updated 07/08/2011 AT 9:00 AM ET
•originally published 07/07/2011 AT 6:00 PM ET
Three years into her captivity, Jaycee Dugard went into labor with her first child – a frightening experience compounded by the fact that she didn’t understand what was happening to her.
“I didn’t know I was in labor,” Dugard, now 31, tells ABC News’s Diane Sawyer in an exclusive, two-hour interview to air on Sunday’s Primetime. “I was still locked [in] at the time. Just scared.”
In addition to the Sawyer interview, she has published a detailed story of her ordeal, the book A Stolen Life, excerpts from which appear exclusively in this week’s PEOPLE.