Prosecutors say the parents' religious beliefs led them to neglect their son's medical needs. But lawyers for Herbert and Catherine Schaible say the parents didn't realize the boy was dying.
The 2-year-old boy, Kent, died in January, about 10 days after he fell ill.
A Philadelphia judge this week upheld involuntary manslaughter, child endangerment and conspiracy charges against the Schaibles.
The Schaibles quit school after the ninth grade. They now work as teachers at their fundamentalist church, First Century Gospel Church and have several other children.