A new study suggests babies exposed to cigarette smoke in the womb are more at risk for SIDS in warmer temperatures.

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Yet another reason to kick that nicotine habit: A new study attempting to explain why smoking during pregnancy may increase the risk of sudden infant death syndrome (SIDS) has found that prenatal cigarette smoke exposure in rats affected breathing responses and immune function of their offspring.

Researchers from the University of Calgary in Canada studied rats that were exposed to cigarette smoke in the womb—previous studies have shown that babies born to moms who smoke during pregnancy are more likely to develop infection—and compared them to a control group. Both groups were exposed to the same infection-causing bacteria, high ambient temperatures, and low-oxygen environments.

The researchers found that the smoke-exposure group had more episodes of apnea (temporary interruption of breathing), faster heart rate at warmer temperatures in rats with bacterial infection, and more inflammation-signaling proteins. They also found that maternal cigarette smoke exposure primed the inflammatory system to elicit a stronger response to bacteria.

In addition to the negative findings regarding prenatal smoking and SIDS, the study revealed that high body temperature and infection suppressed the heart rate response normally seen in a low-oxygen environment. And according to the researchers, human responses may be similar to those of the rats.

"Our observations emphasize the importance of minimizing risk factors for cardiorespiratory instability in infants including safe sleeping environment, avoidance of high microenvironment and body temperature, and maternal cigarette smoke exposure," they explained.

The takeaway? If you're pregnant or trying to become pregnant, kick your smoking habit. And if you did smoke while pregnant, know that avoiding germs and keeping Baby from overheating may help decrease the risk of SIDS.

Hollee Actman Becker is a freelance writer, blogger, and a mom. Check out her website holleeactmanbecker.com for more, and then follow her on Twitter at @holleewoodworld.