Steven Engelking argued that his wife, Amy, carried out the insemination without his knowledge. His ex-wife said he was involved in the decision and was the one who decided to have a second child using sperm from the same donor because he did not want his son to be an only child.
Engelking treated the children as his own during the marriage and after the couple separated, his wife said.
The appellate panel upheld a lower court ruling that both Steven and Amy Engelking are legally parents of their son and daughter.
"Assigning credibility is not our function, and we reject Father's invitation to do so," the court said. "The trial court's findings are supported by Mother's testimony, and the findings support the trial court's ultimate conclusion that each child was a child of marriage."