant dies suddenly and unexpectedly.
2. Medical personnel attempt to revive infant according to local emergency medical services (EMS) guidelines.
3. Infant is pronounced dead at the scene or after being taken to the nearest emergency care facility.
4. Emergency personnel and police conduct detailed death scene investigation; interview parents, other caregivers, and other family members; collect items from scene of death; evaluate information from scene; and report information to medical examiner.
5. Medical examiner, other medical personnel, or police prepare a detailed infant and family history based on in-depth interview with parents, family, physician, and other relevant parties.
6. Autopsy is performed by medical examiner, coroner, or physician who understands SIDS.
7. All possible causes for the death are ruled out.
8. The cause of death is established following analysis of information obtained from the infant and family case histories, death scene evaluation, and the autopsy.
9. Medical examiner or attending physician signs death certificate designating cause based on the International Classification of Diseases, 9th Revision (ICD-9).

This chart is based on the 1989 NICHD definition of SIDS and represents the sequence of events and responses that should occur in determining a SIDS death.

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Although all States have the legal authority to investigate deaths and conduct autopsies, currently only some have laws specifying procedures for handling possible SIDS deaths. Some States specify that an autopsy is mandatory before SIDS can be designated on the death certificate. Other States are currently developing similar legislation.

In the United States, individual State and local health authorities are responsible for the registration of births, deaths, fetal deaths, and other vital events. Each State is required by law to provide for a "continuous, permanent, and compulsory vital registration system" (NCHS, 1987). These systems depend on the efforts of physicians, hospital personnel, funeral directors, coroners, and medical examiners in preparing or certifying information that is included on vital statistics records.

In most States a local registrar collects the records of events occurring in his/her jurisdiction and transmits them to the State vital statistics office, where they are reviewed, processed, and stored for future safekeeping, reference, and reporting.

Data tapes of information derived from these records are transmitted by the States to the NCHS, a part of the Public Health Service. From these data, the NCHS prepares monthly, annual, and special reports on various characteristics, such as age, race, sex, and cause of death. This information is used by Federal, State, and private social welfare and public health professionals in assessing the impact of certain health phenomena and in planning for future disease prevention and health
promotion efforts.

CURRENT THEORIES AND RESEARCH

To put research concerned with the sudden infant death syndrome (SIDS) into perspective, it is essential to consider the nature of the problem. Unlike other, more tractable, medical conditions there are usually no obvious clues from the infants that something is awry before they are found dead. As with a mystery novel, the investigator is faced with a victim and must search for clues that will lead to a solution (Hasselmeyer and Hunter, in Schwartz, Southall, and Valdes-Dapena, 1988).

Since 1963, health professionals have been probing, studying, and, at times, discarding theories about what causes SIDS or how to prevent such deaths. Scientists have developed specific hypotheses and set up controlled scientific methods for testing and evaluating those hypotheses. Researchers from within the private and public sectors have studied family background, prenatal and birth history, diet, allergies, immunizations, illnesses, behavior and personality, sleeping habits and positions, and the effects of the environment on infant health.

Researchers still do not know what causes SIDS. Scientific efforts have led to the elimination of various early erroneous or misleading theories. For example, it is now known that SIDS is not caused by choking or neglect and that it is not contagious. Recent clinical research findings have tended to substantiate earlier theories attributing SIDS to an array of deficiencies or abnormalities in the newborn that result in an inability to adjust to life outside the womb. By continuing to verify and assess research findings on SIDS victims and normal infants, scientists may be able to understand the variations in the cardiorespiratory, nervous, and immune functions of the normal infant and, by comparing them with SIDS victims, may come closer to solving the mystery that is SIDS.

Although researchers have been unable to pinpoint a specific cause or causes of SIDS, much of what has already been discovered about SIDS has been translated into practical public health measures that have helped to improve general health outcomes for infants. Findings from SIDS research have helped professionals who work with families to ease the pain of their loss. Parents, family members, and other caregivers are afforded some comfort through their increased understanding of the complexities surrounding SIDS.

Since the mid 1970's, various Federal agencies and private organizations have supported a wide array of projects in an attempt to explain what is known about the underlying mechanisms of SIDS to families and others; to identify those infants most at risk of becoming SIDS victims; to develop approaches to preventing SIDS; and to study the relationship between high-risk pregnancy, high-risk infancy, and SIDS. The National Institute of Child Health and Human Development (NICHD), a part of the National Institutes of Health, has primary responsibility for implementing the Federal Government's SIDS research program.

