A Republican congressman vying to unseat Democratic Sen. Mary LandrieuMary LandrieuCNN producer on new O'Keefe video: Voters are 'stupid,' Trump is 'crazy' CNN's Van Jones: O'Keefe Russia 'nothingburger' video 'a hoax' Trump posts O'Keefe videos on Instagram MORE announced Thursday that his unmarried teen daughter is pregnant, according to multiple reports.

"Earlier this year, Laura and I learned we will become grandparents this summer," Rep. Bill Cassidy, a medical doctor from Baton Rouge, said in a statement to NOLA.com/The Times-Picayune late Thursday.

"Our children have been the greatest blessing of our lives and we welcome our grandchild as a joyous addition to our family," he continued. "Our daughter now faces a more challenging future than her peers. She has our unconditional love and support."

The announcement comes as Cassidy is considered the GOP leading contender challenging Landrieu in a closely-watched midterm race.

Landrieu is one of the most vulnerable Democrats running for reelection.

Cassidy's daughter is a rising senior at a high school in Baton Rouge.