For a group of four women, family reunions are a big yearly event.
At least once each year, Marianne, Emily, Meredyth Capasso and Dana come together with their kids to catch up and spend time with one another.
And while family reunions are always special, the annual event for these four women tells the tale of how they're connected because they were once strangers.
In a story first reported in Glamour by contributor Joseph V. Amodio, Marianne, Emily, Meredyth and Dana’s special bond came together after the same sperm donor fathered their children.
Amodio said he first found out about the story after a friend put him in touch with Meredyth, who was trying to find her daughter's donor siblings.
"What I found fascinating is that she started out doing this for her daughter," Amodio told "Good Morning America." "But what she wound up finding was this ad hoc sisterhood that she never knew she needed."
The four women ended up finding each other on the Donor Sibling Registry (DSR), a site where you can volunteer to connect with others who share the same donor, and Marianne was the first to reach out, initiating all four families to slowly connect over the years.
"I wanted my kids to always know their family," said Marianne. "Family has always been the most important thing to me."
Meredyth, who wanted to be transparent with her daughter about her donor said, "I thought it was really important that this not be something scary or foreign to Gabi, that it be just part of her story."
Before the four met in person, Emily sent a photo of her daughter, Laurel, and it was the shock of a lifetime when Meredyth saw how strikingly similar she looked to her own daughter, Gabi.
"I thought someone was playing a joke on me," said Meredyth.
Emily added, "I wasn't really looking for a connection until I saw the photo. And then I realized that I could pretend all I wanted, it wasn't really about me. It was really about them."
In 2014, Marianne, Emily, Meredyth and Dana came together for the first time to have all their kids meet.
"It was just this kind of heartstring pull because you could see your kid in those faces. It was just wild," Dana said.
Now, with their story, they're shedding light on donor siblings and opening up a larger conversation about what it means to be a modern family today.
"We all love our kid," said Emily. "And then it was like, oh, there was more to love."