Twin boys who were conjoined at the tops of their heads have been separated by a team of surgeons in New York.
Thirteen-month-old Jadon and Anias McDonald underwent 16 hours of surgery, and are now undergoing additional procedures to rebuild their skulls.
On Friday morning, the boys' mother Nicole McDonald wrote on Facebook that she is excited but "aches with the uncertainty of the future".
She also posted a photo of Jadon alone in his own hospital bed.
"I actually asked why they rearranged the room because I hadn't really internalised the idea that there would be two beds in here," Mrs McDonald wrote with the photo, also wishing her son a "happy rebirth day".
In an earlier post, Nicole wrote: "It's a bit surreal to sit here and type this... I should feel so happy... TWO SEPARATE BABIES!!!...and yet I ache with the uncertainty of the future."
The boys were born with shared blood vessels and brain tissues, a very rare condition that occurs once in about 10 million births, doctors say.
Dr James Goodrich, who has performed similar operations for other children including two Syrian twins earlier this year, prepared for the operation by creating 3D models of the attached heads.
CNN's Sanjay Gupta, who witnessed the surgery, says that 80% of similar twins die if they have not been separated before the age of two.
The McDonald family moved house with their two-year-old son and twin boys from Chicago to New York to be closer to Montefiore hospital.
The family has raised more than $100,000 for the costs of surgery.