When your newborn arrives, you will have many things on your mind. Is your baby eating (or pooping) enough? Are they too hot or too cold? Is it normal that your baby cries this often?
Perhaps one of the most terrifying topics parents tend to worry about is sudden infant death syndrome (SIDS). According to the National Institute of Child Health and Human Development, SIDS is a sudden and unexpected medical disorder that affects infants who appear healthy.
SIDS is the leading cause of death among babies between 1 month and 1 year of age. While deaths have remained stable since 2013, nearly 1,400 babies died from SIDS in the United States in 2020.
If SIDS is happening, your baby may not show many signs of trouble. If they are in your room, you may not hear them struggle. Thankfully, most deaths from SIDS are preventable. Read on to learn its possible causes and some things you can do to reduce your baby’s risk.
What causes SIDS?
The exact causes of SIDS are still unclear, and research is ongoing. However, there are some factors that can make your baby’s risk higher.
“In many, many instances, the cause of SIDS is due to internal factors that are impossible for anyone to control,” said Helene Felman, MD, a pediatrician with Banner Children's. “Most researchers believe babies who die of SIDS are born with one or more conditions that cause unusual responses to common internal or external stressors.”
Many researchers use the Triple-Risk Model to understand SIDS. This model argues that, for sudden infant death to occur, all three of the following conditions must be present:
- Vulnerable infant: Your baby has an underlying defect or brain abnormality that makes their bodies unable to prevent SIDS since their hearts, lungs and airways aren’t big enough or mature enough to protect them.
- Critical development period: SIDS occurs during a time of critical development, such as the first six months of life.
- Outside stressor: Your baby is exposed to a dangerous sleep environment, such as co-sleeping, soft bedding, being placed on their stomach or side or excessive use of blankets.
“Unfortunately, there is currently no way to identify babies who have these brain abnormalities, although researchers are trying to develop tests,” Dr. Felman said. “But there are a number of outside stressors that parents and caregivers can change in order to help reduce a baby’s risk.”
These outside stressors include:
- Babies who share a bed with other children or adults
- Premature or low birthweight babies
- Babies who sleep on their side or stomach
- Babies who sleep on a soft surface or have loose bedding
- Babies who are exposed to substances used by parents (nicotine, alcohol, marijuana, opioids or illicit drugs) before and after birth
- Babies born to a parent who had no or late prenatal care
How is SIDS diagnosed?
The diagnosis of SIDS is given when no cause of death can be identified following a death scene investigation, an autopsy and a review of a baby’s clinical history.
“SIDS is a diagnosis of exclusion,” Dr. Felman said. “When all other causes have been excluded.”
A checklist for practicing sleep safety
Because researchers are still investigating the possible causes of SIDS, there is currently no way to “prevent” the syndrome from occurring. However, you can vastly reduce your baby’s risk of SIDS.
Always place your baby on their back to sleep
This is the safest position for healthy babies. When on their backs, babies have the best ability to keep their airway (mouths and noses) open to the air.
“If placed on their sides or stomachs, their airflow can be blocked,” Dr. Felman said. “Additionally, the airway (trachea) provides a pathway to the lungs. That tube is on top when anyone sleeps on their backs.”
When your baby is lying on their back if they vomit or have a lot of saliva, the fluids go into their stomach, not their lungs where it can be dangerous. However, if your baby is on their stomach, the airway tube is on the bottom, and therefore gravity allows the fluids to enter the lungs, where it can cause problems with breathing.
If your baby is rolling over in their sleep, which usually occurs as early as four months, then you don’t need to put your baby on their back again. However, be sure there are no blankets or other items in the crib.
Put your baby to sleep alone in a crib, bassinet or playpen
In the first six months of life, it’s safest for your baby to share a room with you. However, don’t have your baby sleep with you in your bed.
“Placing a baby in bed with a parent (as opposed to within a safe sleep environment, like a crib or bassinet) increases their risk of SIDS tenfold,” Dr. Felman said. “If babies are placed on a soft adult mattress or happen to fall asleep on a couch, the surface is so soft that their immature lungs and airways and bodies can’t always turn to get air, and they are left to suffocate within the mattress or couch unless someone moves for them.”
