The babies were about to undergo a skin-stretching surgery, the first step in their eventual separation at Texas Children's Hospital in Houston. They share a chest wall, diaphragm, intestines, lungs, lining of the heart and pelvis.
Five hours later, it was over.
In recovery, the Mata family leaned over groggy Knatalye and Adeline, smoothing their hair back and kissing them in the recovery room.
"We are so thankful for the support and thoughts and prayers for our girls as they continue to grow, recover and prepare for the next step in their journey," Mata said in a statement.
The twins will spend the next six to eight weeks recovering as a team of surgeons spanning six departments plans their separation, which is expected to take place early next year.