Deaths attributed to Sudden Infant Death Syndrome dropped by half in the 1990s due to a campaign to put babies to sleep on their backs, but recently reported declines are likely illusory, a study said Monday.
Medical examiners, coroners and others charged with determining cause of death have been classifying more of the mysterious infant deaths as by suffocation or from unknown causes rather than from SIDS, which itself is a general term for unexplained infant death.
“There’s been this general feeling out in the community of pathologists and people who certify deaths (of) reticence to assign SIDS as the cause of death,” study author Dr. Michael Malloy of the University of Texas Medical Branch in Galveston said in a telephone interview.
Health authorities now require a death scene investigation prior to certifying SIDS as a cause of death. Such information can yield clues to whether pillows, blankets or loose bedding might have led to suffocation. If no investigation is done, then the cause of death is usually listed as unknown.
After SIDS first was recognized in 1969 it was listed as a cause of death more frequently, reaching one-third of unexplained infant deaths in 1975, the study said.
Stable death rate overall
In 1992, the American Academy of Pediatrics began recommending parents put infants under a year old to sleep on their backs and to remove loose bedding from cribs. Public campaigns began two years later, and U.S. SIDS deaths fell by about half to between 2,000 and 3,000 a year.
But the study, which was published in the academy’s journal, Pediatrics, concluded the reported 9 percent decline in SIDS deaths between 1999 and 2001 -- the last year for which data was available -- may not be valid.
During the same three-year period the overall infant death rate remained stable while deaths attributed to suffocation or unknown causes rose, indicating blame was shifted away from SIDS, Malloy wrote.
European studies have produced similar findings that SIDS has been reported less often in recent years, he said.
“(There has been) a stagnation in progress in getting parents to put babies down to sleep on their backs. Fourteen percent of the population is still putting babies down prone,” Malloy said. “(But) we think the (Back to Sleep) program has been effective.”
“We’ve definitely come a long way and we don’t want to see this classification issue undo the recommendations and their effectiveness,” said Laura Reno of the SIDS support group First Candle/SIDS Alliance. She said her group is working with health experts to improve consistency in applying the SIDS classification to deaths.
Another report in the same issue of the journal suggested that swaddling babies -- wrapping them in a cloth or sheet --may help deter SIDS while also resulting in sounder sleeps.
The study monitored sleep for 16 babies who spent half the night swaddled and half unswaddled, and tested their reactions to noise of up to 100 decibels.
“Swaddling promotes more sustained sleep and reduces the frequency of spontaneous awakenings,” though it took less noise to spark brain activity in swaddled babies, wrote study author Patricia Franco of the Free University of Brussels.
The swaddled infants’ brain activity may be an indication of their heightened defense mechanism against SIDS, she said.
