Researchers may have discovered why babies whose mothers smoke during pregnancy have a far higher risk of cot death, or Sudden Infant Death Syndrome (SIDS).
A report published in the Journal Pediatric Allergy, Immunology, and Pulmonology shows evidence that nicotine could be interfering with the development of brain centres that control breathing.
SIDS is the leading cause of death during the first year of a baby's life: pre-natal exposure to cigarette smoke puts infants at a two-to-five-fold increased risk of SIDS.
However what was not known was how exposure to the chemicals in cigarette smoke in the womb increased this risk.
But researchers from Cincinnati Children's Hospital Medical Center in Ohio analysed evidence from a number of human and animal studies and found that nicotine exposure in the womb led to altered breathing patterns and ventilatory responses that compromised respiratory arousal and auto-resuscitation.
The study found that 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 Dr 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.
'Perhaps when young women are freed from the chains of tobacco addiction we can then truly say that "you have come a long way... for your baby."'
For more information on SIDs, contact the Foundation for the Study of Infant Deaths
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