Sudden infant death syndrome: How much mothers and health professionals know

Background: Behavioral risk factors are associated with sudden infant death syndrome (SIDS). Education about the risk factors of SIDS is important for prevention. Our aim was to determine the knowledge and attitude of parents and health professionals about SIDS. Methods: A total of 174 health professionals and 150 mothers were enrolled in this study. Mothers' data were collected by telephone interview and health‐care professionals were interviewed by the same investigator. Results: Only 39% of mothers were aware of SIDS. Forty‐six percent of the mothers preferred a supine sleeping position for their infant and 16% of the parents were bed‐sharing with their infants. Seventy‐three percent of health professionals selected side, 17% supine and 10% prone sleeping position as the safest sleeping position. Frequencies for awareness of risk factors were: bed‐sharing (75%), soft bedding (70%), pillow use (52%), toys in bed (90%), high room temperature (67%) and smoking (88%). Total knowledge score of health professionals who selected supine sleeping position as the safest was significantly higher (P < 0.001). Conclusion: Most of the mothers were unaware of SIDS and less than half preferred a supine sleeping position for their infant. Only 72% of health professionals recommended a certain sleeping position during family interviews. Health professionals are more often recommending the side sleeping position or prone. Education of families and health professionals for the risk factors of SIDS may reduce the number of deaths from SIDS in Istanbul.     

Sleeping position and sudden infant death syndrome (SIDS): effect of an intervention programme to avoid prone sleeping

The proportion of prone sleeping among sudden infant death syndrome (SIDS) victims and infants in general, and the rate of SIDS were prospectively studied in the county of Hordaland, Norway, three years before (1987–89) and three years after (1990–92) a campaign to discourage prone sleeping. Before the campaign, 64% of random reference infants were put prone versus 8% after (p < 0.0001). Concurrently, the rate of SIDS decreased from 3.5 to 1.6 per 1000 live births (63 infants before and 30 after the campaign, p = 0.0002). Prone sleeping was not considered a statistically significant risk factor for SIDS before (OR 2.0,95% CI 0.8–4.5), but was highly significant (OR 11.3,95% CI 3.6–36.5) after the campaign. Prone sleeping is an important risk factor for SIDS, but the association may be missed in epidemiological studies if prone is the predominant sleeping position. Behaviour with regard to sleeping position may be changed rapidly by means of a simple campaign.     

Carbon dioxide concentrations in the environment of sleeping infants

Abstract In 22 infants continuous measurements were made of the concentration of carbon dioxide (CO₂) in inspired air during sleep. Evidence was found of CO₂ enrichment of inspired air in certain environmental conditions. The levels achieved were not sufficiently high to acutely endanger an infant. Carbon dioxide concentrations as high as 2-3% were observed in the prone position when the infant's head was under a blanket and when the lower face was obscured by bedding. Sleeping prone on a sheepskin also resulted in an increased concentration of CO₂ but to a lesser extent than being under a blanket. In awake infants the presence of a pacifier also promoted an excess of CO₂ in the inspired air, both in the prone and supine positions. The physiological and clinical implications of these findings, in relation to the Sudden Infant Death Syndrome (SIDS), are unknown and warrant investigation.     

Prematurity,sleeping position and sudden infant death syndrome

Preterm birth and prone sleeping position significantly increase the risk of sudden infant death syndrome (SIDS). The reduced incidence of SIDS with supine sleeping has been well publicised, yet some prematurely born infants are slept prone at the high-risk age for SIDS. This may reflect inadequate educational targeting of high-risk groups and/or concerns about possible adverse effects of supine sleeping. In addition, parents may receive mixed messages about sleeping positions, as they witness their prematurely born infants being nursed prone on neonatal units, often for many weeks. In the neonatal period, the prone position improves oxygenation, tidal volume and compliance of preterm infants with respiratory distress. The limited data available suggest prone positioning is also beneficial for convalescent, preterm infants. Thus, it is not clear when the advantages of prone sleeping cease. Studies are required to determine when supine sleeping for prematurely born infants can safely be recommended and hence an unambiguous message given to parents.     

