What Are the Major Contributors to Infant Mortality in the U.S.?

Although the United States is one of the wealthiest countries in the world, it has a high infant mortality rate in comparison to other high-income and developed countries. Understanding the major contributors or causes of infant mortality is crucial in efforts to effectively reduce the death rate. The leading causes of infant mortality in the United States in 2020 were:

• Birth defects
• Preterm birth and low birth weight 
• Sudden infant death syndrome 
• Injuries 
• Maternal pregnancy complications 

Birth defects are structural changes that are present in a baby’s body at the time of birth and are often accompanied by serious health conditions. Many birth defects are found during the first year of life. Some are visibly noticeable, such as a cleft lip.  But other conditions, such as hearing loss and congenital heart defects, can only be discovered through specialized tests. Additionally, although some birth defects have a known cause, such as fetal alcohol syndrome, there are numerous birth defects that have no identifiable cause. In these instances, birth defects may be influenced by factors such as genes, parental lifestyle and health behaviors, or exposure to potentially harmful elements in the environment. 

Preterm birth occurs when a baby is born before the 37th week of pregnancy. Since babies continue to grow and develop throughout the last weeks of pregnancy, preterm birth can limit the development of vital organs such as the lungs, liver, and brain. Low birth weight is often associated with preterm births and can increase the risk for additional complications since the baby may struggle to eat, gain and maintain weight, and recover from infections. Preterm birth and low birth weight were attributed to 16% of infant deaths in the United States in 2020.  

Sudden infant death syndrome (SIDS) is a term used to describe the death of a baby under the age of one year, whose death does not have a known cause. It is distinguished from sudden unexpected infant death (SUID), which is a broader term used to reference all sudden infant deaths or those that cannot be distinguished directly from SIDS. If the medical examiner or coroner cannot determine the cause of death, it may be categorized as SIDS on the death certificate. Similarly, when babies die due to injuries such as suffocation, strangulation, or other injuries, these may be categorized as SUID. 

Maternal health complications during pregnancy can also contribute to infant mortality. Some complications that commonly occur include infections, heart conditions, blood clots, high blood pressure, and stroke. These complications can also contribute to stillbirth, miscarriage, or the death of the mother during pregnancy or shortly after giving birth. It is important to note that if potential complications are identified early in the pregnancy, they may be managed more effectively or even prevented entirely with appropriate treatment and monitoring. 

Sources

“Infant Mortality”. U.S. Centers for Disease Control and Prevention. https://www.cdc.gov/maternal-infant-health/infant-mortality/?CDC_AAref_Val=https://www.cdc.gov/reproductivehealth/maternalinfanthealth/infantmortality.htm 

“About Birth Defects”. U.S. Centers for Disease Control and Prevention. https://www.cdc.gov/birth-defects/about/?CDC_AAref_Val=https://www.cdc.gov/ncbddd/birthdefects/facts.html 

“Fetal Alcohol Syndrome”. Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/fetal-alcohol-syndrome/symptoms-causes/syc-20352901 

“Preterm Birth”. U.S. Centers for Disease Control and Prevention. https://www.cdc.gov/maternal-infant-health/preterm-birth/?CDC_AAref_Val=https://www.cdc.gov/reproductivehealth/maternalinfanthealth/pretermbirth.htm 

“Definitions and Terms”. Safe to Sleep. https://safetosleep.nichd.nih.gov/about/terms 

“What is SIDS/SUID?” American SIDS Institute. https://sids.org/what-is-sidssuid/