S. M. Beal

An overview of retrospective case-control studies investigating the relationship between prone sleeping position and SIDS

A critical overview of 19 case‐control studies that have investigated the relationship between prone sleeping position and sudden infant death syndrome (SIDS) is presented. Issues relating to the non‐comparability of the studies are described in terms of: (i) case definition; (ii) selection of controls; (iii) quality of the sleeping position data; (iv) recall bias; and (v) adjustment for confounding factors. All studies showed a positive association (2 out of the 19 studies were not significant) between prone sleeping position and SIDS. Meta‐analysis techniques applied to six of these studies, based on ‘usual’ sleeping position in cases and population representative controls, has confirmed an overall higher risk of SIDS in infants who usually sleep prone. The most common odds ratio for an association between prone sleeping position and SIDS was 2.72 (95% confidence interval 2.27‐3.26). The extent to which the methodological problems of retrospective case‐control studies interfere with our interpretations of this association are discussed.

Potentially dangerous sleeping environments and accidental asphyxia in infancy and early childhood.

Infants and young children may be exposed to a variety of dangerous situations when left sleeping in cots, chairs, or beds. A review of 30 cases of accidental asphyxia occurring in infants and young children who had been left to sleep unattended was undertaken from the necropsy and consultation files of the Adelaide Childrens Hospital. Causes of death included hanging from loose restrainers, clothing, or a curtain cord (12 cases), positional asphyxia/wedging from slipping between a mattress and bed/cot sides or wall, or from moving into a position where the face was covered and the upper airway occluded (16 cases), and suffocation from plastic bed covers (two cases). Cases of co-sleeping in bed with an adult and of non-accidental asphyxia were not included in this review. As the pathological findings were on occasion identical to those that are typically found in sudden infant death syndrome, adequate death scene examination was vital in several cases to allow identification of lethal sleeping environments and to enable steps to be taken to minimise the risk of future deaths due to similar situations. For example, two cases in which infants asphyxiated in rocking cradles led to the investigation of the cradles and to formulation of specific safety recommendations regarding the angle of tilt. Two infants who died after becoming wedged between the back of a couch and a co-sleeping parent in one case and cushions in the other, would indicate that this also represents a potentially lethal sleeping position. Other dangerous situations involved infant car seat restraints, seats with loose harnesses, cots with movable sides or projecting pieces, thin plastic mattress/pillow coverings, and beds with spaces between the mattress and cot side or wall. Lack of supervision at the time of death was a feature of each case.

Recurrence incidence of sudden infant death syndrome.

The incidence of sudden infant death syndrome (SIDS) between birth and 2 years of age in South Australia was found to be 2.1/1000 live births. The incidence in previous siblings was 10 times that expected, in second degree relatives five times, and in third degree relatives four times that expected for the community. The minimum incidence in the next subsequent sibling was five times that expected. Except for one family in which both twins died during the same night, the surviving twin has never died (23 infants). The incidence of SIDS in adopted infants was similar to the incidence in natural born infants. Families in which two or more siblings died from SIDS differed from families in which only one infant died from SIDS in several ways. More infants were over 12 months old, and the mothers had an increased incidence of previous miscarriage and threatened miscarriage during the pregnancy with the infant who died. In one family both infants had bronchomalacia, and two families were severely socially deprived. For most families (92%) in which an infant died from SIDS the risk of recurrence is small (less that twice the expected risk). We have identified a small subgroup (8%) with a significantly increased risk of recurrence.

Accidental death or sudden infant death syndrome

Objective: To describe the reasons why it is difficult to decide whether to attribute some infant deaths to accidents or to SIDS.

Specific dangers associated with infants sleeping on sofas

Aim: A study was undertaken to examine specific circumstances that may lead to accidental asphyxial deaths in infants on sofas.

Gastric aspiration and sleeping position in infancy and early childhood

Abstract: Concern has been expressed that the recommendation of supine sleeping position for infants would result in an increase in deaths due to gastric aspiration. A review of 196 cases of infant and early childhood death in children under 3 years of age, occurring over a 9‐year period (September 1989 to August 1998) was undertaken to ascertain how many cases of significant gastric aspiration had occurred. Extensive and widespread filling of the airways/alveoli with gastric contents was found in three infants/young children aged 5, 6 and 30 months, respectively. In each instance the body had been found lying face down (prone), with the face in a pool of vomitus in at least one case. No cases of significant gastric aspiration were found in infants who had been found lying on their sides or backs (supine). In addition, no significant increase in numbers of infant and early childhood deaths in South Australia due to gastic aspiration over this time could be demonstrated. Concerns that the supine rather than the prone position is more likely to result in significant gastric aspiration are not supported by this study.

Has changing diagnostic preference been responsible for the recent fall in incidence of sudden infant death syndrome in South Australia

Objective: An apparent decrease in deaths attributed to sudden infant death syndrome (SIDS) has been noted in a number of diverse geographical areas during the past several years. At the same time the definition of SIDS has been in a state of flux and some observers have raised the possibility that the fall in SIDS deaths is due to diagnostic transfer rather than to a genuine decrease in numbers. The present study was undertaken to investigate this possibility.

Munchausen syndrome by proxy: repetitive infantile apnoea and homicide.

Munchausen syndrome by proxy, or simply Munchausen by proxy, was first described in 1977 by Meadow as a condition in which a parent or caretaker deliberately simulates or creates disease in a child in order to attract the attention of the medical profession.’ Since the original description in the literature there have been increasing numbers of patients reported from a variety of countries,2 and it now seems that many paediatric hospital physicians have experience or knowledge of a case. Given the significant morbidity, mortality, and diagnostic difficulties associated with this syndrome, with thought it appropriate to review the characteristic features of these cases, and in particular those that present with repetitive apnoeic episodes. Asher, in 1951, was the first person to use the term ‘Munchausen’ in the medical literature3 when he described a syndrome in which patients travelled from hospital to hospital obtaining admission (and often treatment) by fabricating symptoms, signs and medical histories. The syndrome is named after Baron von Munchausen, an eighteenth century German soldier who was known for his exaggerated stories. Unfortunately the complex and contrived stories that are fabricated by patients suffering from Munchausen syndrome result in wastage of medical resources with a great number of unnecessary tests, investigations and hospital admissions. Equally unfortunate are the number of unnecessary surgical treatments resulting in considerable patient morbidity. Features of this syndrome have been reviewed recently by Parker and Barrett! There is a connection between Munchausen syndrome and Munchausen by proxy, in that a high percentage of parents involved in the perpetration of Munchausen by proxy have had histories of factitious i l l n e ~ s . ~ It is, however, vital to separate clearly the two entities, as Munchausen by proxy involves the deliberate harming of a child, with a reported mortality rate of 33% in one series of infants with induced recurrent apnoeic episodes.6 The mortality rate in siblings in the same series was even higher at 55%. This contrasts with Munchausen syndrome,

V-shaped pillows and unsafe infant sleeping

To investigate the possibility that adult size V‐shaped pillows may be associated with accidental asphyxial deaths in infants.

Sudden infant death syndrome in South Australia 1968-97. Part I: changes over time.

Objective: To compare the epidemiology of sudden infant death syndrome (SIDS) over three consecutive decades.