I was so afraid of SIDS, I couldn’t fall asleep the first night of Hudson’s life. When I couldn’t hear him breathing, I placed my hand under his nostrils, waiting for the small puff of warm air that would confirm he was still alive. The fear of SIDS would have kept me from sleeping all through the next few months if the bone-deep exhaustion of motherhood hadn’t pulled me under. While many people talk about how amazing life is when a baby sleeps, my baby sleeping was one of my biggest sources of anxiety. And really, how could we not be terrified of SIDS? Defined as the sudden, unexplained death of an infant under the age of one, SIDS usually occurs when the baby stops breathing during sleep. Understandably, we want to figure out why it happens, and how we can prevent it.
While there’s been significant research on the topic, there’s still not a clear understanding of why it happens. But there are many theories, and these have led to certain safeguards we can implement to minimize the risk of this heartbreak striking our families.
The common SIDS risk factors are listed in the sidebar below. But before we get into that, I want to note that rarely does one factor cause SIDS. Often, the following elements must be present for SIDS to occur — if just one is removed, SIDS is much less likely to occur:
Vulnerability: A defect or brain abnormality that impacts a baby’s heart or lung function (such as the serotonin condition described below) can make them more susceptible to SIDS. Essentially, this vulnerability makes it more difficult for the body of a baby faced with an environmental complication (see below) to trigger a protective response.
Environmental complication: While most babies can manage environmental complications like lying facedown on a mattress or overheating, babies who are vulnerable and are six months old or younger are less able to respond protectively and so are at higher risk for SIDS.
Developmental changes: Infants six months old and younger experience rapid growth and change. These changes could temporarily disrupt internal systems that impact breathing. This is one reason why SIDS is most common in babies between the ages of two and six months.
There’s not much you can do about baby’s vulnerability or age, but the “What to do” section (pages 224–26) helps you cancel out most environmental complications.
Common SIDS Risk Factors
Here are many of the most common risk factors for SIDS:
Issue with serotonin-producing neurons: Properly working serotonin neurons are needed to maintain the continued functioning of the heart and lungs. Here’s how it works: The brain facilitates the flow of oxygen to the heart and lungs. If someone has sleep apnea, for example, they stop breathing, and the brain gets alerted that there’s not enough oxygen and too much carbon dioxide. Then the brain triggers a protective process called autoresuscitation, which usually consists of big gasps.
The belief is that in some cases of SIDS this protective mechanism is not triggered. A study done by Harvard Medical School found that when serotonin-producing neurons are inhibited, the brain’s ability to autoresuscitate and save the body from apnea is impeded. Continued research could lead to screening that might help detect infants at higher risk for SIDS.
Sleeping facedown: According to the book SIDS Sudden Infant and Early Childhood Death: The Past, the Present, and the Future, the prone (facedown) position has been found to increase the risk of rebreathing expired gases, overheating, and accidental suffocation. Placing an infant on their side to sleep is also not recommended. In 1994, a campaign called “Back to Sleep” was launched, urging parents to lay babies on their back for sleep. This lowered the rate of SIDS by 50 percent.
Sleeping on a soft surface, or near soft objects: A soft sleep surface or objects that could cover a baby’s face (like blankets, pillows, or stuffed animals) increase the risk for accidental suffocation and overheating.
Rebreathing: This consists of a baby breathing in the air they just exhaled, which causes oxygen levels to drop and carbon dioxide to rise. Putting a baby to sleep on their stomach or having a blanket or other soft material in the crib that can cover their face can result in rebreathing.
Overheating: As overheating could cause respiratory issues or depress a baby’s ability to wake up, it’s been found to be a risk factor for SIDS.
Respiratory infection: An article published in the medical journal Hippokratia found that a mild degree of respiratory viral infection was observed in 80 percent of SIDS cases. In addition, a study published in Immunopharmacology and Immunotoxicology reported that common bacterial toxins found in the respiratory tract, in association with a viral infection, could contribute to SIDS in an infant during a developmentally vulnerable period. An infection can be especially dangerous for a baby sleeping on their stomach, as this prone position could increase airway temperature and stimulate bacterial colonization and bacterial toxin production.
Maternal smoking and secondhand smoke: Maternal smoking during pregnancy is considered one of the greatest risk factors for SIDS, as it can lead to premature birth and low birth weight (both risk factors for SIDS), diminish lung growth, increase the chance of developing respiratory infections, and impair the baby’s ability to wake themselves. And exposure to secondhand smoke after birth could impact the baby’s inflammatory response during an infection and limit their body’s ability to respond to threats to the heart caused by inflammation.
Being born prematurely: A study published in the journal Pediatrics found that many premature babies have impaired blood pressure control, meaning if they have a drop in blood pressure during sleep, their body wouldn’t be able to quickly respond. In addition, premature babies often have a higher risk of developing respiratory distress, do not have strong sucking and swallowing reflexes, and have a higher risk of infection because of an underdeveloped immune system.
Long QT syndrome: This heart rhythm condition can potentially cause fatal arrhythmia — when the heart beats too fast or slow or has an irregular pattern. According to a study in Journal of Biological Research, long QT syndrome accounts for 12 percent of SIDS cases.
Toxins from the mattress: While I want to be super clear that this theory hasn’t been thoroughly tested, I think it’s worth sharing. A New Zealand scientist and chemist, Dr. James Sprott, believes the phosphorous, arsenic, and antimony found in some fire retardants used on crib mattresses can mix with mold created from the baby’s urine, spit-up, and drool to create toxic gas. He believes the inhalation of this gas could contribute to SIDS. An additional theory is that body heat can contribute to the release of volatile organic compounds (VOCs) in mattresses.
