Understanding Sudden Infant Death Syndrome (SIDS): Causes, Risk Factors, and Prevention

Creator: Doctronic
Published: 2024-03-19

Medically reviewed by Alan Lucks | MD, Alan Lucks MDPC Private Practice - New York on March 19th, 2024.

Key Takeaways

Peak incidence occurs between 2-4 months of age, with 90% of cases happening before 6 months—rates have dropped 50% since the "Back to Sleep" campaign began in 1994.
Male infants face 60% higher risk than females, while premature babies (born before 37 weeks) have 4 times greater likelihood due to underdeveloped brainstem control of breathing and heart rate.
Maternal smoking during pregnancy triples the risk, and continued smoke exposure after birth doubles it—each cigarette smoked daily increases danger by 0.7 deaths per 1,000 births.
Room-sharing without bed-sharing reduces risk by 50% compared to separate rooms, while soft bedding, bumpers, and stomach sleeping can increase risk up to 13-fold.
Breastfeeding for at least 2 months cuts risk in half, likely due to improved immune function and reduced respiratory infections that may trigger fatal episodes.

Sudden Infant Death Syndrome, or SIDS, is the unexplained and sudden death of a baby under one year old, with no known cause of death. SIDS is also known as crib death or cot death, as it often occurs while a baby is asleep. In the United States, SIDS is one of the leading causes of death for infants, claiming the lives of nearly 1,400 babies each year.

Causes of SIDS

While the exact causes of SIDS remain unknown, doctors have identified several factors that may contribute to its occurrence:

Undiagnosed health problems, such as genetic issues or changes that cause certain health complications
Problems in the part of the brain that controls breathing, heart rate, blood pressure, temperature, and waking from sleep
Stress from factors like poor sleep position, secondhand smoke, or respiratory infections
Prolonged and repetitive stressful or painful experiences for a baby before or after birth

It is important to note that multiple research studies and safety reviews have found no connection between vaccines and SIDS.

When Does SIDS Most Often Occur?

SIDS is most common when babies are between 2 and 4 months old, but it can happen at any time during the first year of life. Although SIDS is not very common, it is crucial for parents and caregivers to be aware of the risk factors and prevention strategies.

Risk Factors for SIDS

While it is not possible to predict whether SIDS will affect your family, certain factors can increase the likelihood:

Sex: SIDS is slightly more likely to affect boys than girls.
Race: SIDS occurs most often among African Americans, Native Americans, and Alaska Natives.
Birth weight: Preemies, especially those born very small, are at a higher risk for SIDS than full-term babies.
Family history: A baby's odds of SIDS are higher if a sibling or cousin passed away from SIDS.
Maternal health: SIDS is more likely to occur if the mother is younger than 20, doesn't receive good prenatal care, or smokes, uses drugs, or drinks alcohol while pregnant or during the baby's first year.

How to Prevent SIDS

Parents and caregivers can take several steps to reduce the risk of SIDS and keep their little ones safe:

Understanding Sudden Infant Death Syndrome (SIDS): Causes, Risk Factors, and Prevention

Sleep Positions

Always place your baby on their back to sleep until they can roll over on their own. Remember the phrase "back to sleep" to help lower the risk of SIDS.

Safe Bedding

Use a firm, flat surface for your baby's bed with tight-fitting sheets. Keep pillows, blankets, and other objects out of their sleep area until they are at least one year old. Swaddling is safe for warmth, but only until they learn to roll over.

Sharing a Bedroom

Sleep in the same room as your baby, but not in the same bed, to reduce the risk of SIDS by half. Avoid falling asleep while sitting up and holding your baby.

Pacifier Use, Vaccinations, and Breastfeeding

Using a pacifier, vaccinating your baby, and breastfeeding can all help lower the risk of SIDS.

Temperature Control

Keep your baby cool while they sleep by not overdressing them and maintaining a cool, comfortable room temperature. Consider using a wearable blanket (sleep sack) that covers their body while leaving their face uncovered.

Avoid Substance Use

Do not smoke, drink, or use drugs during pregnancy and after your baby is born. These substances can be harmful to your growing baby and may make you a less alert or careful parent. Secondhand smoke can also increase the risk of SIDS.

Pregnancy Health

Maintain a healthy lifestyle during pregnancy by avoiding risky behaviors, eating a balanced diet, and attending regular prenatal checkups with your doctor.

For more information on SIDS and safe sleep practices, visit:

By understanding the risk factors and implementing safe sleep practices, parents and caregivers can help reduce the occurrence of Sudden Infant Death Syndrome and ensure a safer environment for their babies.

The Bottom Line

The "ABCs" of safe sleep—Alone, on their Back, in a Crib—remain the most effective prevention strategy, reducing risk by up to 70% when combined with smoke-free environments. While no intervention guarantees prevention, following evidence-based sleep guidelines dramatically improves infant safety. If you have concerns about risk factors or need guidance on safe sleep practices, Doctronic can provide expert answers quickly.