Born in June 2023 in Ekiti State, Nigeria, twin sisters Mercy and Goodness entered the world as craniopagus twins—joined at the top of their heads with fused skulls, shared brain tissue, and interconnected blood vessels. This form of conjoined twinning is exceptionally rare, occurring in only about 5% of all conjoined twins and roughly once in every 2.5 million births. Many such pairs do not survive birth or the first day of life, making their survival to surgery a statistical rarity estimated at around one in 10 million.

At six months of age the girls were referred to the UK-based charity Gemini Untwined, which specialises in the research and surgical separation of craniopagus twins. Under the leadership of paediatric neurosurgeon Professor Noor ul Owase Jeelani of Great Ormond Street Hospital, an international team of more than 60 specialists from the United Kingdom, United Arab Emirates, Nigeria, Brazil and other countries began meticulous preparation.

Using advanced tools including artificial intelligence, 3D modelling, virtual reality and augmented reality, the team mapped every shared vessel and neural connection. The twins travelled to Sheikh Khalifa Medical City in Abu Dhabi for treatment. Over a period of several months they underwent four carefully staged operations that together totalled more than 40 hours in the operating theatre. The final separation procedure alone lasted approximately 12 hours. Custom 3D-printed titanium implants were later used to reconstruct the girls’ skulls.

The separation was successful. Mercy and Goodness made full recoveries, completed rehabilitation, and eventually returned home to Nigeria. Their case is described by the surgical team as a landmark achievement—the ninth successful craniopagus separation by Gemini Untwined and one of the most complex of its kind, enhanced by novel techniques that reduced trauma to the brain.

Today the sisters are growing independently, able to look at each other face-to-face for the first time. Their story stands as a testament both to the extraordinary resilience of the children and to the power of international collaboration, advanced technology and specialised paediatric neurosurgery.

Sources

• Gemini Untwined and Great Ormond Street Hospital statements
• Reporting by The National, The Times, ITV News, People, and related coverage of the 2025–2026 Abu Dhabi separation of Mercy and Goodness