Study Reveals Why Smokers' Babies at Greater Risk of SIDS
As we have reported on many occasions, babies of smoking moms 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 moms are at greater risk of SIDS.
Even though the Back to Sleep campaign has reduced SIDS by 50%, it still 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.
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.
Comments
In a 2006 letter to the editor in the Journal of Pediatrics Dr. Rafael Pelayo, Dr. Judith Owens, Dr. Jodi Mindell, and Dr. Stephen Sheldon asked the following question of the American Academy of Pediatrics Task Force on Sudden Infant Death Syndrome after their Pacifier and Co-sleeping report was published:
"...from the perspective of the field of pediatric sleep medicine, the policy statement's laudable but narrow focus on SIDS prevention raises a number of important issues that need to be addressed. In particular, the revised recommendations regarding cosleeping and pacifier use have the potential to lead to unintended consequences on both the sleep and the health of the infant. The potential implications of a SIDS risk-reduction strategy that is based on a combination of maintaining a low arousal threshold and reducing quiet (equivalent to Delta or slow-wave sleep) in infants must be considered. Because slow-wave sleep is considered the most restorative form of sleep and is believed to have a significant role in neurocognitive processes and learning, as well as in growth, what might be the neurodevelopmental consequences of chronically reducing deep sleep in the first critical 12 months of life?"
In a currently utilized model that explains the process in which slow wave sleep is involved in memory consolidation the hippocampus acts as a temporary storage facility for new memories which are then transferred to the neocortex during slow wave sleep (SWS) [8]. In this model, acetylcholine acts a feedback loop inhibitor inside the hippocampus during REM sleep and wakefulness. The activity during the high cholinergic wakefulness period is believed to provide an environment which allows for the encoding within the hippocampus of new declarative memories. The low cholinergic environment during SWS is thought to then allow these memories to be transferred from the temporary storage of the hippocampus to their permanent storage environment in the neocortex and for memory consolidation [9, 10].
A significant way of decreasing slow wave sleep in infants is by changing their sleeping position from prone to supine. It has been shown in studies of preterm infants [11, 12], full-term infants [13, 14], and older infants [15], that they have greater time periods of quiet sleep and also decreased time awake when they are positioned to sleep in the prone position.
8. Hasselmo, M.E. 1999. Neuromodulation: Acetylcholine and memory consolidation. Trends Cogn. Sci. 3: 351–359.
9. Buzsáki, G. 1989. Two-stage model of memory trace formation: A role for “noisy” brain states. Neuroscience 31: 551–570.
10. Hasselmo, M.E. 1999. Neuromodulation: Acetylcholine and memory consolidation. Trends Cogn. Sci. 3: 351–359.
11. Myers MM, Fifer WP, Schaeffer L, et al. Effects of sleeping position and time after feeding on the organization of sleep/wake states in prematurely born infants. Sleep 1998;21:343–9.
12. Sahni R, Saluja D, Schulze KF, et al. Quality of diet, body position, and time after feeding influence behavioral states in low birth weight infants. Pediatr Res 2002;52:399–404.
13. Brackbill Y, Douthitt TC, West H. Psychophysiologic effects in the neonate of prone versus supine placement. J Pediatr 1973;82:82–4.
14. Amemiya F, Vos JE, Prechtl HF. Effects of prone and supine position on heart rate, respiratory rate and motor activity in full term infants. Brain Dev 1991;3:148–54.
15. Kahn A, Rebuffat E, Sottiaux M, et al. Arousal induced by proximal esophageal reflux in infants. Sleep 1991;14:39–42.