The number of children who died while they were involved in Manitoba's child welfare system went up last year, according to a new report by the province's Children's Advocate.

The latest annual report from Darlene MacDonald, released on Tuesday, says her office investigated the deaths in 2011-12 of 61 children who were involved in the child and family services (CFS) system.

It's up from 53 deaths that were reviewed in the previous year.

MacDonald told CBC News the higher number of deaths that were reviewed in the past year was to be expected, as the number of children who were involved in the CFS system has gone up as well.

More than 9,400 children were in care as of 2011, an increase of 3,650 over the past seven years, according to the report.

Overall, fewer children died in Manitoba last year than the year before. A total of 163 child deaths were reported in the province in 2011-12 the past year, down from 156 in the previous year.

Of the 163 deaths, 148 involved Manitobans and 61 of them were involved in the child welfare system. Twelve were children who were in care.

Heavy case loads cited

The report says heavy case loads are to blame for a lack of contact between children in the child welfare system and their social workers.

Families in crisis are not always assessed properly, raising the risk to children and youth, the report added.

MacDonald said her office is particularly concerned with the number of children who died in what she described as unsafe sleeping environments.

She said since 2005, the office has investigated seven reports of children who died after sleeping with their parents.

One of the reported deaths happened within the past year, she added.

"Some of the child deaths we've examined were the result of co-sleeping arrangements, where entrapment or soft bedding were at play, or where caregivers accidentally rolled over on their children during sleep," MacDonald said.

MacDonald is calling for more education for parents about the issue.

Concerns about services

The Children's Advocate's special investigations review unit, which investigated the child deaths, found that in some cases there were concerns about services to the families involved.

Those concerns had to do with risk assessments and case co-ordination between stakeholders, among other things, according to the report.

MacDonald said her office, which advocates for children and youth involved in Manitoba's child welfare system, received a total of 2,382 requests for services last year.

Top concerns that were raised in those requests were related to children's rights, case planning and quality of care, MacDonald said in a release.

MacDonald added that her office has developed, with input from the four authorities that oversee child and family services agencies, a more collaborative approach to writing recommendations after child death reviews.

The full report has been posted on the children's advocate's website.