The 16-year-old, who had been undergoing chemotherapy, died from complications of the disease, said Dr. Antonio Cabrera, the legal representative for the hospital.
Her case stirred debate in her country, as her life was potentially at risk because of anti-abortion laws in the Dominican Republic.
Doctors were hesitant to give her chemotherapy because such treatment could terminate the pregnancy -- a violation of the Dominican Constitution, which bans abortion. Some 20 days after she was admitted to the hospital, she finally began receiving treatment.
The teen's body did not respond to the chemotherapy, and her condition worsened overnight, Cabrera said.
Her body also rejected a blood transfusion on Thursday, he said.
The patient then suffered a miscarriage early Friday, followed by cardiac arrest, he said. Doctors were unable to revive her.
Representatives from the Dominican Ministry of Health, the Dominican Medical College, the hospital and the girl's family had talked for several days before deciding to go forward with the chemotherapy.
The case sparked renewed debate over abortion in the Dominican Republic, with some lawmakers calling on officials to reconsider the abortion ban.
At the time that treatment started, Rosa Hernandez, the girl's mother, said she had been trying to convince doctors and the Dominican government to make an exception so that her daughter's life could be saved.
"My daughter's life is first. I know that (abortion) is a sin and that it goes against the law ... but my daughter's health is first," Hernandez said.
According to Article 37 of the Dominican Constitution, "the right to life is inviolable from the moment of conception and until death." Dominican courts have interpreted this as a strict mandate against abortion. Article 37, passed in 2009, also abolished the death penalty.