Today, Abby and Erin Delaney are thriving, school-aged children living in North Carolina with their parents, Heather and Riley Delaney. After undergoing a groundbreaking 11-hour separation surgery at Children's Hospital of Philadelphia (CHOP) in 2017, the formerly craniopagus conjoined twins continue to reach impressive developmental milestones through ongoing physical therapy, speech therapy, and routine pediatric follow-up care.
Current Update: How Abby and Erin Delaney Are Doing Today
The story of Abby and Erin Delaney remains one of the most remarkable successes in modern pediatric neurosurgery. Separated when they were just 10 months old, the sisters are now growing up in a supportive home environment, attending school, and discovering their distinct individual personalities.
While both girls spent their infancy navigating significant surgical trauma and intensive care stays, their day-to-day life today looks much like that of other young children, augmented by specialized support therapies. Their mother, Heather Delaney, frequently shares updates regarding their developmental progress, emphasizing that while their recovery is a lifelong journey, each year brings new independence.
Individual Personalities and Developmental Progress
Although Abby and Erin shared a physical connection at birth, their personalities have developed uniquely:
- Erin Delaney: Known from an early age as the more physically decisive sister, Erin was the first to achieve major motor milestones post-surgery, including sitting up independently, crawling, and taking early assisted steps. She tends to be curious, vocal, and outgoing.
- Abby Delaney: Abby faced a slightly more complex immediate post-operative recovery due to the division of shared cranial blood vessels. However, she has demonstrated persistent determination in physical and speech therapy. She is often described as thoughtful, affectionate, and deeply attached to her sister and family.
Both girls attend school where tailored educational plans help them succeed academically and socially. They participate in standard childhood activities adapted to their physical development, supported by specialized equipment, adaptive footwear, and custom protective headwear when needed during active outdoor play or ongoing skull reconstruction phases.
Ongoing Medical Care and Therapies
Life today for the Delaney twins involves a structured schedule of medical maintenance and therapeutic interventions. Because craniopagus separation involves the division of bone, brain tissue, and major blood vessels, long-term pediatric management is required.
- Physical and Occupational Therapy: Regular sessions focus on fine motor skills, core balance, gait training, and hand-eye coordination.
- Speech and Language Therapy: Both girls work with speech-language pathologists to enhance expressive language skills, vocabulary, and vocal clarity.
- Pediatric Neurosurgery and Craniofacial Follow-ups: Periodic imaging (such as MRI and CT scans) monitors brain tissue growth, protective dura healing, and skull development.
- Cranioplasty Revisions: As the girls grow, pediatric plastic surgeons evaluate the need for minor reconstructive procedures or synthetic bone grafts to ensure their cranial vaults expand safely and symmetrically.
The Medical Background: Diagnosis and Early Life
The journey began during a routine 11-week prenatal ultrasound in 2016, when Heather and Riley Delaney learned they were expecting conjoined twins. The diagnosis was craniopagus conjointment, the rarest form of conjoined twinning, occurring in approximately 1 in 2.5 million live births. Craniopagus twins are joined at the skull, sharing skin, cranial bones, protective meningeal layers (dura mater), and often critical cerebral venous systems.
Transfer to Specialized Care
Upon receiving the diagnosis, the Delaney family connected with the Center for Fetal Diagnosis and Treatment at Children's Hospital of Philadelphia (CHOP). CHOP is one of the world's leading pediatric facilities specializing in complex twin separations.
Heather moved to Philadelphia late in her pregnancy to receive specialized prenatal monitoring at CHOP’s Garbose Family Special Delivery Unit, a dedicated facility allowing mothers carrying infants with complex fetal conditions to deliver steps away from specialized pediatric surgical suites.
Birth of Abby and Erin
On October 24, 2016, Abby and Erin Delaney were born via planned Cesarean section, approximately 10 weeks premature. Together, they weighed just 4 pounds, 13 ounces. Immediately following delivery, a multidisciplinary team of neonatologists, pediatric neurosurgeons, plastic surgeons, and specialized nurses stabilized the infants and transferred them to the Neonatal Intensive Care Unit (NICU).
- Prenatal Diagnosis: 11 Weeks
- Birth at CHOP: Oct 24, 2016
- NICU Care & 3D Surgical Planning: Oct 2016 – May 2017
- Historic Separation Surgery: June 6, 2017
During their first 10 months of life, the twins remained in the hospital. Medical teams focused on optimizing their nutrition, monitoring brain growth, and conducting advanced diagnostic imaging to plan their separation.