Make sure the mattress is firm and covered tightly with a fitted sheet
Use a firm, clean mattress that’s in good condition. Avoid makeshift bedding that isn’t marketed for sleep, like Boppy pillows and DockATot. These are very dangerous for your baby and can affect their ability to breathe properly.
“Your baby should be placed on a firm surface that doesn’t indent (or dip down) when your baby is lying on it,” Dr. Felman said. “As well, the sleep surface, whether in a bassinet, crib or play yard, should not incline more than 10 degrees.”
Additional things to consider:
- Purchase products that meet the Consumer Product Safety Commission’s (CPSC’s) safety standards and register your products to ensure you get updates on any recalls. If a product doesn’t meet federal safety standards, don’t purchase it. You can also check with your local Social Services agency for help with low-cost or free sleep surfaces.
- Check that the crib mattress fits tightly in the crib.
- Move your sleeping baby from a car seat, stroller, baby swing, infant carrier or sling to a firm sleep surface on their back as soon as possible.
Remove extra bedding, toys and soft objects from the sleep space
Objects in a crib or bassinet can increase your baby’s risk for suffocation, strangulation and getting trapped. Keep pillows, toys, stuffed animals, blankets, mattress toppers, bumper pads and weighted blankets out of the sleep area.
If you’re using a portable cot, only use the firm, thin, well-fitted mattress that comes with it. Don’t add a second mattress.
Dress your baby in lightweight clothing
Avoid over bundling, overdressing or covering your baby’s face or head. Your baby should be kept warm, but they shouldn’t be allowed to get too warm. Overheating is a risk factor for SIDS.
“If you’re concerned about your baby getting cold, dress them in layers or use a wearable blanket, but be mindful of overheating,” Dr. Felman said.
Don’t worry if their hands or feet feel cool – this is normal. Keep the temperature of the room comfortable. A good rule of thumb is never to give your baby more than one more layer than what you are comfortable wearing. For example, if you are wearing a t-shirt and shorts, your infant can be wearing a onesie and a light, wearable blanket.
Always maintain a smoke-free environment, before and after birth
Don’t smoke when you’re pregnant and don’t let anyone smoke around your baby.
Avoid sleep-positioning devices or home monitors
“Save your money,” Dr. Felman said. “Products that claim to reduce the risk of SIDS only give parents a false sense of security and there is no evidence they reduce the risk of death.”
Position the crib away from windows
Place the crib at least two feet away from heated vents, windows, window-blind cords, drapery or wall lamps and one foot from walls and furniture.
Windows pose a significant risk to babies and toddlers. Window falls and curtain cord-related injuries are common in children under five. It is never a good idea to place a crib or bassinet in front of or near a window.
Additional ways to reduce the risk
Apart from sleep safety, there are a few other recommendations to reduce the risk of SIDS. Some of these include:
- Place your baby on their stomach while awake and you’re watching them. Tummy time for full-term babies starts in the first week once their umbilical cord stump falls off. This helps your little one develops fine motor development and neck strength and prevents flat head syndrome like plagiocephaly. The goal is to have them on their tummies while awake for 15-30 minutes per day by 7 weeks old.
- Breastfeeding is strongly recommended for at least six months because of its association with a reduced risk for SIDS and other protective effects.
- Early and regular prenatal care is essential. Don’t skip prenatal visits if you’re pregnant and well-checks for baby.
- Make sure your baby is up to date on vaccinations.
- Pacifiers at naptime and bedtime are recommended but wait until breastfeeding is well established before starting. (P.S. It’s OK if your baby doesn’t want a paci.)
- Give guidance to anyone (babysitter or caretaker) who is caring for your baby in your absence to ensure they are up to date on what to do and NOT to do at naptime and bedtime. Things may have changed since the last time they cared for a child.
Got further questions?
Don’t hesitate to contact your baby’s health care provider.