Previously conjoined twins Allison and Amelia make their public debut

Shellie Tucker (holding Allison), Greg Tucker (holding Amelia) and their 2 1/2-year-old son Owen poses with some of the twin's doctors at a press conference about the twin's successful separation on Dec. 20, 2012. / The Children's Hospital of Philadelphia

Recently separated conjoined twin girls Allison June and Amelia Lee Tucker had their first public appearance at the Children's Hospital of Philadelphia on Thursday.

13 Photos

Conjoined twins: Allison and Amelia

The 10-month-old girls had been joined at the lower chest and abdomen in a condition known as an omphalopagus connection. They shared a chest wall, diaphragm, pericardium and liver before the surgery. Allison was discharged on on Dec. 17, but Amelia will require a longer stay into the new year.

"Both Allison and Amelia are doing well, and we expect them both to enjoy full, healthy and independent lives," Dr. Holly L. Hedrick, the pediatric general, thoracic and fetal surgeon who led the Children's Hospital of Philadelphia surgical team, said in a press release.

The two sisters underwent the separation surgery when they were 8 months old on Nov. 7. About 40 medical professionals assisted in the seven-hour procedure. They were the 21st pair of twins to be separated at the hospital.

Prior to the surgery, the girls had spent their whole lives at the hospital. For their first seven weeks, they lived at the Harriet and Ronald Lassin Newborn/Infant Intensive Care Unit (N/IICU) and then moved to a surgical step-down unit.

Months before the separation, plastic surgeron Dr. David Low put skin expanders in both girls to increase their skin surface so they could cover the areas that would be left open after the surgery.

"Like all separations of conjoined twins, this was a very complex surgery, but it went very well and as expected," Hedrick said in a press release at the time.

• Conjoined twin girls successfully separated in Philly

Most scientists believe that conjoined twins occur when one fertilized egg divides into two fetuses but does not separate, according to the Mayo Clinic. Identical twins become connected, with how far the egg splits being the determining factor of where the connection will be.

According to the University of Maryland Medical Center, conjoined twins make up one out of every 200,000 live births. Only 5 to 25 percent of conjoined twins survive, with 40 to 60 percent of conjoined twins born stillborn and 35 percent living for only one day. Females make up 70 percent of conjoined twins, and are three times more likely to be born alive than their males.

To learn more about Allison and Amelia's journey, watch the video below:

[godidlove]

The parents' decision was great.

Next, it will be greater if the scientists can figure out the cause of such co-join, and find means to prevent it.

The doctors in this case deserves appreciation.

[earlysaid]

These are two beautiful little girls. It is so good that they were seperated and that it went well so that they will live good lives. I wish them all the best. They are pretty.

[travelers345]

The video says they shared the same sternum. I wonder how they separated them at the sternum, whether they split the sternum into two separate sternums vertically down the middle or whether they gave the entire sternum to one child and some sort of sternum substitute to the other child.

[sayl2012]

Hard to tell, but whatever they did, it was successful!!