Parental mental illness boosts SIDS risk

A new study in the Jan 2010 issue of Archives of General Psychiatry has found that infants born to parents who had an inpatient psychiatric history were much more likely to suffer sudden infant death syndrome or SIDS.

Webb R.T. and colleagues from the University of Manchester in the UK analyzed data on "parental psychiatric admission, maternal prenatal smoking, obstetric and social risk factors and cause-specific infant death from the Swedish population between 1978 and 2004.

Infants born to parents who had a history of parental inpatient care had a higher risk of SIDS. Additionally, they also found that the SIDS risk was 6.8-fold higher in infants whose parents both were ever admitted to hospital for any mental illness.  Even a mother or father who was alone admitted with any psychiatric illness was at a 2-fold higher risk of seeing his or her infant die from SIDS.

Infants born to parents with an alcohol/drug disorder were more likely to suffer SIDS.  A 6.5 fold increased risk was found associated with mothers who had the disorder while 9.5 fold increased risk was associated with both parents who had the alcohol and drug problems.

Another study released today in the Journal of the American Medical Association suggests that low serotonin levels may cause sudden infant death syndrome.

Hannah Kinney, MD at Children's Hospital Boston and coworkers, authors of the study, reported that infants who died from SIDS not only had low serotonin, but also low levels of serotonin receptors.

Compared to those who died from other acute incidents, infants who died from SIDS were found to have 26 percent lower levels of serotonin and 22 percent lower levels of tryptophan hydroxylase, which converts tryptophan into serotonin, and 50 percent lower in serotonin receptors.

Serotonin is believed to regulate breathing, heart rate and blood pressure during sleep.  The researchers suggested that with lower serotonin levels, infants could not respond to environmental stresses like re-breathing carbon dioxide when sleeping in the face-down position.

It is not known why some infants had low serotonin.

The researchers advised that to prevent SIDS, mothers should by all means avoid smoking and drinking during pregnancy, and until 12 months of age, infants should be put to sleep on their backs in a crib with a firm mattress.

By Jimmy Downs and editing by Denise Reynolds