King County Prosecutors have accused an Auburn couple of giving their 6-week-old baby son methadone.

Stacie McKay, 28, and Darin Teeters, 26, were charged this week with second-degree assault of a child. They are scheduled to be arraigned Oct. 7 at the Maleng Regional Justice Center in Kent.

According to court records, on Saturday, Sept. 13, McKay put into her expressed breast milk a small amount of the methadone she uses to treat her opioid dependence and left the apartment. Although the child started to have trouble breathing soon after Teeters fed him, according to court records, 25 to 30 minutes passed before his parents decided to rush him to MultiCare Auburn Medical Center, which transferred him to Seattle Children’s Hospital.

As doctors at Children’s later told police, they found in the baby’s system “a significant methadone intoxication,” 150 times what would have been expected had the infant ingested the drug via his mother’s breast milk.

McKay at first told police that the drug must have come from her milk. Although Teeters initially denied any knowledge of how the methadone got into his son’s system, according to court records, he later admitted that McKay told him after she talked to detectives that she had put “a tiny bit of her residual methadone” in the baby’s breast milk, “to help him with withdrawals and pain from his recent circumcision.” But Teeters insisted he had not known the drug was in the bottle he gave his son that morning.

McKay subsequently admitted that she had put the drug in her son’s milk.

According to court records, Teeters told detectives that he had not called 911 because he was afraid that Child Protective Services would take the baby away from him and McKay.

The baby is expected to recover.