Melissa Etheridge's partner pregnant with twins

Singer Melissa Etheridge (L) and her partner Tammy Lynn Michaels. Picture / Reuters

Tammy Lynn Michaels, partner of rocker Melissa Etheridge, is pregnant with twins.

"To answer the obvious question: We used an anonymous donor from a sperm bank," the couple said.

Etheridge has two children from her relationship with former partner Julie Cypher, who had the children through artificial insemination using a sperm donation from David Crosby.