The couple, Stacie McKay and Darin Teeters, entered their pleas in King County Superior Court. The judge ordered them held on $200,000 bail. Prosecutors have also asked that the couple be barred from having contact with any children, including their own.
King County prosecutors contend McKay, 28, and Teeters, 26, fed the baby boy methadone earlier this month. The poisoning was discovered after he was rushed to Seattle Children's hospital.
The baby arrived at Children's shortly after 10:30 a.m. on Sept. 14 with high levels of methadone in his system. Writing the court, an Auburn detective noted the boy's methadone level was about 150 times what would be expected had he simply been fed breast milk from a mother using the narcotic.
McKay and Teeters initially denied giving methadone to their child. According to charging papers, Teeters then told police McKay admitted to him that she put "a tiny bit" of the drug - a pain killer often given to heroin addicts attempting to kick the habit - into the boy's bottle to help him with withdrawals and the pain of circumcision.
Confronted by police, McKay said she believed the boy was going through post-birth withdrawals, an Auburn detective told the court. According to charging papers, McKay claimed she returned home from the store to find that Teeters had fed their son from the bottle she'd tainted, and that the boy was having trouble breathing.
Teeters claimed he didn't call 911 because he was concerned Child Protective Services workers would pull the baby from their home, the detective continued.
Blood tests at Children's hospital showed the boy had been given a substantial dose of methadone, but a doctor said the little boy should not sustain any lasting or permanent damage from the drug.