WASHINGTON—South Dakota Rep. Stephanie Herseth Sandlin is expecting her first child in late December.

In an e-mail to friends and supporters, Herseth Sandlin and her husband, former Texas Rep. Max Sandlin, said they were overjoyed to share the news. She said they are looking forward to a “particularly blessed holiday.”

Spokesman Russ Levsen confirmed the news, saying the pregnancy will not affect Herseth Sandlin’s re-election this year. He said the late December due date works well with the congressional schedule, since Congress is not expected to be in session at that time.