SUID rates were highest among American Indian/Alaska Native, Black and Native Hawaiian/other Pacific Islander infants.
Although infant mortality rates have declined since 1999, there was a recent spike in sudden unexpected infant deaths from 2020 to 2022, according to data published in JAMA Pediatrics.
"We were very surprised to learn that sudden unexpected infant deaths (SUIDs) have increased recently," Elizabeth R. Wolf, MD, MPH, assistant professor of pediatrics at Virginia Commonwealth University School of Medicine, told Healio.
Wolf and colleagues studied infant mortality data from 1999 to 2022 to identify patterns in SUID rates. Additionally, Wolf and colleagues compared infant mortality rates from 2018 to 2022 by race and ethnicity.
Overall infant mortality declined by around 24% from 1999 to 2022 (736 vs. 558 per 100,000), according to the study. The mortality rate among Black infants was more than double that among white infants (1,125.5 vs. 457.4 per 100,000), Wolf and colleagues reported.
The researchers saw decreases in most causes of death over the study period except SUIDs, which rose from 89.9 per 100,000 in 2020 to 100.5 per 100,000 in 2022.
SUID rates were highest among Black infants (237.9 per 100,000; 95% CI, 232-243.8), followed closely by Native Hawaiian/Other Pacific Islander infants (233.9; 95% CI, 189-286.3) and American Indian/Alaska Native infants (213.5; 95% CI, 189.5-237.4).
SUID rates were lowest among Asian infants (22.3; 95% CI, 19.3-25.3).
Compared with Asian infants, Black infants were more than 10 times more likely to die from SUID (rate ratio = 10.7; 95% CI, 9.3-12.3) and more than four times more likely to die from hypoxia and birth asphyxia (rate ratio = 4.2; 95% CI, 3-5.9) or unintentional injuries (rate ratio = 4.6; 95% CI, 3.3-6.8).
Similarly, SUID rates among American Indian/Alaska Native infants were 9 times higher than those for Asian infants (rate ratio = 9.6; 95% CI, 8-11.5). The incidence of unintentional injuries (rate ratio = 5.5; 95% CI, 3.2-9.3) and necrotizing enterocolitis (rate ratio = 2.8; 95% CI, 1.6-4.7) were also significantly higher among American/Indian/Alaska Native infants vs. Asian infants.
The researchers noted that the incidence of SUIDs among Native Hawaiian and other Pacific Islander infants was 10.5 times that of Asian children -- two racial and ethnic groups that are typically combined in studies.
The researchers hypothesized that COVID-19 and other respiratory illnesses, maternal opioid use and infant sleeping practices contributed to the increase.
Wolf said pediatricians should emphasize the importance of safe sleep practices with their patients' families, especially in the first 6 months infants' lives.
"Babies are often seen in unsafe sleep environments on social media," she said. "It is critical that these images are countered by clear public health messaging about how to reduce the risk of sleep-related death."