Toronto, June 1 (IANS) Canadian researchers have found that smoking during pregnancy increases dangers of an infant dying of sudden death infant syndrome (SIDS). In their landmark study, researchers at the University of Calgary have also found that overheating infants in layers of clothing too can lead to crib deaths. As part of their study, the researchers subjected one group of pregnant rats to cigarette smoke generated by moderate smoking, while kept another group smoke-free.

After the pups were born, the researchers subjected them to situations to know how cigarette smoke might have affected them in the womb.

When the researchers lowered oxygen levels, but kept room temperature normal, they found that the pups whose mothers were not exposed to smoke breathed normally. But the pups whose mothers were exposed to smoke, gasped for breath.

Again, when the researchers lowered oxygen levels, but raised room temperature, they found the pups born to rats not exposed to smoke gasped but managed to breathe normally.

But, on the other hand, the pups born to smoke-exposed rats almost gasped to death.

From their study, the researchers concluded that the decreased oxygen supply caused by smoking affected unborn babies

And decreased oxygen supply combined with overheating can have deadly consequences for infants, raising risks of crib death.

By over-wrapping their new-born, the study warned, parents put them at higher risk of sudden death infant syndrome.