In addition, through the cooperative efforts of State and local health departments, the Maternal and Child Health Bureau, Centers for Disease Control and Prevention, and Indian Health Service are studying and collecting data on the epidemiology and prevention of SIDS. Private organizations, such as the American SIDS Institute, the Association of SIDS Program Professionals, the Maryland SIDS Institute, the SIDS Alliance, the Southwest SIDS Institute, and others, have prominent roles in fostering ongoing SIDS research.

Research Approaches and Strategies

Research on SIDS is complex and relies on intense evaluation and comparison of data from longitudinal studies or projects that match or parallel SIDS cases with non-SIDS cases. Because SIDS is diagnosed through postmortem examination, much of the focus of current research is directed at deriving and analyzing detailed data from information gathered by autopsy.

By studying these data, scientists are attempting to isolate "markers," i.e., specific characteristics or conditions that occur in victims but that are not present in nonvictims. Researchers try to determine the actual mechanism of death, i.e., exactly what happened at the time of death. By defining these markers, researchers hope to identify those infants most at risk of dying from SIDS and develop ways to prevent those deaths. However, because many of the indicators that identify an infant at increased risk for SIDS are also indicators of overall poor health outcomes, this is an extremely complex and arduous task.

Some SIDS research is focused currently on maternal and child health. As mentioned above, one strategy is to study the growth and development of the brain and nervous, cardiac, and respiratory systems in normal infants as well as behavioral and physiological responses of infants to ordinary stresses, in utero and after birth.

Researchers are working on numerous diverse projects that focus on specific aspects of the problem. A few of these are highlighted below.

Areas of SIDS-Specific Research

Epidemiological research

By comparing and analyzing data from populations of normal, premature, or ill infants with infants who died of SIDS, scientists are attempting to detect statistical patterns and trends (epidemiology) that identify specific causal relationships.

Postmortem examination

In 1988, NICHD published the results of the SIDS Cooperative Epidemiological Study. It contained an analysis of case histories from six medical centers throughout the country involving 800 SIDS victims compared with twice as many live infants as matched controls. In 1989, work on a SIDS histopathology atlas was initiated from a microscopic and quantitative analysis of tissue specimens from the same study. The work was published in 1993. This atlas will serve as a reference tool to assist pathologists and forensic personnel in classifying deaths as SIDS based on lack of any other medically explainable cause of death evidenced in the autopsy. Through use of the postmortem examination, scientists have confirmed that pinpoint hemorrhages in the lungs and thymus and production of blood cells in the liver are common in SIDS victims, as are mild inflammation of the upper airway and congestion of the lungs.

Infant apnea and apparent life-threatening event (ALTE).

ALTE is characterized by a combination of apnea, skin color change, obvious change in muscle tone (usually limpness), or choking or gagging. In the past, ALTE was sometimes referred to as "near-miss" SIDS or "aborted crib death." Those terms are no longer used because scientists still differ in their opinions about the relationship of ALTE to SIDS. ALTE is observed in approximately 2 to 3 percent of the general population, twice as frequently as SIDS. However, infants with histories of ALTE episodes and premature infants with histories of apneic episodes comprise only a very small percentage of all SIDS cases. Results from the NICHD SIDS Cooperative Epidemiological Study indicated that there was no evidence that apnea among premature infants increased the risk for SIDS (NIH Consensus Development Report, 1986). Scientists continue to explore the possibility that there is some relationship between the apnea of infancy (or ALTE events) and SIDS.

Biomedical Research

SIDS biomedical research is focused on studies in infants and animals whose early development is similar to that of humans. By understanding the mechanisms that control the function and maturation of various organs, scientists hope to develop preventive measures to be used during critical stages in the infant's development.

Fetal predisposition

Many scientists now maintain that babies who die of SIDS are born with one or more conditions that make them especially vulnerable to internal and external stresses that occur in the normal life of a baby. This hypothesis is considered by many to be the primary contribution of SIDS research in the last 10 years. It is the basis for much of the current research. This type of research is focused on the relationship between these stressful intrauterine occurrences and the underlying characteristics that make certain infants susceptible.

