01/12/2007 AT 10:35 AM EST
Madonna got more than she bargained for when she adopted 1-year-old David from Malawi last year – but says she saw it as "saving a life."
"My social worker ... said, 'Good luck. You're going to be making it up as you go along,' " the pop star told David Letterman on his Late Show
Thursday. "She didn't say don't do it, but she just said expect challenges, and, boy, did we get them."
There was an outcry of opposition over the legalities of adopting from the country. (Madonna, 48, and her husband Guy Ritchie, 38, are still embroiled in the legal processes of adopting David.) Still, she said the controversy surprised her.
"We did everything by the book, and everything was kosher in terms of legal," she said. "But it brought a lot of attention to a country just coming to terms with the overwhelming number of orphans that are there. There are over a million orphans there ... and in my opinion the laws need to change because these children need to be rescued."
Recently Angelina Jolie complimented Madonna
for adopting David, but said she'd avoid adopting a child from a country where there is a limited legal framework.
As for how David is adjusting to being with the family: "He's a champion tantrum thrower," says Madonna, who joked with Letterman about having the same first name as her son. "By the way, do you like his name? King David, we call him."
The singer also weighed in on another major topic of conversation recently – underpants. "I've been hearing these stories – it's dreadful," she said referring to photos widely circulated of Britney Spears without underwear. "I love underpants."
Joked Letterman: "I remember one night here a long time ago, you brought me a pair of them, and I still have them." Madonna then quipped: "Maybe you could send them to Britney."
She said she's "pretty cut off" from many of the stories in the United States, "and so I come to New York and the first thing I hear is about people not wearing their underpants. What's going on? It's freezing outside!"