The actor's wife, London, gave birth to daughter Evie Elise Kress on Saturday (20Mar21), and they introduced her to fans on Instagram on Monday (22Mar21).
"And just like that, 3 became 4," the new dad captioned a series of snaps of the newborn. "Evie Elise Kress, born 3/20/21 at 5:31pm. 6 lbs, 4 ounces of light and life."
He added, "My wife is superhuman, and doing extremely well. My children are the greatest little gifts on the planet, and I still can't seem to stop crying."
Actress London, who also shares three-year-old girl Rosie with Nathan, also celebrated Evie's arrival on her Instagram page, and revealed she was conceived "straight out of us getting Covid," joking, "Guess we got restless after weeks of exhaustion,"
"You are the epitome of a Covid baby amidst the Covid baby boom," she wrote.
"Now, almost exactly one year since lockdown began, our lives have drastically changed again. But, our sweet one, this change has been one of hope and light. You have signified life to us, after so much life has tragically been taken. You have been a rainbow in the cloudy days of Covid, and a rainbow baby to us personally. Evie means 'Life', & Elise stems from a family name (including my middle name) that means 'God's promise.' "
"You are 'God's promise of life' to us, baby girl. You are a child of hope. We love you deeply, Evie Elise Kress."
The happy news comes five months after the couple announced its pregnancy, which had occurred after "multiple miscarriages."
The pair, which co-starred in 2014 thriller "Into the Storm", wed in 2015.