George W. Bush’s pro-life stance solidified when he was a teenager in Texas — after his mother suffered a devastating miscarriage and showed him the fetus in a jar, the former president said in an extraordinary interview that airs tonight.

“She said to her teenage kid, ‘Here’s the fetus,’ ” the shockingly candid Bush told NBC’s Matt Lauer, gesturing as if he were holding the jar during the TV chat, a DVD of which The Post exclusively obtained.

“There’s no question that affected me, a philosophy that we should respect life,” said the former president, who had to drive his distraught mother to the hospital at the time.

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“I never expected to see the remains of the fetus, which she had saved in a jar to bring to the hospital,” Bush writes in his new book, “Decision Points,” in an excerpt Lauer read during the interview.

“There was a human life, a little brother or sister,” Bush told the “Today” host during the sit-down to promote his tome, which hits stores tomorrow.

Bush said his mother gave him special permission to recount the private story in print.

But “the purpose of the story wasn’t to try show the evolution of a pro-life point of view,” Bush insisted to Lauer.

“It was really to show how my mom and I developed a relationship.”

During the interview, the former president refused to take a swipe at his successor, noting that President Obama “has plenty of critics — and I’m not going to be one.”

Addressing his own dismal popularity ratings when he left office, Bush said someone recently told him that his stature in the eyes of the American people was rising.

But he insisted that wasn’t important to him.

“If you chase popularity, you are chasing a moment. You are chasing a puff of air,” he told Lauer.

Bush stuck by his “very good” decision to choose political lightning rod Dick Cheney as his running mate.

The book and the interview reveal the anguish Bush felt after the 9/11 attacks less than a year into his first term.

He said his strength was renewed by the resolve of the American people, including workers in the World Trade Center rubble.

When he visited there, the men in hardhats called him “George” instead of “Mr. President.”

“And that was fine,” Bush said in the interview. “It was ‘George! Get ’em, George!’ I’m trying to be the comforter. These guys were looking at me like, ‘Are you going to go get these guys or not?’ ”

Bush said he was “deeply disappointed” that al Qaeda leader Osama bin Laden has yet to be captured — and has no regrets about using “water boarding” techniques to interrogate some of the terror master’s followers.

“We only used the technique on three people,” Bush said. “We gained valuable information to protect the country, and it was the right thing to do, as far as I’m concerned.”

Previous reports have said the technique was used on Khalid Sheik Mohammed, who planned the 9/11 attacks; Abu Zubaydah, a director of al Qaeda operations who was captured in Pakistan in 2002; and an unidentified prisoner.

Bush had nothing but praise for his father, who was president from 1989 to 1993.

“He never disappointed me,” Bush said. “He was always a great father.”

Additional reporting by S.A. Miller in D.C.

leonard.greene@nypost.com