The Landmark June 2017 Separation Surgery
On June 6, 2017, at 10 months old, Abby and Erin underwent a complex 11-hour separation procedure. The operation required a multidisciplinary team of more than 30 medical professionals, including pediatric neurosurgeons, plastic and reconstructive surgeons, anesthesiologists, surgical nurses, and radiology specialists.
Key Surgical Challenges
The separation of craniopagus twins presents singular neurosurgical and craniofacial challenges:
- Shared Sagittal Sinus: The girls shared a major venous blood channel—the superior sagittal sinus—which drains blood from the brain back to the heart. Dividing this vessel required extreme precision to ensure adequate cerebral venous drainage for both infants to prevent stroke or hemorrhaging.
- Dural and Soft Tissue Reconstruction: Once the skull bones were divided, surgeons had to separate shared meninges (dura mater) without damaging underlying brain parenchyma.
- Scalp and Bone Coverage: A primary hurdle in total craniopagus separation is covering the large scalp defects left behind. Months prior to the main separation, surgeons implanted temporary skin expanders beneath the girls' scalp to gradually stretch the skin tissue, ensuring enough healthy skin was available to cover the open surgical sites once divided.
The Surgical Team Leadership
The historic surgery was co-led by two renowned CHOP specialists:
- Dr. Jesse Taylor: Surgical Director of the Craniofacial Program, who oversaw skin flap design, tissue expansion, and initial skull reconstruction.
- Dr. Gregory Heuer: Pediatric Neurosurgeon, who directed the delicate intracranial separation of brain membranes, cortical tissue, and shared blood vessels.
Using advanced 3D virtual surgical planning and custom printed anatomic models built from high-resolution MRI and CT scans, the surgical team mapped out every incision and vessel division weeks before entering the operating room. The procedure was successful, and after 11 hours, the girls were officially placed in separate operating suites for final scalp closure and cranial reconstruction.
Post-Surgical Recovery and Rehabilitation
Separation was only the first step in a multi-year rehabilitation journey. Following surgery, both girls spent several months in CHOP's Pediatric Intensive Care Unit (PICU) and step-down units before transitioning to inpatient rehabilitation.
Inpatient Rehabilitation Milestones
In the fall of 2017, the twins were transferred to CHOP’s Inpatient Rehabilitation Unit. Because their heads had been joined since birth, their neck muscles, core balance, and motor pathways required extensive retraining.
- Erin Delaney: Discharged first, in October 2017, after 485 days in the hospital.
- Abby Delaney: Discharged in November 2017, following additional monitoring for fluid management and cranial site healing.
Returning to their home state of North Carolina just before the holidays in late 2017 marked a milestone moment for the family, allowing them to establish a normal home environment while continuing outpatient physical therapy.
Milestones Timeline: 2016 to Present
The following timeline details the developmental journey of Abby and Erin Delaney from birth through their current status.
| Year | Stage / Age | Key Medical Events | Developmental Highlights |
|---|---|---|---|
| 2016 | Newborn (0–2 mos) | Born Oct 24 via C-section at CHOP; initial NICU stabilization. | Admitted to NICU; continuous monitoring of shared blood flow and vital signs. |
| 2017 | Infancy (10 mos) | Historic 11-hour separation surgery on June 6; initial reconstructive closures. | First time sleeping in separate cribs; discharge home to NC in fall 2017. |
| 2018 | Early Toddler (1–2 yrs) | Outpatient physical, speech, and occupational therapy routines; cranial checks. | Sitting independently, rolling over, improved head control, early vocalizations. |
| 2019 | Toddler (2–3 yrs) | Follow-up cranial imaging; fitting for custom protective remolding helmets. | Erin begins taking assisted steps; Abby develops strong crawling motor patterns. |
| 2020 | Preschool Age (3–4 yrs) | Elective minor scar revisions and ongoing craniofacial evaluations. | Improved expressive speech; interactive play between sisters; active preschool routines. |
| 2021–2022 | Early School Age (4–6 yrs) | Continuous speech therapy and gait training; developmental milestone tracks. | Entry into kindergarten; enhanced social engagement and independent movement. |
| 2023–2025 | Primary School (6–8 yrs) | Periodic neurosurgical progress reviews; routine cranioplasty growth checks. | Active school participation; continued motor skill refinement and individual hobby interests. |
| 2026 | Current (9+ yrs) | Long-term follow-up management; specialized orthopedic and neuro guidance. | Thriving in elementary school; advancing physical independence and strong sibling bond. |
The Science of Craniopagus Separation
Understanding the medical rarity of Abby and Erin Delaney requires examining the anatomical classifications of conjoined twins.
