The only sperm bank in Shanghai is preparing to move to larger premises that will provide a better storage for frozen sperm, a bank staff member has said.

"The reproductive medicine center will have three floors with a total area of 1,000 square meters for the sperm bank, making its floor space sevenfold that of what it used to be," said Du Hongwei, assistant to the bank's supervisor.

According to Du, the new sperm bank will be located in a reproductive medicine center in Pudong New Area, which is usually known as the northern branch of Renji Hospital.

Since 2003, the bank has provided 23 medical institutions in China with more than 30,000 frozen semen samples, helping about 4,000 women to fall pregnant. The new sperm bank is expected to store far more than the present 100,000 semen samples with its bigger space.

Despite the increasing demand for sperm due to environmental and genetic reasons, donations are difficult to come by.

"Shanghai's sperm bank is able to meet local needs, but we are still expecting more donations," Du said.