Changing infants' sleep position increases risk of sudden infant death syndrome. New Zealand Cot Death Study.

OBJECTIVE: To examine whether the prone sleeping position may increase the risk for sudden infant death syndrome (SIDS), particularly in infants unused to prone sleep. DESIGN: A 3-year (1987-1990) case-control study. SETTING: Nationwide study in New Zealand. SUBJECTS: Four hundred eighty-five infants who died of SIDS and 1800 controls. MAIN OUTCOME MEASURES: Infants were classified as unaccustomed to prone if their usual sleep position was nonprone and they were placed prone for the last sleep. Secondary prone was used to describe infants placed nonprone but found prone. RESULTS: Infants usually and last placed nonprone were at the lowest risk for SIDS (odds ratio [OR], 1.0); those usually and last placed prone were at increased risk (adjusted OR, 4.6; 95% confidence interval, 3.4-6.3). Risk was greatly increased among infants unaccustomed to the prone position (adjusted OR, 19.3; 95% confidence interval, 8.2-44.8). These infants accounted for 8% (31/ 386) of all SIDS deaths. Ninety percent (28/ 31) of infants in this group were found prone, and 71% (20/28) of those found prone were found with their faces turned down into bedding-a position in which asphyxia has been implicated as a mechanism of death. In addition, 138 infants who died of SIDS were last placed nonprone. Forty-seven infants (34%) in this group were found prone (secondary prone), and 60% (28/47) of those found prone were found with their faces turned down into the bedding. This group accounted for 12% of all SIDS deaths. Most of these infants (91% [43/47]) were usually placed nonprone. CONCLUSIONS: Infants placed supine to sleep were at the lowest risk of SIDS, which supports the recommendation that this is the preferred sleeping position for healthy infants. In New Zealand, 20% of SIDS deaths involved lack of experience with the prone sleeping position. Our findings suggest the possibility that an infant's competence in escaping from potentially lethal situations during prone sleep (eg, the face-down position) may be impaired by inexperience in prone sleeping. Great caution should be exercised in placing infants unaccustomed to the prone sleeping position in the prone position.     

SIDS risk factors and factors associated with prone sleeping in Sweden.

OBJECTIVE: To compare the current prevalence of risk factors for sudden infant death syndrome (SIDS) in Sweden with a decade earlier, and assess factors associated with prone sleeping. METHODS: The results of a cohort study (Infants of Western Sweden) and a population based case-control study (Nordic Epidemiological SIDS Study) were examined. Subjects were 5600 healthy 6 month old infants born in 2003 in the Western Sweden region and 430 healthy Swedish infants born between 1991 and 1995. RESULTS: Prone sleeping decreased from 31.8% to 5.6% and supine sleeping increased from 35.3% to 47.3%. Side or side/supine sleeping increased from 25.2% to 43.8%. Maternal smoking during pregnancy decreased from 23.5% to 9.5%. The risk for prone sleeping increased if the mother was unemployed (OR 2.4, 95% CI 1.5 to 4.0), if she was a heavy smoker in the third trimester (OR 44.1, 95% CI 1.6 to 1199.6), and if the child was irritable (OR 2.5, 95% CI 1.3 to 5.1), shared a bedroom with siblings (OR 2.6, 95% CI 1.0 to 6.6), or never used a dummy (OR 3.2, 95% CI 1.9 to 5.4). CONCLUSIONS: Parents have complied with advice to prevent SIDS given at infant welfare centres for the last 10 years. A change in the preferred sleeping position from side variants to exclusively supine, and reducing the number of pregnant women smoking may be beneficial. Use of a prone sleeping position was associated with maternal employment status, maternal smoking, temperament of the child, dummy use, and sharing a bedroom with siblings.     

