A clue to why smokers’ babies at greater risk of SIDS

Most mums-to-be have heard the warnings to never smoke during pregnancy. Though it may seem like a common-sense rule to follow, many still aren’t heeding their doctors’ advice. And when an expectant mother opts to light up, it puts her unborn baby in harm’s way.

Babies of smoking mums are more likely to be born prematurely and have low birth weight, grow slower, and be at greater risk of sudden infant death syndrome (SIDS).

When babies are born too soon, their lungs aren’t as developed as full-term babies (born 38 to 42 weeks after the mother’s last menstrual period, or LMP). So preemies’ lungs often don’t function as well and they’re more likely to have breathing problems.

Looking at the oxygen levels of premature babies born between 28 to 36 weeks (both those of smoking and non-smoking moms), researchers found that the infants whose mothers smoked during pregnancy had a hard time coping when their oxygen levels dropped – their heart rates rose and they had pauses in breathing that lasted longer and were harder to recover from.

This, say the researchers, may offer insights into why babies born to smoking mums are at greater risk of SIDS.

Since the American Academy of Pediatrics (AAP) started the "Back to Sleep" campaign in the early 1990s, the occurrence of SIDS in the United States has dropped by more than 50%. But SIDS remains the leading cause of death in babies 1 month to 1 year old, and still claims the lives of about 2,500 US infants each year, usually between 2 and 4 months old.

Thankfully, though, the devastating syndrome is usually preventable. To help reduce the risk of SIDS for babies of all ages, make sure everyone who takes care of your little one – in and out of your home – follows these extremely important safety precautions:

• Unless your doctor says otherwise, always place your baby to sleep on the back – never on the belly or the side. Doctors now know that putting babies to sleep on their sides also puts them in danger of SIDS because of the risk that they’ll roll onto their bellies. (But it’s perfectly normal and OK for older infants, usually around 4 to 7 months, to roll onto their sides or bellies by themselves as they sleep.)
• Lay your baby down on the back on a firm mattress in a crib or bassinet – never on a pillow, waterbed, sheepskin, or other soft surface that your baby’s face can sink into.
• Never put your baby to bed with blankets, comforters, quilts, pillows, or plush toys.
• Don’t put your baby to sleep in your bed. Instead, keep the crib or bassinet in the room where you’re sleeping. You can bring your infant to your bed for nursing or comforting, but return your baby to the crib or bassinet to sleep.
• Never let anyone smoke around your baby both during pregnancy and after your baby is born.
• Consider putting your baby to sleep sucking on a pacifier.
• Breastfeed, if possible.
• Keep the room temperature comfortable and don’t over bundle your baby.
• Get early and regular prenatal care during your pregnancy and make sure your baby gets regular checkups throughout infancy.

And, of course, don’t smoke – during your pregnancy or once your baby is born. In addition to increasing your baby’s risk of prematurity and SIDS, when you smoke during pregnancy, you pass nicotine and carbon monoxide to your growing baby and also seriously raise the risks of stillbirth, low birth weight, asthma and other respiratory problems, childhood cancer, leukaemia, lymphomas, and brain tumours.

Second-hand smoke is also extremely unhealthy for children of all ages – it contains 250-plus chemicals proven to be toxic or carcinogenic (cancer-causing), from arsenic and ammonia to hydrogen cyanide. What’s worse, concentrations of many of these chemicals are higher in second-hand smoke than in the smoke inhaled by the smokers themselves!

If you’re pregnant and having a hard time quitting smoking, talk to your doctor about how to get the help you need to stop now and stay smoke-free in the future – for your sake and your baby’s. And during your pregnancy and after your little one is born make sure others do the same – or at least take their bad habit elsewhere.

(Source: American Journal of Respiratory and Critical Care Medicine: Nemours Foundation: September 2008)