Sleep and arousal responses

Because virtually all SIDS cases are presumed to occur when the infant is asleep, researchers continue to study sleep patterns, how infants awaken themselves, how they continue breathing during sleep, and other aspects of sleep that may help them understand the relationship between these two phenomena. Scientists are studying the possibility that prenatal trauma, injury, or insult, such as hypoxia (a lack of oxygen reaching body tissues), may impair the function of a baby's nervous system so that the sleeping infant does not experience a normal arousal response to an episode of hypoxia or arrhythmia (irregular heartbeat). Continued studies of the central and peripheral nervous systems and normal recovery mechanisms may help clarify some of the information about these phenomena observed in earlier research.

Brainstem and nervous system

A great deal of current SIDS research is directed toward further investigation of the nervous system of SIDS infants. Scientists theorize that some babies at risk for SIDS have defects in those parts of the nervous system that control breathing and heart rate. Maturation of the brainstem may be delayed in SIDS infants. Myelin, a fatty substance that facilitates nerve signal transmission, appears to develop more slowly in SIDS victims than in nonvictims.

Metabolism

A small number of cases of sudden unexpected infant deaths appear to be related to inherited metabolic disorders. Researchers are trying to identify those disorders and determine how they interact with environmental and internal triggers to result in sudden death.

Specific neurochemicals

Other researchers are studying certain chemicals in the brain that affect the functioning of the heart, lungs, and other vital organs. For example, neurochemicals, such as adenosine, and opiates are known to affect the regulation of respiration and heart rate during times of stress.

Other Current Research Efforts

Researchers are continuing to study fetal hemoglobin levels in SIDS infants compared with non-SIDS infants. In the future, fetal hemoglobin screening may permit identification of infants at increased risk for SIDS. Other studies are focused on the possibility of increased risk for SIDS in subsequent children. The infant's body temperature; environmental factors, such as room temperature and seasonal changes; the effect of prenatal substance abuse; and child care practices also are being studied.

Other Topics of Interest

In addition to pursuing and expanding the research efforts described above, scientists continue to examine other aspects of SIDS.

Learning and behavior

Various scientists are studying the learning process of infants. In the early stages of infancy babies exhibit strong natural reflexes that are gradually replaced by learned, voluntary behaviors. It may be that babies between ages of 2 and 4 months learn how to struggle for breath when they need to. If so, this could help to explain why many SIDS deaths occur within that age range.

Home monitoring

Sometimes parents who have lost an infant to SIDS use electronic equipment to monitor the heart rate and breathing of their subsequent children. This type of monitor is designed to sound an alarm when there is an interruption of breathing or heartbeat. The decision to use a monitor should be made only after careful consideration by the parents and physician.

Sleep position

Since the late 1980's, pediatricians, physiologists, and other researchers have been reexamining the relationship of sleep position to SIDS. In the United States, the most common sleep position for infants has been on the stomach (prone). Recent studies from abroad have implicated the prone sleeping position with a greater risk of SIDS. With this evidence at hand, the American Academy of Pediatrics issued a statement on April 15, 1992, recommending that "normal infants, when being put down for sleep, be positioned on their side or back" (Pediatrics, 1992). The NICHD intends to monitor the AAP's recommendations and their impact on changes in practice with regard to infant sleep position. The NICHD is supporting critical research to investigate why the prone sleeping position may make an infant more vulnerable to SIDS.

Bedding

Investigators supported by the NICHD also have found evidence that rebreathing expired air may have contributed to the death of infants initially diagnosed as having succumbed to SIDS. These infants were found prone (face down) on pillows or cushions filled with polystyrene beads. Other types of soft bedding also may be hazardous to infants. On January 5, 1994, the Consumer Product Safety Commission issued a safety alert advising that parents not place infants to sleep on soft bedding products. The NICHD, in collaboration with the Centers for Disease Control and Prevention (CDC) and the Indian Health Service (IHS), is supporting two case control studies of medical and environmental risk factors for sudden infant death. Infant sleep practices, including the types of bedding used, are being studied in order to find out whether certain bedding practices are more frequently observed with infants who die of SIDS than with infants who do not die.

There is no question but that we all know much more about SIDS now than we did when Dr. Woolley published an article entitled "Mechanical Suffocation During Infancy: A Comment on Its Relation to the Total Problem of Sudden Death." in 1945.

We owe that further understanding to research. We anticipate that our comprehension of the subject will continue to improve as SIDS investigators around the world press on. And one day, working together, we may be able to prevent it (Valdes-Dapena, personal correspondence).

