A Chicago teenager who gave birth to a baby boy has been charged in his death after she abandoned the newborn in a plastic bag outside her house.

Ana Rosa Mora, 18, allegedly gave birth at her Logan Square home on the morning of April 19. The teenager placed the baby inside a plastic bag from Walmart, left it outside her home on North Hamlin Avenue and went to sleep, the Chicago Tribune reported. The infant was dead by the time he was found by a construction worker several hours later.

Mora appeared in bond court on Saturday after being charged with first-degree murder. Prosecutors say the mother abandoned her son because she was afraid her current boyfriend would leave her once he learned the baby looked like her ex-boyfriend, the baby's father.

The infant was found along with the placenta and umbilical cord, the newspaper reported. The Cook County medical examiner concluded he died from asphyxia and possible exposure.

After giving birth the defendant returned to school on Monday and tried to tell staff members that her child was six months old. She even showed them pictures of a baby girl she found on the Internet, prosecutors said.  

But school officials at Kelvyn Park High School grew suspicious when Mora began asking if DNA could prove that the dead infant found outside her home was hers, prosecutors said. Mora was arrested on Friday after a school official called the police, the Chicago Tribune reported.

Mora told authorities her son was alive when she gave birth, but she left him in a passageway next to her home, the newspaper reported. The mother said her son looked like his father, whom she was no longer dating. She was afraid her boyfriend would notice the resemblance and leave her.

Mora is being held on $500,000 bond, the Chicago Tribune reported.