Rosie O'Donnell thinks about her children's birth mothers "every day".
The 60-year-old star has adopted kids Parker, 27, Chelsea, 25, Blake, 22, Vivienne, 19, and nine-year-old Dakota, and she thinks for someone to give up their child at birth is the "biggest act of generosity" a person can show.
She said: "I think about the birth mothers every day.
"I think about the generosity of human spirit that allows someone who knows they're not able at the moment to be a mom to this baby, give that baby all [they] deserve. To place that child in the loving arms of a stranger.
"It's the biggest act of generosity I think that humans can do. And I've been the benefactor of their selflessness and it made my life worth everything.
"Nothing in my life ever compares to the five kids and nothing, no reward you ever win, no amount of money you ever get, can replace the love of family, and of a parent and a child."
Rosie recalled how she was left in tears when her youngest child - who was diagnosed with autism when she was two years old - spoke to her birth mother for the first time when she was five years old.
She wrote in an essay for People magazine: "We're in contact, so Dakota gets on FaceTime and says, 'Are you the lady whose tummy I was in? I just wanted you to know I'm the kid that was in there, and when I got born, my mommy held me and I squeezed her pinkie, and I am with her. So I just want to let you know that's what happened to me. Bye.'
"I was in tears as was her birth mom. That's a pretty intense, complex, emotional thing for a little girl to put together."
The 'American Gigolo' actress hailed Dakota's autism as a "gift" because it has forced her to "see the world from a completely different place."
She said: "She's a gift from another dimension. The things she knows — about sea anemones and tide pools. I got to 60 not knowing about the Mariana Trench. Now I know all about it!
"Her ability to absorb information is unparalleled. I can imagine her winning on 'Jeopardy!' someday.
"She teaches me. To be able to see the world as she does — for me, it's been a wonderfully magical experience. I'm so glad we have each other."