Effects of body position on sleep and arousal characteristics in infants

The prone sleeping position has been identified in world-wide epidemiological studies as a major risk factor for sudden infant death syndrome (SIDS). Public awareness campaigns throughout the western world have led to an over 50% reduction in postneonatal mortality and frequency of SIDS. This reduction in mortality has been mainly attributed to the avoidance of the prone sleep position. Various mechanisms have been postulated to explain the increased risk of SIDS associated with prone sleeping, among these, impairment of arousal from sleep. This paper reviews the effects of prone sleeping on infant sleep architecture, arousability from sleep and cardiorespiratory controls.Sleeping in the prone position has been shown to increase the amount of time spent sleeping, particularly time spent in quiet sleep (QS). Sleeping prone has also been demonstrated to be associated with a reduced responsiveness to a variety of arousal stimuli. Such impairment of arousal has been demonstrated to be associated with changes in control of autonomic cardiac function.During arousal, heart rate, blood pressure and breathing movements increase, while gross body movements occur to avoid the stimulus. Any impairment in arousability from sleep such as could occur when infants sleep in the prone position, could possibly contribute to the final pathway to SIDS.     

Stop SIDS--sleeping solitary supine, sucking soother, stopping smoking substitutes

The recognition of prone sleeping and maternal smoking as modifiable risk factors for sudden infant death syndrome (SIDS), has drastically decreased SIDS incidence. However, during the last years other factors have become necessary to consider to further reduce the risk of SIDS. Side sleeping implies a greater risk than supine sleeping but is still common. Bed sharing may increase the risk of SIDS, while use of a pacifier seems to be protective. Replacement of maternal smoking with nicotine substitutes is not harmless.

Conclusion: To further reduce the risk of SIDS, exclusive supine sleeping should be encouraged and side sleeping discouraged. When the breast-feeding is established, a pacifier can very well be used at bedtime. Bed sharing can increase the risk of SIDS if the infant is below 2-3 months of age, especially if the mother is a smoker. Any nicotine use should be avoided during pregnancy and breast-feeding.     

The healthy human infant tends to sleep in the prone rather than the supine position

There are few reports about developmental behavior relating to roll over among healthy infants. We assessed the relationship between the placed position on sleeping and altered sleeping position the next morning by roll over among healthy infants. A health check-up clinic distributed a total of 1626 questionnaires to parents whose infant's ages are 1.5 years (or 18 months) old. The age at the first roll over and the change in sleeping position the next morning after they started to roll over, were investigated. The mean age of roll over from the supine to the prone among infants who were placed mainly in the prone sleeping position, at least in the first week of life, was 4.0 months (S.D., 1.1). The mean age of roll over from the supine to the prone among infants who were placed mainly in the supine sleeping position during early neonatal life and thereafter was 4.4 months (S.D., 1.2). The age of the first roll over from supine to prone was significantly younger in infants who were placed mainly in the prone sleeping position during early neonatal life. Among 651 infants who had been placed supine, 34.7% were found prone by roll over the next morning. Among 211 infants who had been placed prone, 14.2% were found supine by roll over the next morning. The number of infants who rolled over from supine to prone position was statistically greater than those from prone to supine. It is likely that the healthy human infant tends to sleep in the prone rather than the supine position. The finding is especially important for the correct assessment of the position in which SIDS cases were found dead.     

