The examining room was full of people when little Ashley was brought in for her two month well-visit. Not only were mom and dad present, but she was accompanied by proud grandparents who brought a video camera to record the event.
I went through the routine questions to determine how she was doing as far as her general well-being and development. Her weight gain was excellent and mom was commended on successful breast-feeding.
Then we came to the subject of sleep. It seemed that Ashley was not the best sleeper, and mom felt that the baby did better when laying on her stomach. I began to explain why it was so important to have her sleep on her back, in the supine position .Grandmother interrupted. “With all due respect, I have raised five children and twelve grandchildren. ALL of them slept on their tummies and they are just fine!” Then Ashley’s mom apologetically added, “I know I’m suppose to have her sleep on her back, but she does seem to prefer her tummy…and I am getting a lot of pressure at home…if you know what I mean.” Grandmother continued, “And another thing. Ashley’s mom keeps putting that darn pacifier in her mouth every time the baby is put down. I know that can’t be good for her teeth when they do come in.”
Conversations such as this take place every day in pediatric offices across the country. On both counts, Ashley’s grandmother was wrong and this is a good lead-in on the subject of sudden infant death syndrome --SIDS. SIDS is the unexplained death of a previously healthy infant, under the age of one year. There is absolutely no explainable cause of death even after an autopsy has been performed. There are still around 2,500 cases of SIDS in the United States every year.
All through the 1980’s it was commonplace to have infants sleep in a prone position, or on their stomachs. In the late 80’s papers from Australia and New Zealand showed that having infants sleep in a supine position could decrease the risk for SIDS. There were many skeptics at first, and parents were concerned about the risks of aspiration should the babies spit up while flat on their backs. Nonetheless, statistics from abroad were compelling. In 1994 the American Academy of Pediatrics launched its “Back to Sleep” campaign whereby nurseries across the country instructed new parents to have their infants sleep in a supine position. This new idea was supported by the pediatricians at subsequent well-visits. The results were astounding.
Since 1994 the percentage of infants sleeping in a prone position has decreased from 70 percent to less than 15 percent. The rate of SIDS has decreased from 1.2 deaths per 1000 live births to 0.57 deaths per 1000 live births. There is no explanation for this dramatic fall in SIDS cases other than the supine sleeping position.
There are certain risk factors for SIDS. These include maternal smoking during pregnancy, overheating, soft bedding, prematurely, low birth weight and certain ethnicity, such as African-American, American Indian, and Native Alaskan.
No one knows the exact cause of SIDS. It is felt to represent a multifactor condition which is impacted by genetics, environment and sociocultural factors. Much research has gone into the study over the past few decades. One popular theory as to a possible cause has to do with an infant’s arousal state. When an infant is lying face down, the baby is much more likely to re-breathe, or “trap” carbon dioxide that has been exhaled with each breath. This is especially true if the child is lying on soft bedding with blankets, or on a pillow. When carbon dioxide is re-breathed, the level in the body goes up, at the expense of the level of oxygen. If no intervention takes place, this can lead to death.
In most individuals, there is an arousal system that will prevent this from happening. For example, the person will wake up or move the face in a protective manner. Recent studies have indicated that infants who die from SIDS have a dysfunctional arousal system. Thus they do not arouse appropriately when subjected to high levels of carbon dioxide and low levels of oxygen. Further studies have shown that there may be a genetic component to those infants who are at risk. It is known that a family who has suffered a loss from SIDS has a 2-6 percent chance of having another child succumb to SIDS.
Other risk factors for SIDS include prenatal exposure to tobacco smoke, sleeping with a pillow or soft mattress. One report showed that the combination of soft bedding and sleeping prone increased the risk of SIDS more than twenty-fold. Bed sharing, which has become more popular recently with the obvious advantages for the breast feeding mom, also increases the risk of SIDS. This is also true when having the infant sleep on a water bed or sofa.
Just as the “Back to Sleep” program has greatly decreased the incidence of SIDS, pacifier use has also been proven to decrease the risk by as much as 90 percent. (See the article in The Informed Parent archives on pacifier use.) One theory as to why it is protective has to do with the fact that it may lower the arousal threshold in a sleeping infant, thereby allowing the baby to adequately respond to rising levels of carbon dioxide. Regardless, the statistics are overwhelming that pacifiers greatly reduce the risk of SIDS in the first year of life.
After I shared this information with Ashley’s family, both mom and dad were convinced that she should learn to sleep on her back. I think that mom felt vindicated about the pacifier. I asked grandmother if this made sense to her, and if she had any question. She thought for a moment, all eyes turned toward her. “It all sounds like poppycock to me,” she said with a disbelieving shrug. “But, you’re the doctor, and all I want is what’s best for Ashley. So, from now on Ashley sleeps on her back, and as much as I don’t like it, we’ll use the pacifier.” There was a collective sigh of relief in the room as we were on the same page and I had the endorsement of the matriarch of the family. Then she added a cute postscript. “You know, I raised five children and twelve grandchildren…it was so much easier back then!”