Again, this theory hasn’t been conclusively proven, but I think it’s worth it to bypass this potential risk by purchasing an organic crib mattress from a company that’s Global Organic Textile Standard (GOTS) certified. If that’s too pricey, you may be able to prevent the release of these gases with a mattress cover specifically designed to block toxic gases. (If you’re wondering where the information about cosleeping is, go to question 97.)
As research continues, new potential causes of SIDS will likely be revealed. Your care provider can provide information about the most up-to-date SIDS research.
While there’s no foolproof way to prevent SIDS, the following can help you significantly reduce your baby’s risk:
Practice healthy habits during pregnancy. The American Academy of Pediatrics reports that babies of women who obtain regular prenatal care, do not smoke, and abstain from regular illicit drug and alcohol use during pregnancy have a lower risk for SIDS.
Put baby on their back for sleep. Even if your baby seems to be more soothed on their stomach, always put them to sleep on their back.
Breastfeed. The American Academy of Pediatrics states that babies who are exclusively breastfed have a 50 percent lower risk of SIDS, as breastfeeding provides the following benefits:
- Supports the baby’s ability to arouse from sleep more easily
- Decreases incidence of diarrhea, upper and lower respiratory infections, and other infectious diseases
- Supports the overall immune system
- Helps the brain systems that control breathing to mature
- Minimizes allergies that could cause inflammation in air passageways
- Reduces gastroesophageal reflux
- Supports the development of the oral cavity and throat muscles, helping to keep the airway open
- Enhances the mother’s awareness of the baby
Ensure that the crib is empty, and use a sleepsack. Have baby sleep on a firm mattress with a fitted sheet — there should be nothing else in the crib, not even crib bumpers. Regarding clothing, put baby in a breathable sleepsack, which is a “wearable blanket.” This allows them to stay warm without using a blanket that could bunch up around their face. If the weather is so warm that you yourself are using little more than a sheet for coverage, your baby will likely be fine in a onesie or a light sleepsack.
Create a cool environment. As it’s important to prevent overheating, keep the thermostat between sixty-eight and seventy-two degrees Fahrenheit, have a fan on in baby’s sleep area, and clothe them in the aforementioned sleepsack or onesie. In addition, it’s not advised to put them to sleep in a hat, as it can trap heat.
Open windows when weather permits. Fresh air helps keep the air in baby’s sleep environment cool and clean, minimizing SIDS risk factors. If the weather allows and you feel it’s safe, open the windows in your baby’s sleep zone, being sure to insert a window guard when they become mobile.
Cleanse air with plants and an air purifier. Enhance the cleanliness of the air in baby’s room by using an air purifier and placing one or two air-purifying plants in areas of the room they can’t reach. Plants that can cleanse the air of harmful toxins, like trichloroethylene, formaldehyde, benzene, and xylene, include the peace lily, Gerbera daisy, florist’s chrysanthemum, red-edged Dracaena, and English ivy.
Use a firm, GOTS-certified organic crib mattress or a toxin-resistant mattress cover. As the toxins in standard mattresses might increase the risk of SIDS, opt for a GOTS-certified organic crib mattress or wrap the mattress in a cover that’s a “toxic gas shield.”
Make sure baby’s bed adheres to Consumer Product Safety Commission (CPSC) guidelines. A government organization that oversees products sold in the United States, the CPSC provides recommendations for purchasing a safe infant bed; see “Safe Sleep — Cribs and Infant Products Information Center” at cpsc.gov/SafeSleep.
Skip swaddling. While the research is ongoing, a study published in Pediatrics found that swaddling might increase the risk for SIDS, as it could hinder a baby’s ability to wake up during cardiovascular stress.
Have baby sleep in your room for at least the first year of life. A report by the American Academy of Pediatrics recommends that babies sleep in their parents’ room for the first twelve months, as this can reduce SIDS by up to 50 percent. While there’s not a definitive reason for this outcome, it’s believed that a baby will arouse from sleep easier when sleeping in a room with others, and that parents are better able to monitor the baby when they’re in the same room.
Consider a bedside sleeper. These aptly named baby beds are essentially bassinets that can be pushed up next to your bed and readjusted so baby is level with you. Some also have a side that can fold down, allowing you to easily access baby. If you go this route, make sure you select a bed that meets CPSC safety standards. Ideally, it will have a thin and firm mattress that’s no more than an inch thick. In addition, net or mesh walls are preferred, as they increase air flow.
Stay away from cigarette smoke. As breathing in secondhand smoke can be incredibly harmful to infants, remove your baby from any area where someone is smoking. And because smoke can linger on furniture, carpet, and other material, it’s best to not have baby in the home of a smoker, which is why it’s strongly advised that any smoker who lives in the same home as an infant quit smoking. In addition, do not let anyone who smokes hold baby, as smoke can linger in hair and clothes.
Ensure that all babysitters and childcare facilities you utilize follow these safety guidelines. Whenever anyone else will be caring for baby, make sure they adhere to this sleeping protocol. If baby will be at a daycare, have someone there walk you through their protocol. You can also stop in during naptime to see them in action.
The same goes for a babysitter; walk them through your sleepy-time routine, ensuring they understand its importance by having them repeat it back to you. You can also provide a simple written reminder. For example, “Put baby to sleep on their back, in their designated, empty bed, without a blanket and in a sleepsack or onesie, depending on temperature. And turn on the fan.”
If a parent or in-law seems resistant, remind them that this is not a request. While they might have done things differently when their children were infants, it’s up to you how your child is put to sleep.
Contact your pediatrician if baby seems to have respiratory issues. As respiratory issues can be a SIDS risk factor, contact your care provider if baby has a cough, breathing issues, or any symptom that concerns you.