Determinants of infant sleep position in an urban population

The incidence of SIDS has decreased by 40% since the Back to Sleep campaign was initiated. However, the rate of SIDS in the District of Columbia continues to be approximately double the national rate. The purpose of this study was to determine the prevalence and determinants of prone sleeping among infants in the District of Columbia and to ascertain what information is being provided to parents by health care professionals by a cross-sectional survey of parents of infants 0-6 months of age presenting for well child care at Children's Health Center, Children's National Medical Center, in Washington, DC. We recruited a consecutive sample of 126 parent-infant pairs, of which 92.9% were African-American. The average infant was 73 days old, was 3,003 grams at birth, and was full term. When asked how the infants were placed for sleep the night before the interview, 34.1 % of parents had placed the infant supine, 50.8% side, and 15.1% prone. Nearly half (48%) of infants slept in an adult bed with the mother. More than one third of the infants had been placed prone for sleep at least once since hospital discharge. Most common reasons for sleeping supine included SIDS risk reduction or health care professional advice. Side sleepers did so primarily because of concern about vomiting, health care provider advice, or SIDS. Infants were placed prone primarily because the infant slept better. When asked about information received from a health care provider, 70.6% of parents stated that they had received information about sleep position and 64.3% about the hazards of passive smoking. Eight parents observed nursery personnel placing their infants prone. Only 16.7% of the total study population had received a Back to Sleep brochure, read it, and recalled that it recommended back sleeping. Infants were more likely to sleep prone if there was a grandparent in the home (OR 2.9, p<0.05) or if they were the firstborn (OR 2.17, p<0.05). Infants were more likely to sleep supine if parents had heard a back recommendation from a health care professional (OR 5.7, p<0.001). Infants were least likely to sleep supine if the parents had heard a side or a side/back recommendation (OR 0.26, p=0.001). Infant sleep position was not ter, reading the Back to Sleep brochure. In conclusion, more than one third (35.7%) of infants in this predominantly African-American population have been placed prone for sleep at least once; 15% slept prone the night before the interview. Almost one third of parents received no information about sleep position, but parents receiving a verbal supine recommendation were most likely to place their infant supine. Receiving written information did not affect sleep position. Improved educational efforts for parents of African-American newborns should continue to focus on encouraging supine positioning, smoke cessation, and other safe sleep practices.     

Why is there an increased risk for sudden infant death in prone sleeping? Fear paralysis and atrial stretch reflexes implicated?

Kaada B. Why is there an increased risk for sudden infant death in prone sleeping? Fear paralysis and atrial stretch reflexes implicated. Acta Prediatr 1994;83:548–57. Stockholm. ISSN 0803–5253 A number or recent reports have indicated a higher risk of sudden infant death syndrome (SIDS) in the prone sleeping position, compared with the supine position. However, the biological mechanisms for this increased risk have not been established. For this report, two biological explanations are proposed, each of which may be influenced by altered sleeping position in such a way that they may create conditions for increased triggering of SIDS.     

Reduced arousals following obstructive apneas in infants sleeping prone

A decreased arousability and an increased risk for sudden infant death syndrome (SIDS) have been shown in infants sleeping prone. Obstructive apnea, a known risk factor for SIDS, is less often terminated by an arousal reaction in infants than in adults. The effect of body position on the arousal reaction to spontaneous respiratory events had not been previously studied in infants. The aim of our study was to see if body position has an influence on the frequency and delay of the arousal reaction to obstructive apnea. All obstructive events recorded during two successive nights in 20 infants sleeping one night prone and one night supine were studied. During the supine recording 153 obstructive events were detected, and 217 were detected during the prone session. Prone sleep was not associated with an increased frequency of obstructive apneas. Total sleep time was 382 min (range, 283-456) supine and 423 min (range, 325-521) prone (p = 0.003). Obstructive events duration was 6.5 s (range, 3-21.5) when sleeping supine and 8 s (range, 3.5-30.5) when prone (p = 0.002). Behavioral arousal were found in 57.5 % of obstructive events recorded supine and in 31.3 % of those seen prone (p < 0.001). Arousal occurred after 8 s (range, 0-21) from the start of the obstructions when supine and 10.5 s (range, 3.5-23.5) when prone (p = 0.001). Sighs were found in 34 % of supine obstructive events and in 44.7 % of those prone (p = 0.040). A reaction, i.e. arousal or sigh, was found in 91.5 % of supine events and 76 % of those prone (p < 0.001). We conclude that when sleeping supine, infants arouse to obstructive events more often and after shorter delay than when prone.     

