Minnesota recorded 54 unexplained infant deaths in 2015 — about the same as prior years — and all but one involved a child in an unsafe sleeping environment, according to an analysis from the Minnesota Department of Health.

State health officials used the findings to renew their warnings to parents to place their babies to sleep on their backs and in uncluttered cribs.

The department released the analysis Wednesday during an event in Duluth to highlight efforts at St. Luke's hospital, where employees are trained annually on safe infant sleep positions and parents are counseled as well before going home with their new babies.

"Infant deaths from unsafe sleep practices are preventable, and we know training is critical," said Emily Piper, commissioner of the Minnesota Department of Human Services.

The analysis found 54 sudden unexplained infant deaths in 2015, including 53 that occurred while infants slept in unsafe environments. In most instances, the babies had loose objects such as pillows or blankets around them or weren't sleeping on firm surfaces such as crib mattresses. Those present suffocation hazards.

In half of the deaths, the babies were sleeping on beds or sofas with other people. One in four involved infants placed on their sides or their bellies, rather than on their backs, as is recommended.

Infant deaths in child care facilities have dropped sharply since 2012, following a Star Tribune investigative series on the problem and changes in state inspection, training and licensing practices. The state recorded 45 deaths in licensed child care facilities from 2008 through 2012. There have been just 10 since then.

However, the overall rate of sudden unexplained infant deaths hasn't changed in Minnesota — hovering since 2000 around eight deaths per 100,000 children born each year.

Some parents have been reluctant to give up favored sleeping practices, while some babies have medical needs such as digestive problems that require them to sleep on their stomachs.

Cultural differences on sleep practices appear to be a factor. The rates of sudden unexpected infant deaths are twice as high for infants born to black or American Indian mothers. Economic factors also play a role, given the costs of crib mattresses and "sleep sack" pajamas that are preferred over loose blankets for tucking infants into bed.

Nearly one in 10 new mothers report that their health care providers haven't talked to them about safe sleep positions, according to recent data from the Minnesota Pregnancy Risk Assessment Monitoring System.

Dr. Ed Ehlinger, the state health commissioner, urged doctors and hospitals to follow the example of St. Luke's, which received a national certification for its training on safe sleep practices.