"It was painful, and it was a big struggle, and I didn't understand it," the 49-year-old singer told reporters at the Cannes Film Festival on Thursday, where her documentary, "I Am Because We Are," which shows poverty, AIDS and other diseases devastating Malawi's children, was being shown.
"But in the end, I rationalized that when a woman has a child and goes through natural childbirth, she suffers an enormous amount," she said. "So I sort of went through my own kind of birthing pains with dealing with the press on my front doorstep accusing me of kidnapping or whatever you want to call it."
Madonna and her husband, Guy Ritchie, have been raising David Banda, now 2, since 2006. The singer met David while she was establishing charity projects in the southern African nation.
The couple have a 7-year-old son, Rocco, and Madonna has an 11-year-old daughter, Lourdes.
Critics have said she used her celebrity status to circumvent Malawian adoption laws -- allegations she denies. Regulations only stipulate that prospective parents undergo an 18- to 24-month assessment period in Malawi, a rule that was bent when Madonna was allowed to take David to London.
The adoption still must be approved, and a judge in Malawi was expected to issue his ruling next week.
Madonna said she was "happy to be the guinea pig" for Malawian adoptions.
"Hopefully, after we get through this adoption, it will be easier for people to adopt children," she said.
Madonna was at Cannes to show her documentary, which she produced and narrated, and to attend a gala benefit dinner for the American Foundation for AIDS Research. The film was screened outside the official festival.
"I Am Because We Are" was directed by Nathan Rissman, a first-time filmmaker who has worked for Madonna as a gardener and a caregiver for her children.
"He's a great nanny," she said.
"It's `manny,"' Rissman joked.
Rissman said Madonna "loves to give people opportunities" and that he always tried to do his best at whatever task he was assigned.
"And I noticed," she said.