MIDDLETOWN, Pa. — A Pennsylvania woman charged with fatally smothering her 2-month-old son by passing out on top of him has waived her preliminary hearing.

By waiving the hearing Thursday, 23-year-old Arissa Ward, of Middletown, will now proceed to trial on charges of involuntary manslaughter and endangering the welfare of a child. WHTM-TV reports (http://bit.ly/2sOlkzH ) Ward told investigators last year she drank alcohol and smoked marijuana before she passed out on the couch with her baby.

Prosecutors say the baby had marijuana in his system from his mother’s breastmilk. An autopsy said the baby died from a combination of asphyxiation and smothering.