THE IMPACT OF SIDS ON PARENTS, FAMILIES, AND THE COMMUNITY

SIDS [is a] medical enigma and a social problem....social consequences of SIDS include suspicion on the part of law enforcement personnel, marital disruption, change of residence, and uncertainty with regard to future pregnancies (Peterson, in Bracken, 1984).

Any sudden, unexpected death threatens one's sense of safety and security. We are forced to confront our own mortality (Corr, 1991). This is particularly true in a sudden infant death. Quite simply, babies are not supposed to die. Because the death of an infant is a disruption of the natural order, it is especially traumatic for parents, family, and friends.

Losing a child to SIDS is a unique crisis for a family, for the child has died suddenly, unexpectedly, and for no apparent reason (DeFrain, 1991). The death of a baby from SIDS often occurs at home and the parents or caregivers are stunned to discover the lifeless infant. There is no time for them to prepare, and there is no adequate explanation for the death. In addition, the involvement of the legal system often means loss of privacy and may lead to community suspicion and rejection.

Common Grief Reactions of Parents to the Loss of a Child

Very often the loss of an infant is a couple's first encounter with death and personal loss. The first few months after a baby's birth are filled with happiness and characterized by growing psychological and biological attachments between parents and their child. Suddenly, an apparently healthy infant is dead. The death occurred after the baby was put down for sleep, usually at home--a time and place traditionally associated with security and safety. That life ended before it had really begun, and all parental expectations ended abruptly.

Bewilderment and numbness characterize early parental reactions to a child's death. Because their baby's death cannot be explained, parents often blame themselves, and they may even blame each other. They may consider themselves failures and question their ability as parents because they did not recognize any warning signs and thus did not take steps to protect their baby.

After the initial shock begins to wear off, parents may fall into a prolonged depression, may find it difficult to concentrate for any length of time, and may feel tired and irritable as a result of their sleep disruption. Parents may experience an irresistible urge to escape. Grieving parents sometimes experience muscular problems or other physical symptoms. Eating habits may become upset. Loss of appetite is common for some, while others may eat to excess.

It is normal for mothers and fathers to express their grief in different ways. For instance, women are more inclined to cry and to "talk out" their grief, while men tend to grieve in silence. Parents working outside the home may be diverted by their work, while those who stay at home are surrounded by constant reminders of their loss.

Some parents may fear for the safety of their other children and be reluctant to let them out of their sight, while others may be unable to carry on with the normal responsibilities of family life. Relatives and friends offer help and condolences, and while the help is appreciated, parents may be emotionally unable to accept those gestures of concern. At times, well-meaning people may inadvertently say the wrong things. Ignorance and misunderstandings about SIDS can complicate and aggravate the situation.

The Impact on Children in the Family

Children are affected profoundly by a death in the family, and surviving brothers and sisters tend to feel dismayed and confused about the death of their sibling. Surviving children unconsciously know that their lives will be forever shaped by that death. They may feel that they are now expected to live for two, or they build protective walls of silence around themselves. Often, surviving siblings express confusion about whether or not they are expected to acknowledge that their brother or sister ever existed (DeVita, 1993).

Surviving children may feel especially guilty about having resented all the attention lavished on the new baby. Did they somehow wish the baby's death? They may be especially troubled in the case of a SIDS death because the baby seemed healthy and normal. They may be fearful because the infant died while asleep or at rest. Could it happen to them?

Surviving children may sense that there is not enough parental attention and concern to go around, and they may try to cope on their own. Surviving siblings need to feel confident that they can express their thoughts or questions about the death as they arise. Young children may have some very frightening thoughts that they cannot express. Older children should be told as much as they are able to understand.

It is extremely important for parents to acknowledge the disruption to the family unit caused by the child's death; they need to convey to their surviving children that grief is a very human process; it is a way to live with a loss. Otherwise the mourning phase of grief may never end.

The death of a baby is like a stone cast into the stillness of a quiet pool; the concentric ripples of despair sweep out in all directions, affecting many, many people (DeFrain, 1991).

The Repercussions for Relatives and Child Care Providers

Occasionally relatives or babysitters may have been caring for the infant when the death occurred. It is not uncommon for the parents to blame the relative, the babysitter, or themselves for having left the baby. The relative or care provider should understand that the parents may not know how to talk about the death or understand the provider's sense of loss. This creates a particularly stressful situation, and counseling may be helpful for all involved. Obtaining information from professionals is important so that everyone understands the facts about SIDS and misunderstandings can be eliminated.

