In 1976, Cole (D) had a vasectomy. His sperm count was measured as zero later that year. His wife (P) gave birth to a child in 1982. The couple separated in 1983, and P brought a paternity action against D for child support. There was a 95% chance that D was the child's father, based on a blood test. However, a doctor testified that D had been sterile since 1976, so there was little chance of him fathering a child. The trial court held that D was the child's father, based on the blood test. D appealed.