But he's not thought of it as a lifesaver.
Last year, however, that changed when a student in one of his biology classes privately inquired if he still had it.
Intrigued Tigchelaar said that he did and invited the young woman to his office for further conversation. There he asked why she was interested. She proceeded to tell him an amazing story, one that he now is sharing more widely as Christmas draws closer.
The young woman told Tigchelaar that a generation earlier her mother had been a student in one of Tigchelaar's biology classes. Unknown to Tigchelaar this student was three months pregnant on a day he had shown the class the fetus with its tiny fingers, facial features, eyes, outline of a liver and other human features.
"She had already visited a pregnancy center," Tigchelaar recalls the young woman telling him, "and was told about the 'product of conception' and 'contents of the uterus' that she had within her. She was advised to have an abortion and had one scheduled for the following morning."
But after Tigchelaar's class she realized she had more within her than a "product of conception." And she cancelled her scheduled abortion, continued with her pregnancy and eventually delivered a healthy baby girl.
"I am that girl," the student then informed a stunned Tigchelaar. "Thanks for my life."
Tigchelaar, at the time, was amazed, speechless. He remembers in a halting voice telling the girl simply that she was beautiful.
"Even now," he says, "I can barely tell the story without breaking up."
Yet tell it he is. And for an important reason.