The mayor of Gloucester, Mass., said Monday there is no evidence that a group of teenage girls made a pact to get pregnant and raise their babies together, a theory floated by their high school principal.

"Any planned blood-oath bond to become pregnant — there is absolutely no evidence of," said Gloucester Mayor Carolyn Kirk, after a closed-door meeting with city, school and health leaders.

Absent from that meeting was Gloucester High School Principal Joseph Sullivan, who has not responded to repeated requests for comment after he was quoted last week in a Time magazine story saying nearly half the pregnant teens, all age 16 or younger, confessed to making a pact to get pregnant and raise their babies together.

The mayor of the city, which is 50 kilometres north of Boston, said she was uncomfortable having Sullivan there.

Kirk cited privacy concerns in refusing to answer many questions about the 17 girls who became pregnant this school year, quadruple the number of pregnant girls in the previous year at the school.

Kirk said she and superintendent Christopher Farmer have been in touch with Sullivan, and that he was "foggy in his memory" about how he came to his theory.

"When pressed, his memory failed," Kirk said.

Authorities have talked to school and health officials who work most closely with the children and Kirk said, "The people that worked with the children on a daily basis have said there has been no mention whatsoever of a pact."

Recently released U.S. statistics show Gloucester High School may not be alone in dealing with a rise in student pregnancies, with the 2006 numbers documenting the first nationwide increase in the teen birth rate in 15 years.

The U.S. has traditionally had the highest teen birth rate of all developed countries.

In Canada, the teen birth rate has fallen dramatically during the past two decades, with the latest available figures, for 2004, showing 13.6 births for every 1,000 teen females compared to the U.S. rate of 41.1, Statistics Canada says.

Farmer said the Time story did not distinguish between "a pact to become pregnant or a pact because we are pregnant."

He also said it was clear some of the girls weren't protecting themselves. The principal had said some girls gave high-fives and planned baby showers while others were sullen if their pregnancy tests at the high school clinic came back negative.

Farmer defended Sullivan saying, "I don't believe anyone has acted in particularly bad faith here."

With files from the Associated Press