The Importance of a SIDS Support System

Members of support groups, counselors, medical and public health professionals, law enforcement personnel, and emergency medical responders, as well as members of the community, may suddenly become involved in the private life of a family. Their support is important during the bereavement period. At especially difficult times, it may be helpful for parents to talk with a member of a peer support group. Others who have experienced a SIDS death can help a newly bereaved parent by sharing his or her grief.

The group provides the opportunity to meet other parents who have experienced the death of an infant and who extend their friendship and understanding to newly bereaved parents. In the group setting, parents are encouraged to talk about the baby who died and express their feelings about death in a safe environment. Gradually parents begin to cope with their loss and are supported in the process (Mandell, in Culbertson, Krous, and Bendell, 1988). In addition to peer support, the family physician, minister, nurse, or counselor should be able to provide consolation and assistance.

The Community's Attitudes About SIDS

It is extremely important that members of the community understand that SIDS is an accepted and appropriate designation as an official cause of death. Parents or other caregivers are not responsible for the death and are not to be blamed. In some cases, members of the community may have viewed police involvement in a SIDS case as an indication that the death occurred under suspicious circumstances. Sometimes parents have been wrongly accused of causing the death of their baby. Unfortunately that still occurs, from time to time, today.

Many people who come into contact with the grieving family will have some role in helping them resolve their grief. The role of each will be determined by his or her relationship with the family and the stage of grief that the family is experiencing at that time.

Families will always struggle to cope with the devastating crisis precipitated by the sudden, unexpected, and inexplicable death of a baby.

The first essential in coping with a bereavement involving SIDS is to grasp the fact that one is dealing not only with a dead baby but with a damaged family (Arneil, in Schwartz, Southall, and Valdes-Dapena, 1988). Below are suggestions for members of the community to remember when they come into contact with a family that has experienced a SIDS loss:

No one can take the pain away from the grieving family.

Pain is a normal part of grieving.

SIDS parents often cry, feel ill or depressed, or have other emotional responses months or even years after the baby's death.

SIDS parents often want to talk about their baby and are pleased when others talk about the baby or take the time to listen.

SIDS parents may welcome tangible reminders of their baby.

There will always be a need for compassionate support for grieving families. For until a cause for SIDS is found, parents and families will continue to be confronted by this unpredictable--and currently still unavoidable--tragedy.

Professionals Must Work Together When a SIDS Death Occurs

Ideally each health and mental health professional who comes into contact with the families of recent SIDS victims will one day be thoroughly acquainted with the problem and prepared to conduct him/herself appropriately. One hopes that these individuals will be supportive and gentle, helpful but not overbearing, and always sensitive to the shock and grief of these relatives who, in a sense, are victims themselves (Valdes-Dapena, in Culbertson, Krous, and Bendell, 1988).

The mystery of SIDS and the consequences of such a death not only result in grief for the family but also create lingering questions, difficulties, and often a sense of confusion for the professionals who must deal with the crisis. Often responsibility for making decisions in a SIDS or other infant death does not lie with a single agency.

At times professionals appear to act at odds with each other because of their differing roles in relation to such infant deaths. For example, the implementation of investigative procedures and law enforcement policies may seem insensitive to those who conduct bereavement support and counseling services.

Professionals should realize that the family and the community are best served by agreement regarding common goals and by the establishment of strong professional partnerships through education and communication. Interagency communication and cooperation are critical so that appropriate support services can be provided and, at the same time, investigative procedures are completed.

Developing the best possible professional and community services requires fostering open communication; respecting and understanding various professional and community roles and levels of expertise; and working together to formulate policies and procedures with common goals in mind.

When the above requirements are met, the response to a SIDS death, or any unexplained infant death, can be provided in a truly professional manner so that the parents and families who suffer these losses are not subjected to the contradictions and vagaries of various agencies, causing a painful situation to become intolerable.

NSIDRC is sponsored by the Maternal and Child Health Bureau, Health Resources and Services Administration, U.S. Department of Health and Human Services. NSIDRC is operated by Circle Solutions, Inc.

Publication No. 87-2905. Peterson, D.R. "Sudden Infant Death Syndrome." In: Bracken, M.B. (Ed.), Perinatal