An Oklahoma man has been charged with child sexual abuse after his 11-year-old stepdaughter gave birth at home earlier this month.

Dustin Walker’s wife, 33-year-old Cherie Walker, was charged with enabling child sexual abuse, NBC News reported.

As CrimeOnline previously reported, the girl gave birth at home on August 16 with no medical care, and the Walkers claimed they had no idea she was pregnant. Cherie Walker’s mother, who identified herself only as Michelle, said her daughter claimed the father was a 12-year-old boy and that the children just “got curious.”

The Walkers were initially charged with child neglect when they were arrested last week, but the charges were changed on Monday when DNA tests showed that Dustin Walker, 34, was a 99.9 percent match for the baby’s father.

“This is one of the most if not the most serious child sexual abuse and neglect cases I have ever prosecuted,” Muskogee County Assistant District Attorney Janet Hutson said in a statement.

The couple is also charged with six counts of child neglect for the 11 year-old girl and her five siblings, ages 2, 4, 6, 7, and 9. The children, who have been removed from the home, were found “living in deplorable conditions,” court documents say.

The 11-year-old had not seen a doctor in more than a year, officials said, and was apparently homeschooled.

The Walkers are due in court on September 3.