Sept. 1, 2004 -- A readily available screening test may help predict which infants are at risk for sudden infant death syndrome (SIDS), according to new research.
SIDS is the most important single cause of infant death in the industrialized world, and little is known about what contributes the mysterious syndrome. The only potential risk factors identified so far for the condition are placing infants to sleep on their stomach or exposure to second-hand smoke.
A large Scottish study shows that a readily available blood test performed on mothers during the fourth through sixth months of pregnancy, which measures a protein called alpha-fetoprotein, may help predict the risk of SIDS. An elevated level during midpregnancy is also a strong predictor of stillbirths and Down syndrome.
Researchers found the risk of SIDS among the infants of women with the highest level of this protein was 2.8 times higher than that among the infants born to women with the lowest level of the protein, even though the overall risk of SIDS was still very low.
Test May Predict SIDS Risk
In the study, which appears in the Sept. 2 issue of The New England Journal of Medicine, researchers examined a prenatal screening database for women in western Scotland that contained information on 214,530 women and their infants.
Among these women, there were 114 cases of SIDS reported. The study showed that the risk of SIDS rose with increasing levels of maternal alpha-fetoprotein, as measured during the second trimester.
The incidence of SIDS was 2.7 per 10,000 births among those with the lowest levels of the protein compared with 7.5 per 10,000 births among women with the highest levels.
The risk of SIDS was also associated with lower birth weight and premature birth, but the association between alpha-fetoprotein and SIDS remained significant even after adjusting for these risk factors.
Researchers say the association between levels of this protein and SIDS risk shows that stillbirth and SIDS may share common risk factors that are linked to problems which impair fetal growth and development during pregnancy.