"Max and I are having another miscarriage. Last week I went in for an ultrasound, almost nine weeks along and no heartbeat, again.
"This would be our fourth time now but the first time sharing about it," she added.
Hanneman, who moved from New Zealand to Hawaii at the age of 17, says it "never felt like the right time" before to talk about her previous miscarriages, but now wants to be more open about the struggles her family is facing.
"I know I'm not alone in this. I am so sorry to all who have to go through this to," she continued.
"I truly want anyone else going through the same to feel seen and acknowledged and feel SO loved, important and valued with so much purpose in life.
"It's not easy, it really sucks! Especially when we still don't have answers. But we are getting through it and am grateful to know it's in the Lord's hands, and I find comfort and peace in that. I know rainbows come after the rain," she added.
Hannemann and husband Max have two children - Roca, 7, and Elko, 2.
Her candid post touched many of her 271,000 followers who expressed sympathy for her grief and also their own stories of pregnancy loss.
"I'm so sorry for your losses, it's an unbearable pain. I also had three miscarriages many years ago, and then went on to have two lovely children," one person wrote.
Other followers also praised the Kiwi-born mum for speaking up about her grief.
"When I went through a stillbirth and then a miscarriage, the thing that helped me the most was to know that I wasn't alone," someone else said.
