The Macomb County Medical Examiner completed an autopsy Wednesday on a fetus that was found buried in the back yard of a home near Richmond.

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Michigan State Police exhumed the remains from behind a home on Armada Ridge Road in Armada Township on Monday.

After an investigation, police determined that prior to a miscarriage, the 16-year-old mother of the unborn child -- with the help of the 16-year-old father -- may have attempted to abort the fetus.

"Without getting graphic, it involved a baseball bat," said Macomb County Prosecutor Eric Smith.

Smith said the male youth -- with the consent of the mother -- hit the pregnant teen in the abdomen with a decorative-type wooden baseball bat every other day for three weeks.

Dr. Daniel Spitz, chief medical examiner for Macomb County, told Local 4 that the cause of death was premature delivery with secondary trauma to the teen's abdomen.

The autopsy also revealed that the teen was six months pregnant at the time of the miscarriage, and not four months pregnant as she told investigators, Local 4 reported.

Spitz said he plans to report to the prosecutor's office that the unborn child was nonviable at the time of the miscarriage, the station reported. According to Merriam-Webster's Collegiate Dictionary, a nonviable fetus is not capable of surviving outside the mother's womb without artificial support.

Local 4 learned that based on that ruling, it is not likely that the mother will face charges.

"If it's a nonviable fetus, then we're talking about the destruction of an embryo and … in that case you can't charge the woman with it," said Smith.

The 16-year-old boy may also avoid charges because his actions appear to have been consensual, the station reported.

Prosecutors continue to investigate the possibility of mishandling charges against a mother of one of the teens, who said she buried the remains on advice from a local hospital.

The parents of the teens apparently did not know of the pregnancy until the miscarriage occurred, police said.