Indian-Americans have the highest percentage of sleeping with their babies among ethnic groups in New Jersey, but the lowest rate of sudden unexpected infant death (SUID), a Rutgers Biomedical and Health Sciences study shows.

Researchers attributed this paradoxical finding to a variety of compensatory factors, including Indian-Americans’ practice of placing their infants on their backs to sleep.

The study appears in the journal New Jersey Pediatrics.

“Conditions that substantially increase the risk of SUID while bed-sharing include smoking, alcohol use, and maternal fatigue,” said lead author Barbara Ostfeld, a professor of pediatrics at Rutgers Robert Wood Johnson Medical School. “Indian-Americans smoke and use alcohol less than other populations. In addition, grandparents tend to be very active in childcare, which reduces maternal fatigue. Apart from bed-sharing, poverty also increases the risk of SUID, and Indian-Americans have higher incomes.”

The American Academy of Pediatrics considers bed-sharing to be a high risk factor in SUID, which includes sudden infant death syndrome, accidental suffocation and strangulation in bed, and ill-defined and unknown causes in children under age 1 year.

“There is strong clinical information on the risks associated with bed-sharing,” Ostfeld said. “Our intent was to discover more about this little-researched demographic breakdown, so we can better understand the risk factors for SUID in all groups and create culturally sensitive health messaging.”

The researchers looked at the mortality rates of 83,000 New Jersey-born infants of Asian-Indian heritage over a 15-year period and safe sleep practices in a sampling of this population. Results showed that 97% of the surveyed American-born mothers of Asian-Indian heritage reported using a crib, compared to 69% of those who were foreign-born.

Although infants of the foreign-born mothers now residing in the United States had a higher SUID rate compared to infants of US-born mothers of Asian-Indian heritage, for whom no SUID was recorded, the rate was still lower than that of other populations: From 2000 to 2015, infants of foreign-born mothers of Asian-Indian heritage had a SUID rate of 0.14 deaths per 1,000 live births, compared to 0.4 in white, 0.5 in Hispanic, and 1.6 in black populations.

“Our study shows that improved compliance with American Academy of Pediatrics guidelines on supine sleep and avoiding bed-sharing is associated with a lower rate of SUID even in already low-risk groups,” said Ostfeld. “Larger studies are needed to better understand the complex variables that affect risk in sharing a bed with an infant.”