Freshman state Rep. Doreen Gallegos received wide bipartisan support for the bill, her first to clear the House.
Her measure carried 56-12. All the opponents were Republicans.
Gallegos, D-Las Cruces, said the bill's intent was to make certain that access to education remains steady for pregnant girls or mothers and fathers who are still in high school.
No fewer than three House members became pregnant as teenagers. Two supported the bill but the third, Republican Rep. Monica Youngblood of Albuquerque, opposed it.
Youngblood said she and 10 or 15 other girls from her high school class were teen mothers, and all but a couple graduated.
Dangling extra excused absences in front of young mothers could backfire by creating a climate in which it is easier for them to stay away from school, Youngblood said.
Rep. Kelly Fajardo, R-Belen, disagreed.
As a pregnant teen, she said, she had supportive people around her, even as others told her she would amount to nothing. Fajardo voted for the bill because she said it would help girls keep working toward a diploma and not lose faith in themselves.
Perhaps the most moving story came from Rep. Georgene Louis, who became pregnant as a sophomore in high school.
Louis, D-Albuquerque, said she left her regular high school for a time because she feared she would fall behind academically with the responsibilities of motherhood. Instead, she traveled every day to a specialized school for pregnant girls and mothers.
With this bill, pregnant girls will not face such disruptions, she said. They will be able to stay in their neighborhood school, complete their academic work and graduate, said Louis, now an attorney.
Several Republicans who voted against the bill said it afforded special opportunities to girls and boys who got themselves in trouble.
"It looks to me like it's incentivizing (teen pregnancy). There are no repercussions," said Rep. Anna Crook, R-Clovis.
But Rep. Patricia Roybal Caballero, D-Albuquerque, spoke for the majority when she said the bill was at the heart of what all legislators campaigned on.
All said they wanted healthy communities and strong families. The bill to keep pregnant girls and young fathers on a path to graduation does that, Roybal Caballero said.
Gallegos' cosponsor on the bill was Rep. Alonzo Baldonado, R-Los Lunas, a relentless opponent of abortion.
The measure allows for 10 days of excused absences for teen parents, plus a restricted opportunity to make up academic work. The makeup period would be equal to the number of days the student was absent.
Gallegos said students need not take any days off. But the cushion is there in case of sickness or complications, she said.
Her proposal, House Bill 300, now goes to the state Senate for consideration.