SIDS rate decreased in full and preterm infants

NEW YORK (Reuters Health) - While there has been a comparable rate of decline in the risk of sudden infant death syndrome (SIDS) in term and preterm infants, preterm birth is still a risk factor for SIDS, according to study by New Zealand researchers published in the Archives of Disease in Childhood.

Preterm birth is well-recognized SIDS risk factor, Drs. E. A Mitchell and J. M. D. Thompson, from the University of Auckland, note. "We have reported an increased risk of SIDS associated with preterm infants both before and after the change in prevalence of prone sleeping position and the subsequent reduction in SIDS."

The researchers used national mortality data to determine whether there was a comparable decline in SIDS mortality rate in term and preterm infants. Also, data from two New Zealand studies were used to assess whether there were any differences in SIDS risk factors between term and preterm infants before and after the SIDS prevention campaign.

As mentioned, the decreased rate of SIDS was similar between term and preterm infants, the investigators, with the New Zealand Cot Death Study Group, found. Much of this decrease has been attributed to the marked decrease in the number of infants sleeping in the prone position.

The researchers also report that risk factors for SIDS were similar between the groups, except for birth order. In term infants, the higher the birth order (the more previous births) the higher the risk of SIDS. This was not the case for preterm infants.

"Over the last two decades there has been an increasing rate of preterm birth, which we have shown to be increasing at a greater rate in the higher socioeconomic groups," the authors explain. "Also there has been a change in the demography of women giving birth, with average maternal age increasing and parity decreasing over this same time period," they note. "This may provide a reason for the changed risk with parity and preterm status."

SOURCE: Archives of Disease in Childhood, February 2006.