Circadian variations in sudden infant death syndrome: associations with maternal smoking, sleeping position and infections. The Nordic Epidemiological SIDS Study

AIM: To study circadian variation in the sudden infant death syndrome (SIDS) and possible associations with risk factors for SIDS. METHODS: A questionnaire-based case-control study matched for place of birth, age and gender was conducted in Denmark, Norway and Sweden: The Nordic Epidemiological SIDS Study. The study comprised 244 SIDS victims and 869 control infants between September 1992 and August 1995. The main outcome was hour found dead. RESULTS: A significant circadian pattern was observed among the 242 SIDS victims with a known hour found dead, with a peak at 08.00-08.59 in the morning (n = 33). Of the SIDS victims, 12% were found dead at 00.00-05.59, 58% at 06.00-11.59, 21% at 12.00-17.59 and 9.0% at 18.00-23.59. When comparing night/morning SIDS and day/evening SIDS (found dead 00.00-11.59 and 12.00-23.59, respectively), the proportion of night/morning SIDS was high among infants of smoking mothers (81% vs 53%, p < 0.001), infants with a reported cold (82% vs 64%, p = 0.007) and infants sleeping side/supine (81% vs 60%, p < 0.001). No associations were observed between hour found dead and other sociodemographic risk factors for SIDS. Risk (odds ratio and 95% confidence interval) of night/morning SIDS and day/evening SIDS was 7.0 (4.5-10.9) and 1.5 (0.8-2.5), respectively, for maternal smoking, 2.2 (1.5-3.1) and 0.6 (0.3-1.3), respectively, if the infant had a reported cold, 3.7 (2.1-6.6) and 3.1 (1.1-8.4), respectively, if the infant was put to sleep in the side position (supine reference), and 11.0 (5.9-20.2) and 21.6 (7.6-60.8), respectively, if the infant was put to sleep in the prone position. CONCLUSION: The observed higher proportion of night/morning cases in SIDS if the mother smoked, if the infant was reported to have a cold and if the infant was sleeping side/supine may contribute to the understanding of some epidemiological characteristics of SIDS.     

Epidemiology of sudden infant death syndrome in Japan

An epidemiological survey was carried out to examine the present situation with respect to sudden infant death syndrome (SIDS) in Kanagawa Prefecture. Questionnaires on sudden unexpected death of infants aged < 1 year in 1990-91 were sent to the hospitals and clinics in Kanagawa Prefecture which may take care of such infants. By analysing information from 10 485 replies, 48 out of 73 reported sudden infant deaths were confirmed to be SIDS, although autopsy was not performed in 13 cases (27%). The incidence of SIDS per 1000 live births in Kanagawa Prefecture was 0.29 in 1990 and 0.31 in 1991; and if limited to autopsy cases 0.19 and 0.25, respectively. Sudden infant death syndrome cases in Japan were found to occur more frequently when infants were < 6 months old, at home and sleeping alone, but less in the winter and between midnight and early morning. There was little difference between the numbers in prone and supine sleeping positions at discovery. It was not clear whether SIDS occurred more often to babies sleeping prone than supine, because there were no controls matched with the SIDS cases. In future, continuous epidemiological surveys of SIDS in Japan should be carried out.     

Survey of sleeping position recommendations for prematurely born infants on neonatal intensive care unit discharge

Introduction Prematurely born infants are at an increased risk of sudden infant death syndrome (SIDS), particularly when sleeping prone. Parents are strongly influenced in their choice of sleeping position for their infant by practitioners. The aim of this study was to determine the neonatal units’ recommendations regarding the sleeping position for premature infants prior to and after discharge and ascertain whether there had been changes from those recorded in a survey performed in 2001–2002. Materials and methods A questionnaire survey was sent to all 229 neonatal units in the United Kingdom; 80% responded. Results and discussion The majority (83%) of units utilized the supine sleep position for infants at least 1–2 weeks prior to discharge, but after discharge, only 38% of the units actively discouraged prone sleeping and 17% additionally recommended side sleeping. Compared to the previous survey, significantly more units started infants with supine sleeping 1–2 weeks prior to discharge (p < 0.0001) and fewer recommended side sleeping after discharge (p = 0.0015). However, disappointingly, less actively discouraged prone sleeping after discharge (p = 0.0001). Conclusion Recommendations regarding sleeping position for prematurely born infants after neonatal discharge by some practitioners remain inappropriate. Evidence-based guidelines are required as these would hopefully inform all neonatal units’ recommendations.     

