Risk Factors for Death from SIDS Vary According to Baby’s Age, Says Study


A baby’s age influences risk factors for sudden infant death syndrome, according to new research.

Younger babies are more likely to succumb to SIDS when they’re sharing beds with others, while older babies face a greater risk when there are objects in their cribs, such as blankets or pillows.

The study is the first to show that risk of death from SIDS appears to change with the baby’s age, according to lead author Dr. Rachel Moon, associate chief of general pediatrics and community health at Children’s National Medical Center in Washington, D.C.

Bed-sharing is a big risk factor for SIDS death in babies under 4 months of age, said Dr. Moon. And for young, as well as older babies, it is important to insure that there is nothing else in a baby’s crib, other than the baby. This includes blankets, pillows, stuffed toys and bumper pads.

Dr. Moon added that parents sometimes relax these rules as the baby gets older and they see that nothing bad has happened. But the rule to follow is to always keep the baby’s crib completely free of anything other than the baby, even as the infant gets older.

Young babies are at risk of SIDS, also called “crib death,” because they lack the ability to push away objects that get on or near their faces, and they’re also unable to re-position themselves if another person with whom they’re sleeping moves and blocks the baby’s ability to breathe (with an arm, their body, etc.). But older babies who are able to grab things and move more are at greater risk of pulling a toy or a pillow to their faces, or to move into a position that blocks their breathing.

National Institutes of Health statistics show that more than 2,000 babies died from SIDS in 2010 in the United States, the most recent year for which statistics are available. Ninety percent of the babies were younger than 6 months, though crib death is considered a risk for babies up to a year old.

The study reviewed more than 8,000 infant deaths from sleep-related causes in 24 states, between 2004 and 2012. Close to 70 percent of the deaths occurred in infants who were sharing a bed when they died. An object like a blanket or a pillow was present in the babies’ beds in about one-third of the deaths.

Babies who were younger than 4 months were most likely to have been sharing a bed; they were mostly in an adult bed or sleeping on a person. Babies between 4 months and a year old were somewhat more likely to have had an object like a pillow or a blanket on the bed with them.

Soft, cushiony objects, like blankets, pillows or stuffed animals pose the highest risk for SIDS or suffocation to an infant, said Dr. Moon. The prevailing advice for avoiding crib death has been to place babies on their backs when they go to sleep, and never on their stomachs. But an older baby has the ability to grab a blanket or a pillow, for instance, even when they’re sleeping on their backs. This is why there should never be anything in the infant’s crib, in addition to placing baby on their back, and not sleeping with baby on a bed or a couch.

The study was published online in July, 2014 and in the August, 2014 print issue of Pediatrics.

SIDS is the leading cause of death in infants between 1 month and 1 year of age. SIDS isn’t a medical condition, but rather, it’s the diagnosis given when a baby under a year old dies suddenly, and the cause of death can’t be found after an investigation of the death scene, an autopsy and a review of the infant’s medical history.

Some experts believe that SIDS can often be the result of baby breathing in his or her own exhaled air, such as when a blanket or a stuffed toy gets near the baby’s nose, or when a baby is sleeping on its side too close to another person or a wall. By re-breathing his or her own exhaled air, the baby’s blood oxygen level drops, and the carbon dioxide level rises; the increasing oxygen depletion could cause or contribute to SIDS.

About 2,300 babies die from SIDS in the U.S. every year; most victims are between 1 and 4 months, and 90 percent of deaths occur in babies younger than 6 months. Death from SIDS usually occurs between the hours of 10 p.m. and 10 a.m., though it can happen at any time. It is also important to note that 20 percent of SIDS deaths happen in daycare settings, though babies spend much less time sleeping in daycare than at home. This point highlights the importance of insuring that everyone who cares for your baby know the guidelines for safe baby sleeping.

Babies Who Are at Higher Risk of Death from SIDS

Even though death from SIDS happens with no warning, certain factors put a baby at higher risk for crib death. Facts to consider include:

  • Cold weather increases the risk of death from SIDS
  • African-American babies are twice as likely to die from SIDS as Caucasian babies
  • Native American babies are three times as likely to die from SIDS as Caucasian babies
  • Smoking, drinking or using recreational drugs during pregnancy put a baby at higher risk of death from SIDS

Other risk factors for SIDS to keep in mind include:

  • Prematurity or low birth weight
  • Mother under 20 years old
  • Inadequate prenatal care
  • Exposure to secondhand tobacco smoke following birth
  • Soft, cushiony bedding, which can block baby’s breathing if baby should turn on his or her stomach
  • Overheating from too much sleepwear or blankets

Tip for Giving Baby’s Head a Little Lift, without Danger from a Pillow:

Fold a towel that’s not too thick into a quarter its size (fold in half, then fold again), and place it under the fitted sheet. That way, there is no danger of baby grabbing towel and bringing it near his or her face.

By Eirian Hallinan