Sudden Infant Death Syndrome (SIDS)
Sudden infant death syndrome (SIDS) is the sudden and explained death of a seemingly healthy baby.
Typically, a peacefully sleeping baby simply never wakes up. In most cases, no cause is ever found. Most SIDS deaths occur in children who are between 2 months and 4 months old. Sudden infant death syndrome rarely occurs before 1 month of age or after 6 months.
Although the exact cause of sudden infant death syndrome is still unknown, researchers have discovered some factors that may put babies at risk. They've also identified simple measures you can take to help protect your child from sudden infant death syndrome. Perhaps the most important is placing your baby to sleep on his or her back.
Over the years, researchers have investigated and ruled out a number of possible causes of sudden infant death syndrome, including suffocation, vomiting or choking, birth defects, metabolic abnormalities, and infection.
Exactly why SIDS occurs remains elusive, but many experts believe there are probably multiple factors that cause SIDS. For example, it's likely that an infant must have some sort of biological vulnerability, such as a heart or brain defect, combined with an environmental stressor, such as stomach sleeping, before SIDS can occur.
These things must also occur during a critical developmental period in the baby's life, typically during the first six months. These three factors — vulnerability, critical developmental period and outside stressor — combine to form what's known as the triple-risk model.
Research offers clue
In 2006, researchers discovered that abnormalities in a part of the brain that helps control breathing and arousal likely play a role in SIDS. Other research has focused on the way babies breathe while they're asleep — especially their response to low blood oxygen levels (hypoxia) — and on heart function.
Researchers are also continuing to investigate the link between SIDS and long QT syndrome, a subtle electrical disturbance in the heart that causes sudden, extremely rapid heart rates. A 2007 study found that almost one in 10 babies who died of SIDS had a genetic defect in one of the genes responsible for long QT syndrome. If you have a history of SIDS in your family, your doctor will want to check for the presence of long QT syndrome in your infant. This can usually be done withanelectrocardiogram (ECG) and confirmed, if necessary, with genetic studies.
One thing that is known is that childhood immunizations don't play a role in sudden infant death syndrome. After reviewing the available evidence in 2005, the American Academy of Pediatrics concluded that vaccines don't increase the risk of sudden infant death syndrome.
Risk factors :
Although sudden infant death syndrome can strike any infant, researchers have identified several factors that may increase a baby's risk. At higher risk are babies who are :
- Male. Boy babies are more likely to die of SIDS than girl babies are.
- Between 1 and 6 months of age. Infants are most vulnerable in the second and third months of life.
- Premature or of low birth weight. Your baby is more susceptible to SIDS if he or she was premature or had a low birth weight.
- Black or American Indian. For reasons that aren't well understood, race appears to play a role in SIDS. Cultural differences in child care practices — such as whether babies are placed to sleep on their backs — may be a factor.
- Placed to sleep on their stomachs. Babies who sleep on their stomachs are much more likely to die of SIDS than are babies who sleep on their backs. At highest risk are babies who are used to sleeping on their backs and are suddenly switched to stomach sleeping. At one time, doctors recommended stomach sleeping because babies rest more soundly in that position. But it's now known that stomach sleeping greatly increases a baby's risk.
- Born to mothers who smoke or use drugs. Smoking cigarettes during or after your pregnancy puts your baby at considerably higher risk of SIDS. Using drugs such as cocaine, heroin or methadone while you're pregnant also increases the risk.
- Exposed to environmental tobacco smoke. Infants exposed to secondhand smoke have a higher risk of SIDS.
- Born in the fall or winter months. More SIDS cases occur when the weather is cooler.
Also at risk are babies whose mothers had :
- Inadequate prenatal care
- Placental abnormalities — such as placenta previa, a condition where the placenta lies low in the uterus, sometimes covering the opening of the cervix
- Low weight gain during pregnancy
- Their first pregnancy at a young maternal (under 20)
Because a baby's head is still soft and pliable, some newborns placed to sleep on their backs develop a flattening of the back of the head (positional plagiocephaly). In most cases, the flattening is harmless and easily treated. If discovered early enough, simply changing the position of your baby's head will cause the flattening to disappear. At other times, your baby may wear an open-topped helmet to help restore a normal head shape.
You can usually prevent flattening from occurring in the first place by taking a few simple steps, such as :
- Holding your baby upright when he or she is awake.
- During close supervision, place your baby on his or her tummy to play. Make sure both you and the baby are in the same room and both awake when doing this.
- When you place your baby on his or her back to sleep, alternate the direction your baby's head faces. Or, alternatewhich end of the crib you place the baby's head — this will cause the baby to look both left and right, which helps round the head.
It also may help to change the position of the crib or the location of interesting objects, such as mobiles. That way, your baby won't consistently look in one direction. Once your baby is old enough to sit up, head flattening becomes less of a concern.
There's no guaranteed way to prevent SIDS, but you can help your baby sleep safely. Consider the latest guidelines from the American Academy of Pediatrics :
- Put your baby to sleep on his or her back. Place your baby to sleep resting on his or her back, rather than on the stomach or side. This isn't necessary when your baby's awake or able to roll over both ways without your help.
- Be sure your baby is placed to sleep on his or her back when staying with relatives or at child care. If your baby is used to sleeping on his or her back, it's especially important to avoid switching to the stomach position. Don't assume that others will place your baby to sleep in the correct position. Be sure to let them know that you insist on this for your infant.
- Don't smoke. A smoke-free environment is especially important during pregnancy and in your baby's first year of life. Infants whose mothers smoke during and after pregnancy are much more likely to die of SIDS than are infants of nonsmoking mothers.
- Select bedding carefully. Use a firm mattress, rather than a water bed or beanbag. Avoid placing your baby on thick, fluffy padding, such as lambskin or a thick quilt. These may interfere with breathing if your baby's face presses against them. For the same reason, don't leave fluffy toys or stuffed animals in your infant's crib.
To keep your baby warm, try a sleep sack or other sleep clothing that doesn't require additional covers. If you choose to use a blanket, make sure it's lightweight. Tuck the blanket securely at the foot of the crib, with just enough length to cover your baby's shoulders. Then place your baby in the crib, near the foot, covered loosely with the blanket.
- Place your baby to sleep in a crib or bassinet — not in your bed. Adult beds aren't safe for infants. A baby can become trapped and suffocate between the headboard slats, the space between the mattress and the bed frame, or the space between the mattress and the wall. A baby can also suffocate if a sleeping parent accidentally rolls over and covers the baby's nose and mouth.
- Keep your baby close by. Consider keeping your baby's crib or bassinet in your room at first. Infants who sleep in the same room — though not in the same bed — as their mothers have a lower risk of SIDS.
- Offer a pacifier. Sucking on a pacifier at naptime and bedtime may reduce the risk of SIDS. One caveat — if you're breast-feeding, wait to offer a pacifier until your baby is 1 month old and you've settled into a comfortable nursing routine. If your baby's not interested in the pacifier, try again later. Don't force the issue. If the pacifier falls out of your baby's mouth while he or she is sleeping, don't pop it back in.
- Moderate room temperature. Keep the temperature in your baby's room at a level that's comfortable for you, not warmer than normal. If your baby is sweating around the neck or face, it probably means he or she is too warm or has a fever or illness. When this happens, use fewer covers — not more.
Some parents feel more secure when their newborn's heart rate and breathing are monitored electronically. Unfortunately, monitoring is unlikely to prevent SIDS deaths.