Physician beliefs and practices regarding SIDS and SIDS risk reduction

The AAP has alerted pediatricians to the importance of safe sleep environment for infants. The elements of a safe sleep environment include supine sleep position, safe crib, and avoidance of smoke exposure, soft bedding, and overheating. With the Back to Sleep campaign, prone sleeping among all U.S. infants has decreased to less than 20%, and the incidence of SIDS has decreased 40%. However, the decline in SIDS and prone sleeping has leveled off in recent years. Further declines may be possible with decreasing other modifiable risk factors, such as prenatal and postnatal exposure to cigarette smoking. Prior studies have demonstrated that health care professional advice is influential in determining infant care practices. It is important that physicians caring for infants be aware of the importance of a safe sleep environment and understand other modifiable risk factors for SIDS. We surveyed a random sample of 3,717 physicians in North Carolina and the metropolitan Washington, DC, area to determine knowledge, beliefs, and practices regarding SIDS and SIDS risk reduction among physicians caring for pregnant women and infants. Twenty-three percent (835) responded. Most physicians are aware of prone sleeping and cigarette smoke exposure as risk factors for SIDS. Almost all physicians agree that there are measures that can be taken to reduce the risk of SIDS, and they consider it important to discuss SIDS and SIDS risk reduction strategies with parents of young infants. In spite of this belief, only 56% of family/general practitioners, 18% of obstetrician-gynecologists, and 79% of pediatricians discuss SIDS routinely. Only 35% of pediatricians, 15% of family/general practitioners, and 16% of obstetrician-gynecologists provide written information. In addition, only 38% of physicians recommend supine, while 50% recommend side or back, 6% side, and 7% prone. Only two thirds of pediatricians and one third of family/general practitioners are aware that the AAP recommends supine as the preferred sleep position for infants. Pediatricians are more likely to be aware of the AAP recommendation (p<0.0001) and to discuss SIDS risk reduction strategies with parents (p=0.03). We conclude that many physicians who care for infants are unaware of the AAP's most current recommendation for sleep position and are incorrectly recommending the side position. Physicians may also be unaware of other sleep environment hazards. Further educational efforts must continue for physicians who provide care to pregnant women and children to ensure a continued decline in the incidence of SIDS.     

A 3-year longitudinal analysis of changes in fitness, physical activity, fatness and screen time

Aim:  To analyse whether changes in physical activity index (PAI), screen time (ST: television, computer) and body mass index (BMI) made a contribution to longitudinal changes in fitness of children and adolescents. Additionally, we analysed the interaction between baseline fitness level and changes in fitness.
Methods:  This is a 3-year longitudinal study of 345 high school students aged 11–19 years. Students performed curl-ups, push-ups and 20-m shuttle run tests from Fitnessgram. PA and ST were evaluated using a standard questionnaire. Standardized scores of fitness tests were summed. Changes over time were calculated as Δ₁ (2007 minus 2006), Δ₂ (2008 minus 2007) and Δ₃ (2008 minus 2006).
Results:  Changes in PAI were positively and independently associated with changes in fitness in Δ₁, Δ₂ and Δ₃. Changes in BMI were negatively associated with changes in fitness in Δ₃. Participants highly fit at baseline were those who showed positive changes in PAI over Δ₃, decreased changes in ST and had the lowest increase in BMI over 3 years compared with those low-fit at baseline.
Conclusions:  Changes in BMI were associated with changes in fitness over 3 years. However, changes in PAI were the best predictor for changes in fitness in each year and over the 3 years of evaluation in youth.     

