Feb. 7 (UPI) -- Kellan Lutz and his wife, Brittany Lutz, are feeling heartbroken in the wake of a miscarriage.
The 34-year-old actor and Brittany Lutz mourned their unborn baby girl Thursday on Instagram after experiencing a miscarriage six months into Brittany Lutz's pregnancy.
Brittany Lutz shared the news alongside an older photo of herself cradling her baby bump.
"Baby girl, 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," Brittany Lutz wrote. "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."
"I'm not ready to talk about what happened, and I'm not sure I ever will. But I can say I am SO grateful for the most amazing husband who's been by my side the entire time," she said. "I have the best most supportive family. The prayers from friends have meant everything."
Brittany Lutz alluded to life-threatening complications while thanking her team at UCLA Medical Center.
"My incredible doctor and the amazing team of UCLA Medical Center who kept me alive are the real MVPs. And to all of you who donate blood- I have never been more grateful to you. Without you people like me wouldn't be here."
Lutz re-posted his wife's message on his own account, calling her his "Wonder Woman."
"It's been a crazy rollercoaster of a week with a lot of emotions," the actor wrote. "Taking heartbrokenness to a whole new level but Grateful for these past 6 months and the journey itself."
"I love you @brittanylynnlutz," he said before thanking fans. "Thank you for all your love, respect in this private time, understanding of this situation, and utmost support!"
Lutz's Twilight co-stars Nikki Reed, Ashley Greene and Peter Facinelli were among those to voice their support for the couple in the comments.
"I'm so so sorry Kel. Our love and hugs are wrapped around both of you during this unimaginable time... we love you," Reed wrote.
"I am so sorry to hear this Kel. I'm inspired by your and Brittany's strength. My heart and prayers are with you guys," Greene added.
"Sending all my love brother. There are no words that can help make it better. Only time," Facinelli said.
Lutz had announced Brittany Lutz's pregnancy on Thanksgiving in November. The couple married in 2017.
Lutz played Emmett Cullen in the Twilight film series. He most recently appeared in the movie What Men Want, starring Taraji P. Henson and Tracy Morgan.