Palin 'devastated' by daughter's pregnancy

NEW YORK, Nov. 14 (UPI) -- Former Alaska Gov. Sarah Palin says she and her husband were "devastated" when they learned their daughter Bristol was pregnant, ABC News reported Saturday.

In an interview with Barbara Walters, Palin said she did not realize their teenage daughter had been having sex with her boyfriend.

"That's why I was shocked," Palin said. "Truthfully, we were devastated."

The interview is to be broadcast in five parts with the full interview appearing on "20/20" Friday. The first segment airs on "Good Morning America" Tuesday, the day Palin's memoir, "Going Rogue: An American Life," appears in bookstores.

Bristol Palin, 18, was a high school senior when her pregnancy became national and international news a few days after her mother accepted the Republican vice presidential nomination last year. Her son, Tripp Johnston, was born in December.

Levi Johnston, Tripp's father, has given his version of life in the Palin household since his break-up with Bristol. In one interview, he said he was "pretty sure" Palin knew he and Bristol were carrying on an affair in the Alaska governor's mansion.