Lower Blood Pressure in Premature Babies May Increase SIDS Risk

A new study has found that infants born prematurely have lower blood pressure during sleep in the first six months of life, which could explain why premature infants are at an increased risk of sudden infant death syndrome (SIDS).

Researchers at Monash University (Melbourne, Australia) monitored the blood pressure of 25 preterm and 20 full-term infants at two to four weeks, two to three months, and five to six months of age using daytime polysomnography. A photoplethysmographic cuff around the infant's wrist measured blood pressure during both quiet and active sleep.

The study results showed that blood pressure was lower in the preterm group during both quiet and active sleep at all ages studied. In contrast, there were no differences in heart rate between the groups. Within the infants in the preterm group, blood pressure averaged lower at 2 to 3 months' corrected age (when the risk of SIDS is highest) compared with both 2 to 4 weeks' and 5 to 6 months' corrected age, and was lower in quiet sleep compared with active sleep at all ages studied. Heart rate decreased with increasing age and was lower in quiet sleep compared with active sleep at 5 to 6 months' corrected age. The study was published in the December 2008 issue of Pediatrics.

"Our recommendation is that additional research needs to be undertaken to determine whether preterm infants also have impaired cardiovascular control, as this may also contribute to the higher rate of SIDS in preterm infants, particularly when sleeping face down/on the stomach,” said lead author Professor Rosemary Horne, Ph.D., of the Monash Institute of Medical Research.

"Parents of both term and preterm infants should follow the advice of ‘SIDS and Kids' for infant safe sleeping practices and always sleep their infant on his/her back, keep their baby away from cigarette smoke and ensure that the baby's head cannot be covered by bedding,” added Professor Horne.

Sudden infant death syndrome (SIDS) is a syndrome marked by the symptoms of sudden and unexplained death of an apparently healthy infant aged one month to one year.
Approximately 20% of all SIDS cases occur in preterm babies, though preterm babies comprise only 8-10% of infants born.

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