Risk factors for sudden infant death syndrome following the prevention campaign in New Zealand: a prospective study

OBJECTIVES: To identify the risk factors for sudden infant death syndrome (SIDS) following a national campaign to prevent SIDS. METHODS: For 2 years (October 1, 1991 through September 30, 1993) data were collected by community child health nurses on all infants born in New Zealand at initial contact and at 2 months. RESULTS: There were 232 SIDS cases in the postneonatal age group (2.0/1000 live births) and these were compared with 1200 randomly selected control subjects. Information was available for 127 cases (54.7%) and 922 (76.8%) of controls. The previously identified modifiable risk factors were examined. The prevalence of prone sleeping position of the infant was very low (0.7% at initial contact and 3. 0% at 2 months), but was still associated with an increased risk of SIDS. In addition, the side sleeping position was also found to have an increased risk of SIDS compared with the supine sleeping position (at 2 months: adjusted odds ratio (OR) = 6.57; 95% confidence interval (CI) = 1.71, 25.23). Maternal smoking was found to be the major risk factor for SIDS. Bed sharing was also associated with an increased risk of SIDS. There was an interaction between maternal smoking and bed sharing on the risk of SIDS. Compared with infants not exposed to either bed sharing or maternal smoking, the adjusted OR for infants of mothers who smoked was 5.01 (95% CI = 2.01, 12.46) for bed sharing at the initial contact and 5.02 (95% CI = 1.05, 24. 05) for bed sharing at 2 months. In this study breastfeeding was not associated with a statistically significant reduction in the risk of SIDS. The other risk factors for SIDS identified were: unmarried mother, leaving school at a younger age, young mother, greater number of previous pregnancies, late attendance for antenatal care, smoking in pregnancy, male infant, Maori ethnicity, low birth weight, and shorter gestation. CONCLUSIONS: After adjustment for potential confounders, prone and side sleeping positions, maternal smoking, and the joint exposure to bed sharing and maternal smoking were associated with statistically significant increased risk of SIDS. A change from the side to the supine sleeping position could result in a substantial reduction in SIDS. Maternal smoking is common in New Zealand and with the reduction in the prevalence of prone sleeping position is now the major risk factor in this country. However, smoking behavior has been difficult to change. Bed sharing is also a major factor but appears only to be a risk to infants of mothers who smoke. Addressing bed sharing among mothers who smoke could reduce SIDS by at least one third. Breastfeeding did not appear to offer a statistically significant reduction in SIDS risk after adjustment of potential confounders, but as breastfeeding rates are comparatively good in New Zealand, this result should be interpreted with caution as the power of this study to detect a benefit is small.     

Sleeping position and sudden infant death syndrome in Norway 1967-91.

OBJECTIVE--To investigate, in a population based national study, the association between sleeping position of infants and the occurrence of sudden infant death syndrome (SIDS). DESIGN--A retrospective survey and registry based ecological study. A questionnaire based surveillance of sleeping position was obtained in a random sample (n = 34,799) and surveillance of SIDS was based on all infants born in Norway 1967-91, surviving the perinatal period. Variables studied from the questionnaire were usual sleeping position (placed), breast feeding at 3 months, and maternal smoking in pregnancy, and from the Medical Birth Registry maternal age, birth order, and birth weight. RESULTS--Proportion of infants sleeping prone increased from 1970 (7.4%) to 1989 (49.1%) and dropped in 1990 (26.8%) and 1991 (28.3%). Occurrence of SIDS increased from 1970 (1.1/1000) to 1989 (2.0) before dropping in 1990 and 1991 (1.1). IMPLICATION AND RELEVANCE OF RESULTS--A cause effect relationship between prone sleeping and SIDS as suggested in previous studies is supported by the present; and so far only, national study of infants'' sleeping position.