Calls and e-mails to McConaughey's publicists weren't immediately returned early Tuesday.
The 38-year-old actor announced that Alves was pregnant in a posting on his Web site in January.
"Camila and I were side by side the entire time," McConaughey told the magazine. "We are both tired and elated, and are so happy to have created the greatest miracle in the world - having a child and making a family."
"Now comes the greatest adventure - raising one, together."
