Edinburgh Zoo's Giant Panda Tian Tian No Longer Pregnant

Edinburgh Zoo's female giant panda, Tian Tian, is no longer pregnant, according to zoo officials.

Chris West, the zoo's chief executive, said all evidence suggested Tian Tian conceived and carried a fetus to late term.

"We are all saddened by this turn of events after so many weeks of waiting," he told reporters. "Timings are difficult to pinpoint at this moment, but we had a meeting this morning where Tian Tian's behavior and hormone results were reviewed and have come to the conclusion that it is very likely she has lost the pregnancy."

The panda was artificially inseminated April 22 by sperm from two donors after she and Yan Guang, a now dead male from Berlin zoo, failed to mate naturally, The Guardian reports.

According to West, Tian Tian had passed a "mucus plug," began producing a pre-birth breast milk and had a "prolonged secondary rise" in progesterone, the UK news outlet reported. It became apparent that she was no longer pregnant, however, when the panda reverted back to normal eating and behavioral patterns.

"Such a loss has always been in our minds as a very real possibility, as it occurs in giant pandas as well as many other animals, including humans," West said. "Our dedicated team of keepers, veterinary staff and many others worked tirelessly to ensure Tian Tian received the best care possible, which included remote observation and closing the panda enclosure to visitors to give her quiet and privacy."

Success has been had elsewhere, however, including the Smithsonian's National Zoo in Washington where a female giant panda cub was born in August after being conceived through artificial insemination. Shortly before that, the first set of panda twins born in the United States in 26 years arrived at Zoo Atlanta.

According to West: "New hormone research is beginning to indicate that lost pregnancies are more common in giant pandas than first thought, though at the moment no-one knows why."