Laura Lynn Cross, 36, is said to have had a three-year sexual relationship with the boy and posed as his "mentor" so he could move into her home.
The pupil's father said he raised concerns with authorities about the pair being inappropriately close in 2012, but no action was taken.
Ms Cross resigned from her post as an English teacher at Buchtel High School in Akron, Ohio, in January 2015.
She is alleged to have begun grooming the pupil, who cannot be named, while he was in the school's eighth grade.
Laura Lynn Cross is alleged to have groomed a 14-year-old pupil before having his child.
She initially invited him to go swimming in her pool before he later began staying the night.
Ms Cross later convinced the pupil's mother to let her son move into her house in a court-approved "partial parental custody" arrangement.
The teacher said it would allow her to "mentor" her the boy.
She was arrested earlier this month after police learned she had given birth to the boy's baby in 2015.
The teenager's father contacted officers after being tipped off about the child. But he criticised the school and Tallmadge Police for failing to take action earlier.
"It was a straight failure from the system. From the school and the police, definitely," he told local TV channel News 5 Cleveland.
"Everbody I talked to I was frank with that my son was having sexual relationships with this woman, with a teacher.
"She had a hold on my son and [the police] told me he's not co-operating with us so we no can do nothing with it."
He added: "She's a schoolteacher. To get aroused by a child basically you have to be a sick individual."
Ms Cross has been charged with three counts of sexual abuse alleged to have taken place between August 1, 2013, and September 6, 2016.
She is being held in the Summit County Jail on a $100,000 (£77,000) bond.