The Children's Hospital of Fudan University will carry out surgery on conjoined twin girls with the help of 3D printing technology, which is the first case of such surgery in China, China's News Service (CNS) reported Sunday. 

The surgical operation will be performed on June 9 at the hospital affiliated to Fudan University in Shanghai.

The twins were born in Ganzhou city, southeastern China's Jiangxi Province on March 17, 2015.　　

Since the year of 2000, the hospital has successfully separated six sets of conjoined twins, including four sets of symmetrical conjoined twins and two sets of asymmetric conjoined twins. Of them, a set of twins is connected at the chest and stomach with abnormal formation of the heart, according to the CNS reports. The twin baby girls conjoined at hip is a new challenge to the hospital.

Zheng Shan, vice president of Fudan University, said conjoined twins is a very rare congenital malformation, with the incidence rate ranging from 1 in 50,000 to 1 in 200,000 and male and female ratio being 1 to 3. The vast majority of Siamese twins are conjoined at chest and abdomen. Twins conjoined at hip is rare in the world, accounting for about 18 percent of conjoined babies.