Infant Car Seats May Increase Risk of SIDS

July 19, 2007

MONTREAL -- Newborns placed in a sitting position-in car seats, baby carriers, or infant seats, for example-may have an increased risk of sudden infant death, researchers reported here.

MONTREAL, July 19 -- Newborns placed in a sitting position -- in car seats, baby carriers, or infant seats, for example -- may have an increased risk of sudden infant death, researchers reported here.

A review of 508 deaths of infants younger than one year found that 17 deaths occurred when infants were in "sitting devices" and 10 of those deaths were unexplained, according to Aurore Ct, M.D., of McGill University Health Center, and colleagues, in a study published online by Archives of Disease in Childhood.

The authors said the greatest risk was for infants younger than one month, noting that six of the 64 infants who died within a month of birth (9.4%), were in the "seat group, whereas only 11 of the 444 infants older than one month (2.4%) were in the seat group, which represents an RR of 3.80 for the sitting position and is highly significant (P=0.006)."

When they categorized all deaths as explained or unexplained, 49 unexplained deaths had occurred in infants younger than one month and five of those infants were sitting at time of death, for an RR of 7.35 (P

The authors suggest two factors that could explain the excess deaths in newborns -- the fact that prolonged apnea, bradycardia, and drops in oxygen levels are most common during the first month of life and decrease thereafter and the length of time that the infant spent sitting, especially babies who had evidence of upper airway obstruction.

They said that five of the infant deaths occurred in babies who had been sitting for several hours and had laryngomalacia or other cranio-facial anomaly.

The authors said that an earlier study found that using an insert that holds an infant's head in a neutral position during sleep while in car seats reduced the number and severity of episodes of lowered oxygenation.

These inserts are currently recommended for use with premature infants, and are available at stores that sell baby equipment.

Dr. Anderson said that in the United States it is routine practice for pediatricians to conduct at "car seat challenge" before hospital discharge for premature infants or babies with upper airway obstruction.

During a car seat challenge the infant is placed in the car seat and then vital signs are carefully monitored for a time period that would correspond with the time required for the trip between the hospital and the infant's home.

The authors said their study was limited by the lack of a control group of healthy living infants, but they said that infants for whom a cause of death was found served as a nominal control group.