Rebecca Herrick of Mosinee and her fiance, Shawn Lewer, said they were initially sent home from St. Clare's Hospital in Weston when they arrived Saturday because doctors said the baby was not ready to be born, WAOW-TV, Wausau, reported Wednesday.
However, the contractions became stronger a few hours later and the couple set off once again for the hospital, but this time they were slowed by a heavy fog.
"The contractions were getting stronger but it wasn't anything -- it didn't cross my mind that we wouldn't get to the hospital in time," Herrick said.
However, baby Elijah James was soon born in the passenger seat while the van was still in motion.
"I just kept going," Lewer said. "I knew I had to get her here so that's what I did."
"He was born at that point in the passenger seat of the van," he said. "The front passenger seat. She was kind of not sure what to do, so I told her to put him upside down and pat him on his back to make sure that he's breathing."
The mother and new baby were discharged from the hospital Tuesday.
"He's perfect," Herrick said. "He is."