Time magazine reported in June that Joseph Sullivan said a pact made by a group of teens to get pregnant and raise their babies together was at least partly behind a spike in pregnancies at Gloucester High School. Seventeen girls at the school became pregnant this year - four times the usual number.
Sullivan later said he did not recall using the word "pact" but believed many of the pregnancies were intentional.
The theory arose amid a debate over whether to dispense contraceptives at a school health clinic without parents' knowledge.
Mayor Carolyn Kirk said at a June 23 news conference that she and school officials could not confirm the existence of a pact and had not invited Sullivan to the news conference because they could not verify his comments.
The principal said in a statement released by his attorney Tuesday that he believes the mayor "publicly slandered my reputation, my integrity and my intelligence" at the news conference.
"The ramifications of this whole episode on me and ... my family have been devastating and the Mayor's actions and the Superintendent's public silence has forced me to recognize that I have neither the trust, confidence or respect of the Mayor nor the Superintendent," Sullivan said in the statement sent to the Gloucester Daily Times.
He said he was resigning effective Friday and would retire.
"I have at all times tried to fair and honest with the students, the faculty, the staff and the community," he said. "At all times I have done what I have felt was in the best interests of the high school."
Kirk said in a statement Tuesday that "Dr. Sullivan will long be remembered in Gloucester for the many individual families he helped over the past 10 years. I wish him all the best in his retirement."
She did not immediately return calls to her office and home seeking further comment.
Officials have started an extensive study of teen pregnancy in Gloucester, including a review of the city's sex education programs and whether the school's 8-year-old day care center sent a message approving of teen motherhood.