Kolkata: In a rare occurrence, a young mother in Kolkata has given birth to what is medically termed as the 'vanishing twin', a freak delivery in which one of the twins appears to be painted on a translucent leaf-like sheath.

The rare medical wonder, not reported in India till now, was witnessed by medicos last Friday (Sep 10, 2004) when 24-year-old Amita Dutta delivered twin babies, one healthy boy and another 'flat' lifeless form that looked more like a fossilised baby.

"This is really amazing. We had read about it in our medical books, but never heard anything like this being reported in the country," said Dr Swagata Mukherjee who assisted the normal delivery at the Howrah Jain Hospital.

The medicos had documented a twin after three months of Amita's pregnancy through pre-natal ultrasonography.

"However, at nine months, we could hear just one of the twin's heart-beat. That put us on alert," he said.

After the delivery, Mukherjee and Jayati Bardhan of the North Bank Diagnostic Centre scanned medical literature from across the world to find out that the occurrence, variously described as 'vanishing twin', 'twin embolisation syndrome' or foetus papiricus (leaf-like foetus), had not been reported from this part of the world.