IONIA, MI - A woman was arrested on first-degree child abuse charges Monday, four days after the 8-month-old boy she had been caring for was hospitalized with skull fractures, a brain bleed, and evidence of previous broken bones, his family and police said.

Ionia Department of Public Safety said the arrest came after police investigated the caregiver's Aug. 4 call to 911, in which the person watching a baby named Thomas told authorities the infant had fallen and hit his head on a hardwood floor in a home on N. Jackson Street.

Instead, Thomas' family alleges the babysitter told police she had thrown the child.

The child was taken to Sparrow-Ionia Hospital by Life EMS. When the seriousness of the injuries was determined, the baby was transported to Helen DeVos Children's Hospital in Grand Rapids.

After police obtained an arrest warrant, the babysitter was lodged in the Ionia County Jail. The charge carries a maximum penalty of life in prison.

Police have not released the caregiver's name.

While the caregiver is charged with one count of abuse, Thomas' family has detailed the baby's medical ordeal on a gofundme page and outlines the evidence of past abuse doctors found during X-rays.

On the fundraising page, the baby's mother, Rachel Pierson, talks about rushing to the hospital after receiving a call from her babysitter that her son had been injured:

In all, doctors discovered three skull fractures, earlier broken ribs that were starting to heal, and a broken leg.

While police investigated who was responsible for the baby's injuries, Pierson wrote that the couple's other children were being taken in by relatives. On Aug. 5, police cleared the couple to bring their other children home.

In the last few days, doctors also detected bleeding in Thomas' brain and abnormal eye movement, according to his mother's post. More tests were ordered.

As of mid-morning Monday, he was still being cared for at DeVos Children's Hospital.