The gunmen, who have not been identified, burst into the house in Colerain Township, outside Cincinnati, on Saturday evening, not long after the pregnant woman revealed she would soon give birth to a boy, according to the Cincinnati Inquirer.
The woman was shot in the thigh and was receiving treatment for her injuries, the paper said, citing local police.
Another woman at the party was killed, the newspaper reported, and eight people were injured, one of them seriously, the newspaper said. The victims were not identified.
Witnesses told police they saw the two gunmen run out before driving away in a car.