Tennessee ? One of the Memphis Zoo’s young pandas is pregnant, officials said an ultrasound test confirmed Wednesday.

The giant panda Ya Ya, on loan from China, was artificially inseminated in January after she and a male companion failed at mating.

“I’m excited, but I’m also cautious because we have a long way to go before the birth,” said Chuck Brady, the zoo’s president.

Zoo spokeswoman Julie Dodson said Ya Ya is expected to give birth in the next 30 to 45 days, and the zoo will do weekly ultrasounds to monitor the health and growth of the fetus.

Zoo staff now monitors Ya Ya 24 hours a day. She is in her maternity den and has access to her dayroom, which is on exhibit for zoo visitors.

As the birth approaches, Ya Ya will likely spend a lot more time alone and settle into the tree in her maternity den, zoo officials said. The tree, which is equipped with an infrared camera, is a replica of where a giant panda would give birth in the wild.

The zoo had been closely monitoring her for weeks as the potential due date drew near for the 6-year-old panda. Male 8-year-old Le Le also is on loan from China.

Panda pregnancies cannot be confirmed until shortly before the delivery date, but zoo officials have been monitoring Ya Ya continuously this month to watch for behavioral changes such as pacing, agitation and becoming more secluded.

Pandas are notoriously poor breeders – one reason their species is endangered – and females have only three days a year in which they can conceive.

Only three other U.S. zoos – San Diego, Washington and Atlanta – have giant pandas. The most recent panda cub born in the U.S. was Mei Lan in Atlanta last September.