See why this time-lapse video of a woman's full-term pregnancy with twins is going viral.
twins pregnancy video
Credit: Heather Tomoyasu/YouTube

A time-lapse video of a twins pregnancy progression is going viral, racking up more than 128,000 views since it was shared by mom Heather Tomoyasu in October. Once you watch it, you'll understand why so many people have found it so fascinating.

In the unforgettable clip, we first see an adorable family of three: a mom, dad, and self-professed "only child"—a title, they revealed, was set to expire in just a few months. As the video progresses, we see Tomoyasu's tummy growing during her pregnancy, while her toddler son stands on a stool beside her, alternately feeling on her belly and giving her sweet hugs.

The belly becomes bigger and bigger, and the soon-to-be not only child is seen kissing the belly, as mom beams down at him.

Then dad is back for a sweet gender reveal using balloons: It's twin girls!

Watching via time-lapse video how a woman's body changes throughout her pregnancy is truly fascinating. That Tomoyasu wears the same black sports bra and spandex shorts throughout the video makes the progression even more incredible to witness.

Toward the end of the video, this soon-to-be mom-of-three is starting to look rather big, and uncomfortable. When will the twins be here?!

Oh, she's leaving, saying goodbye to her little boy. Is she ready to deliver the girls?

Yup! There they are, newborn babies making their cameo at the end of the 2-minute video. The new family-of-five beams as mom and dad alternately hold the babies and hug their son.

Congratulations to the Tomoyasus on their beautiful family, and thanks for sharing this incredible video that showcases the wonder of a woman's body during a twins pregnancy.

Melissa Willets is a writer/blogger and a mom. Follow her on Twitter (@Spitupnsuburbs), where she chronicles her love of exercising and drinking coffee, but never simultaneously.