- Conjoined Twin Classifications
- Thoracopagus (Joined at chest - ~40%)
- Omphalopagus (Joined at abdomen - ~33%)
- Craniopagus (Joined at head - ~2–6%)
Craniopagus twins represent between 2% and 6% of all conjoined twin cases. They are further divided into two clinical categories:
- Partial Craniopagus: Twins share only outer skin and limited cranial bone, with separate dura, brain tissue, and venous systems. These cases carry a significantly higher rate of straightforward surgical success.
- Total Craniopagus: Twins share extensive bone, dura mater, cerebral cortical tissue, and major venous sinuses (as was the case with Abby and Erin). These procedures carry high risks of severe neurological deficit, venous infarction, or intraoperative hemorrhage.
Key Factors in Surgical Success at CHOP
Several clinical breakthroughs contributed to the successful outcome for the Delaney twins:
- Early Intervention Age: Performing separation around 10 months of age balances infant surgical resilience with neuroplasticity—the young brain's ability to reorganize and adapt following surgical alterations.
- Computer-Assisted 3D Modeling: Pre-operative 3D printing of the shared skull and vascular structures allowed surgeons to practice tissue division precise to the millimeter.
- Staged Tissue Expansion: Placing silicone expanders under the scalp prior to separation provided sufficient native skin to achieve tension-free primary coverage post-separation, drastically lowering infection risks.
Lessons for Families Navigating Complex Pediatric Care
The Delaney family’s ongoing journey offers valuable practical insights for families facing rare pediatric diagnoses or complex surgical recoveries:
1. Seek Multidisciplinary Medical Centers
Complex conditions like craniopagus conjointment require care teams that extend beyond pediatric surgery. Seeking care at major academic research institutions ensures access to specialized pediatric neurosurgeons, craniofacial plastic surgeons, neonatologists, and dedicated pediatric rehabilitation specialists.
2. Prioritize Early Intervention Therapies
Early physical, occupational, and speech-language therapies take advantage of early childhood neuroplasticity. Consistent outpatient therapy helps bridge developmental gaps caused by extended hospital stays or surgeries.
3. Coordinate Long-Term Pediatric Follow-Up
Children who undergo major neurosurgical procedures require structured long-term care plans. Parents should maintain coordinated records with:
- Pediatric neurologists and neurosurgeons (monitoring brain development).
- Craniofacial specialists (evaluating skull growth and skin integrity).
- Developmental pediatricians (assessing educational and cognitive support needs).
Frequently Asked Questions
Where are Abby and Erin Delaney today?
Abby and Erin Delaney live in North Carolina with their parents, Heather and Riley. They attend school and continue to make developmental progress supported by physical, occupational, and speech therapies.
When were the Delaney twins separated?
The twins were separated on June 6, 2017, at Children's Hospital of Philadelphia (CHOP) when they were 10 months old. The complex operation lasted approximately 11 hours.
Can Abby and Erin Delaney walk and talk independently?
Yes, both girls have made major strides in mobility and communication. While each girl progresses at her own pace and may use adaptive support or therapy assistance for complex movements, both communicate, interact socially, and participate actively in daily school and family life.
What kind of conjoined twins were Abby and Erin?
Abby and Erin were total craniopagus conjoined twins, meaning they were joined at the top of their heads and shared cranial bones, dura mater (the protective brain membrane), and key cerebral venous structures.
Who performed the separation surgery?
The operation was performed by a team of over 30 medical professionals at CHOP, co-led by Dr. Gregory Heuer (pediatric neurosurgeon) and Dr. Jesse Taylor (plastic and reconstructive surgeon).
Looking Ahead
The story of Abby and Erin Delaney remains a profound testament to medical innovation, family resilience, and dedicated pediatric care. From their prenatal diagnosis through their historic separation and ongoing childhood developments, the sisters continue to inspire patients, medical teams, and families worldwide. As they grow through their primary school years, their progress serves as a touchstone for advance planning and multidisciplinary care in pediatric neurosurgery.
