According to the Centers for Disease Control and Prevention (CDC), about 3,400 babies in the United States die suddenly and unexpectedly each year, with 32 percent being due to “unknown causes.”
New research from Rutgers University says sudden unexpected infant deaths (SUID) are rare during the first month of life, but the causes and risk factors for these deaths vary even in that short time.
However, they found that the cause of death for infants later in the first month of life is more likely to be classified as sudden infant death syndrome (SIDS).
What is SUID?
The Centers for Disease Control and Prevention (CDC) define SUID or ‘sudden unexplained infant death,’ as the sudden and unexpected death of a baby less than one year old in which “the cause was not obvious before investigation.”
However, experts say that SUID is not the same as sudden infant death syndrome (SIDS), and that SIDS is instead a potential cause of SUID.
“SIDS stands for sudden infant death syndrome and is a possible cause of sudden unexpected infant death,” Jennifer Kurtz, DO, chief of neonatal medicine at Long Island Jewish Forest Hills, part of Northwell Health in New York, told The Epoch Times.
“In addition to SIDS, possible causes of SUID are suffocation/strangulation, and unexplained causes,” she added.
According to a CDC breakdown of Sudden Unexpected Infant Deaths by Cause for 2020
- Sudden infant death syndrome accounted for 41 percent
- 32 percent were attributed to an unknown cause
- 27 percent were due to accidental suffocation and strangulation in bed
First Month of Life Is ‘Crucial’
“SUID in the first month of life is rare,” study co-author and medical director of the SIDS Center of New Jersey, Thomas Hegyi, said in a statement. “However, data suggest that within that first month, there are differences in risk patterns for SUID based on age at death.”
He emphasized that the first month of life is especially crucial to study, as it is a time when mothers are in postpartum recovery, experiencing fatigue, establishing breastfeeding practices, and developing new household routines, which can influence SUID risk factors.
Researchers Analyzed 15 Years of Data
This retrospective, cross-sectional study was conducted from 2000 to 2015 and used de-identified public access data from the New Jersey State Health Assessment Data System for demographic information, and the SIDS Center of New Jersey’s de-identified SUID case database for cases with reported behavioral information.
Scientists then compared risk factors for SUID in the first week to those in the remainder of the first month in infants at or above 34 weeks of gestational age (time between conception and birth).
Youngest Infant Deaths Most Likely Classified as Ill-Defined, Unknown Cause
They discovered that out of 889 deaths of infants born at or above 34 weeks of gestation that were classified as SUID, 123 happened during the first 27 days of life and 24 occurred in the first week.
According to researchers, of the three commonly reported types of SUID:
- Sudden Infant Death Syndrome
- Accidental suffocation and strangulation in bed
- Ill-defined and unknown causes
It was the deaths of babies in the first six days that were most likely to be classified as an ill-defined and unknown cause when compared to infant deaths that happened from seven to 27 days, which were most often classified as SIDS.
Those That Died in First Week More Likely to Be Cesarean Births
Hegyi explained that mothers of infants dying in the first week were more likely to have been delivered by primary cesarean section.
“Which carries potential distraction risks such as postpartum fatigue, postpartum depression, or pain-relieving medication,” he said in a statement.
Hegyi noted that these “challenges” could result in poor positioning of the infant during breastfeeding or skin-to-skin contact.
“Especially with first-time mothers unfamiliar with signs of infant distress or who may be recovering from a Cesarean section, there can be an increased risk,” he continued.
Kurtz observed that in this study, researchers found that babies with SUID in the first week of life did not necessarily have the typical risk factors for SIDS.
“My possible theory for this could be that mothers recovering from cesareans are less mobile, and potentially less alert due to receiving anesthesia and pain medications,” she said. “This would lead to less ability to bond with their newborn. Additionally, these mothers might not notice if something were amiss if they are groggy.”
Mothers of Younger SUID Babies Had Fewer Risk Factors
The study also found that mothers of infants that died in the first week showed less evidence of common risk factors.
A greater proportion of women whose babies died during their first week of life were educated beyond high school and experienced adequate prenatal care.
This contrasts with the typical pattern of negative social and health risk factors typically associated with SUID.
There were also trends toward less smoking during pregnancy, which is a significant risk factor for SUID, and greater odds that this was the mother’s first birth.
The Cause of SIDS Remains Unknown
Kurtz said the causes of SIDS are still unknown.
“But we do know that risk factors for SIDS include being male, being premature (born at less than 37 weeks gestation), being exposed to secondhand smoke, and being a nonwhite baby,” she said.
She pointed out that SIDS occurs more often between one and six months of age, “but can occur anytime during the first year of life.”
Kecia Gaither, MD, MPH, FACOG, the director of Perinatal Services at NYC Health and Hospitals/Lincoln in New York City, noted that “the specific underlying pathophysiology of both of these clinical entities (SIDS, SUIDS) is unknown.”
However, she mentioned that there are “causal relationships” that exist for both.
“Two factors that distinguish the two are the time of occurrence, and cesarean delivery,” said Gaither. “The research is novel; however more is needed to solve the mystery of why both entities occur.”
Preventing SIDS/SUID
According to Kurtz, SUID can be prevented by adhering to safe sleep guidelines.
“Infants should be placed on their backs to sleep, in a crib, on a firm mattress, without any fluffy blankets, pillows, or crib bumpers,” said Kurtz. “Families should not smoke in the home where an infant resides.”
For more information on preventing SIDS/SUIDS, you can also follow safety recommendations from Safe to Sleep, which include:
- Keeping all objects, like toys, out of the sleeping area
- Sharing a room with the baby for the first six months
- Dressing your baby in clothing appropriate for the room temperature