Smoking and SIDS: The Connection Explained

Like we need one more reason not to smoke, especially during pregnancy (and even for the men in the house who create second-hand smoke): new science is telling us that the increased risk for SIDS (sudden infant death syndrome) among people exposed to nicotine is very real. And very explainable.

Sleep Review magazine is reporting a fascinating study that just came out, detailing why an infant's ability to respond to oxygen deprivation after birth is dramatically compromised by exposure to nicotine in the womb--even when that exposure is light to moderate.

Picture a baby lying face down in bed. A normal, healthy baby would sense it's being deprived of vital oxygen, and thus move its head. This is similar to the "flight or flight" response we get when we're in a dire situation and have to move fast to survive (our body moves without us really thinking about it).

But when a baby has been exposed to the chemical nicotine in the womb, apparently this instinctual arousal mechanism doesn't work so well. So the baby isn't quick enough to respond and save his life.

SIDS is rare, but it's one of the most common causes of death in babies between 1 and 12 months of age. Most babies who die of SIDS are between the ages of 2 and 4 months. It can be devastating for a family--what seems like a totally healthy baby suddenly dies during sleep.

We don't know what causes SIDS, but clearly there are risk factors for it, and smoking is one of them (no, not the baby smoking, but the mother and anyone else in the vicinity). Current studies are looking at possibly a problem in the brain that controls breathing during the first few months of life. But this new study plainly shows how nicotine can kill a much-needed survival mechanism in the early stages of life.

When a baby is born, it's exposed to low oxygen, which signals the adrenal glands to release chemicals called catecholamines. These catecholamines contain the famous fight or flight hormone adrenaline that tell the baby's lungs to reabsorb fluid, and to take its first breath. The heart also begins to beat more efficiently. This response mechanism remains in place for a few months after birth (so it's the adrenal glands that act as the baby's oxygen sensor).

But under the influence of nicotine, it appears this mechanism becomes dysfunctional. Granted, a baby would normally lose this mechanism in time as the central nervous systems takes over the controls of this critical response, but unfortunately when a baby loses this ability too early in the game of life, the door to SIDS opens.

Yet another reason to blow out the smoke. I know it's no easy task. But neither is grieving for a lost child.

This article is cross-posted at Dr. Breus's Blog, The Insomnia Blog.