Asked what types of clothing he designs for celebrities, the fashion designer told People magazine: "Well Jennifer Lopez, at this moment, she requests something very special because she is waiting for the baby."
"It is so complicated because every week she is getting bigger," Cavalli said in a story posted Tuesday on the magazine's Web site.
Cavalli, known for his attention-getting designs, created free-flowing outfits for Lopez, who has been on tour with her husband, Marc Anthony.
Cavalli's comment came after weeks of speculation, tabloid baby-bump pictures and raised eyebrows. Lopez, 39, has declined comment.
A telephone message left Wednesday for her publicist, Nancy Ryder, was not immediately returned.
"The thing about Jennifer Lopez, she is a singer, she is a dancer," Cavalli said. "Most of the time when I prepare something for the tour, the performer, they want something very soft so they can dance and so they can move free."