Samuel David Cheney was born at 9:46 a.m. on Wednesday at Sibley Hospital in Washington, D.C., ABC News reports. He weighed 8 lbs., 6 oz. He is the first child for Cheney, 38, and her partner, Heather Poe, 46.
"The vice president is pleased to be a grandfather for the sixth time," spokeswoman Megan McGinn said.
Dick Cheney revealed last month that the baby would be a boy. "I'm delighted I'm about to be a grandparent for the sixth time," he told ABC News Radio. "I'm looking forward to the arrival of a new grandson."
Cheney's press secretary confirmed in December that the couple were expecting; later that month, President Bush, who opposes gay marriage, told PEOPLE: "I think Mary is going to be a loving soul to her child. And I'm happy for her."