Madonna was the mother of two biological children when she and her husband, British filmmaker Guy Ritchie, adopted baby David from an orphanage in a long and arduous process that has been widely criticized.
"It was painful and a big struggle and I didn't understand it," The Sun newspaper quoted Madonna as saying at a press conference at the Cannes Film Festival where her Malawi-themed documentary "I Am Because We Are" debuted.
"In the end I rationalized that when a woman goes through natural childbirth, she suffers an enormous amount. I went through my own kind of birthing pains -- dealing with the press on my doorstep, accusing me of kidnapping or whatever. But I had to go through some kind of process and in the end it made me stronger so I can't complain."
Madonna also said that, contrary to reports claiming otherwise, David's mother did die of AIDS and his father "absolutely agreed to the adoption."
"There is nothing controversial about the adoption. It is just there's a lot of bureaucracy and administration."