London: Babies whose mothers smoke during pregnancy have a far higher risk of Sudden Infant Death Syndrome (SIDS), the leading cause of death during the first year of life. Now researchers think they know why -- nicotine could be affecting the development of brain centres that regulate breathing.
The link between maternal smoking and SIDS is well-established, reports the journal Paediatric Allergy, Immunology, and Pulmonology.
Prenatal exposure to cigarette smoke puts infants at a two to five-fold increased risk of SIDS and contributes to premature birth, which is another risk factor, reports the Daily Mail.
However, what was not known was how exposure to the chemicals in cigarette smoke in the womb increased this risk.
Researchers from Cincinnati Children`s Hospital Medical Centre in Ohio, US, analysed evidence from a number of human and animal studies.
They found nicotine exposure in the womb led to altered breathing patterns and ventilatory responses that compromised respiratory arousal and auto-resuscitation.
Babies of mothers who smoked during pregnancy had more pauses in breathing (infant apnea) and had a decreased ability to wake up from sleep in response to low oxygen.
Journal editor Harold Farber said: "These findings highlight the importance of public health policies to prevent the development of tobacco dependence in adolescent girls and the importance of treatment of maternal tobacco dependence prior to pregnancy."