'The Challenge' star Abram Boise and pregnant wife open up about 'vanishing twin'

MTV's "The Challenge" star Abram Boise and his wife, Rachel Missie Boise, recently shared with fans that she's pregnant with their first child. But the pregnancy hasn't been what they were expecting.

In an Instagram post on Sunday, Missie Boise explained that the couple experienced what's called a vanishing twin.

"My husband and I are so excited to announce we’re expecting our first child!" the mom-to-be wrote alongside a photo of herself and Boise, 37, exchanging a kiss as she holds up a sonogram. "This pregnancy started out as twins however within the first trimester my body decided it could only support one baby."

"We experienced what’s called 'vanishing twin,'" she continued. "The body sacrifices and reabsorbs the other fetus into the uterine wall, putting all that nourishment towards the strongest baby. We had gotten so attached to the idea of twins and mourned the loss of what could have been."

"Now we continue to celebrate what is, the beautiful life growing healthy and strong," Missie Boise concluded. "Our bodies are so dedicated towards protecting, and making decisions towards the greater good. Remember to be gentle, take care, and love yourself as your body chooses to love you."

Vanishing twin syndrome usually occurs within the first trimester of pregnancy. They're more commonly reported now than in previous years thanks to advancements in ultrasound technology, which can detect multiple pregnancies earlier than ever, according to WhatToExpect.com.

Vanishing twins are thought to occur in 20 to 30% of pregnancies, and often the mother doesn't experience any symptoms. In fact, she usually goes on to have a normal pregnancy and deliver the single baby without complications, according to What To Expect.

A mom who lost one of her twins during pregnancy several years ago, Maura Deptula of Chicago, previously told TODAY that the experience left her "struck by how powerful my sadness was and how it lived alongside my great hope and joy."

"I had people close to me say things like everything you went through was worth it because you now have this beautiful baby,” she recalled to TODAY. “And it will be easier for you to have only one, in the end, you’ll be happier.”

A vanishing twin left another mom, Julie Cook, a writer for the Daily Telegraph, wondering about the good and bad of early stage ultrasounds.

"Scans have enormous benefits, but do they also have a downside?" she wrote in a blog post a few years back. "Greater technology means greater awareness. But ignorance can sometimes be bliss."