School officials became suspicious in October after the number of girls asking for pregnancy tests in the Gloucester High School clinic unexpectedly spiked, Time Magazine reported Wednesday.
Seventeen students were pregnant by this school year's end, at least four times more than last year, the report said.
Principal Joseph Sullivan said almost half of the expectant girls, all aged 16 or younger, admitted they became pregnant after making a pact with friends to raise their children at the same time.
Gloucester residents have said the pregnancy spike could be an indirect result of the area's declining fishing industry and struggling workforce.
"Families are broken. Many of our young people are growing up directionless," school superintendent Christopher Farmer said.