Weight gain and sudden infant death syndrome: changes in weight z scores may identify infants at increased risk.

AIMS: To investigate patterns of infant growth that may influence the risk of sudden infant death syndrome (SIDS). DESIGN: Three year population based case control study with parental interviews for each death and four age matched controls. Growth was measured from prospective weight observations using the British 1990 Growth Reference. SETTING: Five regions in England (population greater than 17 million, more than 470 000 live births over three years). SUBJECTS: 247 SIDS cases and 1110 controls. RESULTS: The growth rate from birth to the final weight observation was significantly poorer among the SIDS infants despite controlling for potential confounders (SIDS mean change in weight z score (deltazw) = -0.38 (SD 1.40) v controls = +0.22 (SD 1.10), multivariate: p < 0.0001). Weight gain was poorer among SIDS infants with a normal birth weight (above the 16th centile: odds ratio (OR) = 1.75, 95% confidence interval (CI) 1. 48-2.07, p < 0.0001) than for those with lower birth weight (OR = 1. 09, 95% CI 0.61-1.95, p = 0.76). There was no evidence of increased growth retardation before death. CONCLUSIONS: Poor postnatal weight gain was independently associated with an increased risk of SIDS and could be identified at the routine six week assessment.

Babies sleeping with parents: case-control study of factors influencing the risk of the sudden infant death syndrome. CESDI SUDI research group.

OBJECTIVE: To investigate the risks of the sudden infant death syndrome and factors that may contribute to unsafe sleeping environments. DESIGN: Three year, population based case-control study. Parental interviews were conducted for each sudden infant death and for four controls matched for age, locality, and time of sleep. SETTING: Five regions in England with a total population of over 17 million people. SUBJECTS: 325 babies who died and 1300 control infants. RESULTS: In the multivariate analysis infants who shared their parents' bed and were then put back in their own cot had no increased risk (odds ratio 0.67; 95% confidence interval 0.22 to 2.00). There was an increased risk for infants who shared the bed for the whole sleep or were taken to and found in the parental bed (9.78; 4.02 to 23.83), infants who slept in a separate room from their parents (10.49; 4.26 to 25.81), and infants who shared a sofa (48.99; 5.04 to 475.60). The risk associated with being found in the parental bed was not significant for older infants (>14 weeks) or for infants of parents who did not smoke and became non-significant after adjustment for recent maternal alcohol consumption (>2 units), use of duvets (>4 togs), parental tiredness (infant slept 2 people per room of the house). CONCLUSIONS: There are certain circumstances when bed sharing should be avoided, particularly for infants under four months old. Parents sleeping on a sofa with infants should always be avoided. There is no evidence that bed sharing is hazardous for infants of parents who do not smoke.

How much wrapping do babies need at night?

In a longitudinal, population based study, overnight temperature recordings were made in the bedrooms of 152 babies aged 3-18 weeks and the insulation provided by their bedclothing was assessed. Outdoor temperatures for the study nights were also available. Parents applied more insulation on colder nights with lower bedroom temperatures than on warmer nights (mean 8.5 tog at 15 degrees C minimum bedroom temperature falling to 4.0 tog at 25 degrees C). For a particular temperature they also applied 2 tog more insulation in winter than in summer. The amounts of bedclothing used in the home were compared with insulation levels predicted to achieve thermo-neutrality over a similar range of environmental temperature from heat balance studies in young infants. They corresponded closely. The average amount of bedclothing chosen for babies in Avon allows them to remain in thermoneutral conditions throughout the night. These values are proposed as broad guidelines for the thermal care of young babies at night.