Seasonal variation in sudden-infant-death syndrome

Sudden infant death syndrome and weather temperature

The relationship between the days on which sudden infant death syndrome (SIDS) occurred and the daily minimum temperature was examined in Auckland (1979-1984) and Christchurch (1979-1987). There was a marked winter excess of deaths in both regions. There was a significant negative correlation between the monthly mean minimum temperature and SIDS rate for both regions (r = -0.43, n = 347, P less than 0.0001). The monthly mean minimum temperature describes SIDS mortality equally as well as the three variables of daily minimum temperature, season and geographical location. There was a significant association of SIDS with minimum temperature 4 and 5 days prior to the death after adjusting for the effect of monthly mean minimum temperature. The days preceding death were on average colder than the other days, but the effect was small, especially when compared with the magnitude of the temperature differences between consecutive months.

Postneonatal mortality in south New Zealand: necropsy data review

Three southern New Zealand health districts had a postneonatal mortality rate of 8.1 per 1000 livebirths and a postneonatal sudden infant death syndrome (SIDS) mortality rate of 6.3 per 1000 livebirths for the period 1979-1984. This is one of the highest reported rates of SIDS. The 429 postneonatal deaths occurring during the period were assigned to one of four groups: unpreventable (n = 52), possibly preventable non-SIDS (n = 45), SIDS with minor abnormalities at necropsy or premorbid symptoms (n = 167), and SIDS with no abnormalities at necropsy or documented premorbid symptoms (n = 165). These groups were related to obstetric and perinatal data. For those infants classified as SIDS, the winter peak of deaths was particularly marked if death occurred after 3 months of age. These older SIDS deaths had more minor abnormalities at necropsy, a longer interval between time last seen or heard alive and found dead and more thymic petechiae.

Postneonatal mortality, sudden infant death syndrome: factors preventing the decline of infant mortality in France from 1979 to 1985

The sudden infant death syndrome (SIDS) is known to be associated with a peak in mortality rates at 3 months of age, and a seasonal peak in winter. The aim of this study was to analyse the relationship between the month of death, month of birth and age at death for cohorts of monthly births in France between 1979 and 1985. Statistics concerning the causes of death were collected and used to calculate life-tables firstly from SIDS and secondly from all other causes. They show that the specific age distribution at death was not the same for babies born in late summer or autumn as for other newborns. Total infant death rates were higher for cohorts born in the autumn, because of the peak in deaths from SIDS at about three months of age.

Seasonality in the sudden infant death syndrome

Distinctive epidemiological features of the sudden infant death syndrome (SIDS) are its age at death distribution and pronounced winter excess. Whether or not these effects are independent of the month of birth of the infant is uncertain. We used a loglinear model to separate the effects of age at death, month of death and month of birth amongst 6229 infants who died from SIDS in England and Wales during the period 1979-1983. The results suggest that month of birth and month of death independently influence the risk of the infant dying from SIDS, the risk related to month of death being much greater.

Sudden infant death syndrome and environmental temperature: an analysis using vital statistics

We examined the relation between the daily numbers of deaths ascribed to sudden infant death syndrome (SIDS) (n = 6226) and daily temperature in England and Wales over the five year period 1979-83. When the data were filtered to remove the dominant seasonal trend, and residual autocorrelation, we found a significant negative correlation of deaths with both the level and rate of change of temperature four to six days earlier, irrespective of age at death. Place of usual residence was obtained for 909 SIDS cases occurring during the unusually severe winter of 1981-82, and, using space-time clustering techniques, we confirmed previous findings of the lack of 'epidemicity' for this condition. These results are compatible with several previous hypotheses of the relation between the weather and SIDS and directly incriminate drops in temperature in the occurrence of the condition.

Serum magnesium level and sleep behavior of newborn infants

Polygraphic studies were performed in 14 full-term newborns. The sleep behavior of the infants was correlated to the serum Mg level. correlations could be demonstrated between serum Mg and active sleep, as well as between serum Mg and quiet sleep. With increasing Mg quiet sleep increased, whereas active sleep decreased. After Mg injection quiet sleep increased and active sleep decreased even more. There were also corresponding correlations between serum Mg and rapid eye movements, submental muscle tone, and gross body movements.