The 58-year-old actor and his wife, Gina Cirone, welcomed a boy and a girl via surrogate on July 5 in Los Angeles. Born premature, "the babies are doing great and are improving every day. We can't wait for them to come home," they tell Us in a statement.
Petersen and Cirone tied the knot in July 2003. The twins join half-sister Maite, 36, from the actor's seven-year marriage to Joanne Brady. Maite gave birth to sons Mazrik in October 2003 and Indigo in August 2009.