Sudden unexplained collapse within the first 12 h of life is a rare but recognised event. Over a 2-year period, five infants, previously assessed as healthy, were found collapsed in our maternity unit in the care of their primiparous mothers. Two were found prone on their mother’s chest, and two were in their mother’s bed. The outcomes were poor, with four neonatal deaths and one death at 18 months. The rate of sudden unexplained neonatal collapse was 0.4 per 1000 live births. No cause for collapse was identified despite extensive investigations, which included postmortem in all the neonatal deaths. One infant, however, showed widespread antenatal brain damage at postmortem. It is postulated that some infants with an underlying vulnerability may maladapt to extrauterine life following an hypoxic stressor possibly caused by positional airway obstruction.
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Sudden collapse of apparently well term infants within hours of birth is a recognised event. In many, an underlying cause will be found, but a few remain unexplained.1 Following a cluster of cases in our hospital, we undertook a review of such cases with a view to identifying common features and relative frequency.
We identified and reviewed the records of inborn infants >36 weeks gestation who were apparently well at birth but were admitted to our neonatal unit (from labour or postnatal wards) following sudden cardiorespiratory collapse within the first 12 h, in the 2-year period from 1 December 2004 to 30 November 2006. Collapse secondary to congenital abnormality, infection or metabolic disease was excluded.
There were 12 362 live births in this period. Five infants in the care of their mothers collapsed within 12 h having been assessed as well after birth. No cases met the exclusion criteria. Details of the mothers and infants are summarised in tables 1, 2, and the circumstances surrounding the collapses are detailed below. Following collapse, all infants received cardiopulmonary resuscitation and intensive care. All developed multiorgan failure including severe encephalopathy, and care was reorientated to palliation. In no case was a cause found for collapse, despite full investigation. Four infants died shortly afterwards; Case 4 survived with spastic quadriplegia, visual and hearing impairment, and died aged 18 months of septicaemia.
Case 1: A male infant was left unattended with his mother to establish breast feeding. At 2 h 9 min, his father found him cyanosed on the bed, supine next to his sleeping mother. He died at 25 h of age. A postmortem revealed widespread gliosis and micromineralisation of the brain, representing extensive brain injury of several days predating labour and delivery. No other cause for collapse was found.
Case 2: A male infant was placed prone onto his mother’s abdomen for skin-to-skin contact after birth. At 1 h 5 min, he was found collapsed in the same position while his mother was in the lithotomy position, having her episiotomy sutured. Her pain was being managed with an epidural and local anaesthetic. He died aged 79 h. Postmortem findings were consistent with severe hypoxic-ischaemia at the time of collapse. In addition, the thymus was small, compatible with considerable period of prolonged antemortem stress.
Case 3: A female infant was placed skin to skin on her mother to establish breast feeding. At 1 h and 42 min while having an episiotomy repaired under local anaesthetic and entonox, her mother became concerned about the well-being of her infant, who had appeared to have slipped beneath the breast. A midwife attended and found her floppy, apnoeic and bradycardic. The infant survived. An MRI scan at 3 months showed cerebral atrophy with loss of white-matter volume, enlarged ventricles and a thin cortex. She developed spastic quadriplegia, blindness, deafness and seizures before her death aged 18 months. A postmortem was not performed.
Two further term infants were born to primigravid mothers following an unremarkable pregnancy and delivery with optimal 5 min Apgar scores. They were found collapsed at 36 min and 8 h of age respectively, one in the mother’s arms and the other lying in a lateral position on the mother’s bed. At presentation, they were both severely acidotic and required full resuscitation and intensive care. Both infants died in the following 4 days from severe encephalopathy and multiorgan failure. Each had a postmortem which was consistent with severe hypoxic damage occurring around the time of collapse or birth. No cause for collapse was found in either case. Neither set of parents was able to be contacted to obtain consent for more detailed information.
Five term infants were healthy and in the care of their mothers when they collapsed. The outcome was universally poor, and no cause was found. All neonates had a postmortem. In one infant dying soon after birth, scarring with widespread deposition of small deposits of mineral throughout the brain was found, clear evidence of global injury occurring in the antenatal period.
From limited case reports, the incidence of sudden unexplained neonatal collapse in hospital is 0.06 and 0.5 events per 1000 live births, but wider population data do not exist.23 Of this unexplained group mortality is reported at 50% with significant neurological sequelae in the majority of survivors. These data suggest an incidence of 0.4 cases per 1000 term live births but do not include less life-threatening events.
All the infants collapsed while being cared for by primiparous mothers in a hospital setting, unsupervised by staff. Primiparous mothers have less experience in the normal behaviour of newborn infants and may not recognise if the infant’s appearance or activity is abnormal. In addition, following labour and delivery, their awareness may have been impaired by fatigue and the effects of analgesia, or they may have been distracted by simultaneous painful procedures.
Two infants collapsed while lying face down on their mother’s chest and two while sharing a bed with their sleeping mothers. Early skin-to-skin contact has shown benefit in the rate and duration of breastfeeding, and maintenance of infant temperature and blood glucose, and is recommended by Unicef in its Baby Friendly Initiative.4 Most mothers and infants establish early skin-to-skin contact successfully and safely, but the association between positioning the infant prone and apparent life-threatening events in the early newborn period is well described.5
Bed sharing is common practice, but the potential risk of airway obstruction is acknowledged and was found in one study to be seen significantly more often, and for a significantly greater duration, than in infants cared for in cots.6 The Foundation for the Study of Infant Deaths does not recommend bed sharing during sleep before 6 months.
The cause of death in all five infants remains unexplained. It has been proposed that Sudden Infant Death Syndrome in older children may result from a combination of an exogenous stressor occurring during a critical period in a vulnerable infant. We postulate that during the critical transition from fetal to extrauterine life, some vulnerable infants, such as Case 1 in our series who had antenatal brain injury, may maladapt to a hypoxic stressor. This may be precipitated by positional airway obstruction when prone or breastfeeding, both almost universal features of such infants reported in the literature.7
Although a protocol exists for the investigation of sudden infant death in infancy, there is no standard approach to the investigation of infants who die in the early neonatal period. A survey of members of the British Association of Perinatal Medicine suggests that the approach to investigation within the UK is highly disparate, and not all infants undergo postmortem (Becher JC, personal communication. Survey of Members of the British Association of Medicine, September 2007).
Our series, in keeping with the literature, suggests that infants collapsing in the early newborn period have a high mortality and morbidity. This group of infants is unrecognised in national statistics, and so incidence in the population remains uncertain. National surveillance studies are under way in both Germany and the UK, and will investigate the causes of early sudden neonatal collapse, with a view to identifying those at risk and determining optimal practice in the care of the term infant.
Competing interests J-CB and AJL are conducting an epidemiological study through the British Paediatric Surveillance Unit of early sudden unexpected postnatal collapse.
Patient consent Obtained from the parents.
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