Abby can roll onto her stomach, hold up her head and flip the pages of her favorite story books. Her sister Erin can now sit up on her own, and she has started to think about crawling by holding herself up on her hands and knees.
At 10-months-old, twins Erin and Abby Delany are no longer fused at the top of their heads.
With a complex separation surgery at Children's Hospital of Philadelphia behind them, concerns for the twins hasn't ceased. They could be left with complications that could include neurological damage.
"Both girls had some brain bleeds happen while they were in surgery, Abby significantly more than Erin. So we are waiting to see exactly what that means," their mother, Heather, wrote on her blog a week after the procedure. "These days are scary. Yes, the girls got separated, but this is only the beginning."
The surgery that infants underwent was so rare that it has only been performed about 60 times worldwide since 1952 and never at the Children's Hospital of Philadelphia.
Conjoined Before Birth
When Heather had an ultrasound at 11 weeks of pregnancy, it was revealed that she was carrying conjoined twins.
"Riley and I already love our children more than we could possibly imagine, and that is what makes it so hard," she wrote in March 2016 after the ultrasound.
"We are choosing to believe that God has a plan for them, and it is to prosper them and give them hope and a future," she added.
Heather and Riley married in October 2015 and were overjoyed to learn that they were pregnant three months later. Even though Heather has younger identical twin sisters, she was surprised when she found out that she, herself was carrying twins.
"I mentioned to the doctor about how they seemed very close," she wrote on her blog. "That is when ... something that was 100 percent joy turned into almost 100 percent terror. He said very abruptly that he thought they might be conjoined."
Being attached by the head is particularly dangerous because if more than a little brain tissue is shared, the twins usually die during pregnancy or in the first few days after birth.
Soon after their early ultrasound, the couple began biweekly treks to Philadelphia from their North Carolina home for meetings with professional to help them along their journey.
"I have met with lots of doctors, social workers, psychologists, midwives, surgeons, and the list goes on," Heather blogged. "They make me feel almost normal. To have a place that makes me feel like I'm doing a good job is wonderful."
By 20 weeks of her pregnancy, Heather was moved into the hospital so she could be closely monitored. That was when it was discovered that Erin was the dominant twin, while Abby had signs of insufficent blood flow.
"It has gotten a little worse every time they have scanned," Heather wrote a year ago.
About a month later, the twins were delivered by cesarean section, about eight weeks premature. They each weighed 2 pounds and 1 ounce.
From here the babies steadily grew and started to reach developmental milestones.
Doctors began using 3D imaging to make models and create a plan for the surgery to separate them.
"Abby would be left with very little [of the sinus], meaning that Abby would have a much harder time and a much greater chance of death," Heather wrote. "When you are told that sort of information, your world stops."
"We know that children heal better and faster the younger they are, therefore our goal for Erin and Abby was separation as soon as possible with minimum number of surgeries," reconstructive surgeon, Dr. Jesse Taylor said.
Doctors originally came up with a plan for a multi-stage surgery, two weeks apart, which would allow shared blood flow to be rerouted and reduce complications.
That's when the plans changed.
Surgery To Separate
Six hours into the surgery, "our neurosurgeon came out and explained ... they got more than halfway and had no problems. Everything had gone well and the girls were doing so well," she wrote. "They decided it would be a better idea to continue."
Ten more hours passed and the anxious parents didn't get any more than vague updates on their babies.
Afterward, the neurosurgeon shared that Abby had narrowly survived the surgery.
"I could see the stress on his face," Heather wrote. "When they separated the sagittal, Abby started to bleed. They replaced her total blood volume between 10 and 15 times. He said he almost lost her several times but she kept hanging on."
There were 30 people involved in this complex surgery, that ended up taking 11-hours, was only the 24th of it's kind for the hospital.
Five months after their surgery, the girls are able to tackle life's milestones separately. Now being able to sit up on their own, roll over, craw and being carried separately in their parents's arms, they are thriving.
"The girls are doing well since being separated. Both have been in rehab for about a month now and are progressing more and more each day. We have tough times but we get through and we are bound to have more. But with God all things are possible and He has such a special plan for these girls and we love watching that plan unfold," they wrote on their Go Fund Me page a month ago.
Now at 15-months-old, the girls have spent their entire lives in the hospital until recently when Erin was discharged.
Abby still remains in hospital recovering. She still has some time before she is well enough to be discharged as well. "She has a little trouble managing her secretions so she can have a little trouble breathing sometimes, but it is getting better every day," Heather wrote.
They're hoping that she will be able to go home by the holidays. " We will hopefully be able to spend Thanksgiving and Christmas at home this year and we are beyond thrilled about it!" she wrote.
"Although this has been a long journey, with many ups and downs, Riley and I are thrilled to see how well the girls are doing today," Heather said. "We are so grateful for the Children's Hospital of Philadelphia team, and for the support and encouragement that our families, our friends and the community have given us during this long journey."