An Australian study has put to rest one possible contributor to sudden infant death syndrome. Gender differences in arousability are not a reason why male infants are more vulnerable to SIDS, researchers report.
The study published in the August 1st issue of the journal SLEEP concluded that males are initially easier to wake during quiet sleep, but by 2 to 3 months, the peak age for SIDS, there is no difference in arousal.
The study used daytime polysomnography to evaluate 50 healthy infants at 2-4 weeks and 2-3 months after birth. Infants slept on their backs as researchers tested for arousability by repeatedly spraying a burst of air into the child’s nostril until they woke.
Researchers had expected that males would be sounder sleepers. The opposite was the case; boys were easier to wake up at 2-4 weeks of age. In the follow up at 2-3 months the boys and girls had the same response.
Parental response may account for the gender disparity. Researchers suggest that more parents may put boys to sleep on their stomachs because they cry more and wake more often during the night.
SIDS is the leading cause of death in all infants and occurs at a 60 to 40 male to female ratio. The exact cause remains unknown, but recent research suggests some babies may be more vulnerable than others. Infants who died from SIDS have low levels of serotonin in the brain tissue.
Parents can reduce the risk for SIDS by placing babies to sleep on their backs, in a firm but not too warm sleeping environment.