The actor shared the sad news on social media on Thursday (February 06), revealing his wife was six months along when she lost their first child, a daughter.
Calling Brittany "Wonder Woman", Lutz said it has been a "crazy rollercoaster of a week with a lot of emotions".
"Taking heartbrokenness to a whole new level but Grateful for these past 6 months and the journey itself," he wrote alongside a black-and-white photograph of his spouse showing off her baby bump. "In life we might not get the answers to all of our questions but we will always remain fairthful! (sic) God will restore. I love you @brittanylynnlutz."
"Thank you all for all your love, respect in this private time, understanding of this situation, and utmost support! Just know we love you all and appreciate you all and we process all differently. Can't wait to see our baby girl in Heaven when God calls us home."
Brittany added: "It was my absolute honor and pleasure to be your mom these last 6 months. I did my best and it was an absolute joy seeing your little face all those times on that screen and feeling your tiny kicks."
"I don't know why it happened the way it did, but part of me finds so much peace knowing you never experienced pain or heartache and never will. You're in the arms of Jesus now and one day we will get to meet you for real. Until I see you in heaven... your mommy loves you so much."
She also heaped praise on "The Legend of Hercules" star, calling him "the most amazing husband".