Giant panda at Atlanta zoo expecting her 4th cub

An ultrasound has confirmed that a giant panda at Atlanta's zoo is pregnant with her fourth cub and will likely give birth later this month, zoo officials said Tuesday.

Veterinarians at the zoo estimate 15-year-old Lun Lun will deliver a cub in two to three weeks, Zoo Atlanta officials said in a news release. An ultrasound done Sunday shows the fetus is currently 1.08 centimeters long. Veterinarians based their birth window estimate on a similar ultrasound from Lun Lun's last pregnancy in 2010.

The cub would be the first giant panda born in the U.S. this year.

"We're thrilled about the possibility of a fourth cub for Lun Lun, but we remain cautiously optimistic at this point. Giant panda cubs are extremely fragile, and the chance remains that the fetus does not go to term," zoo president and CEO Raymond B. King said. "A birth would be another success for our giant panda program, and we share our optimism with our fellow U.S. zoos housing this iconic species and with our colleagues at the Chengdu Research Base of Giant Panda Breeding in China."

Pandas sometimes act pregnant even when they are not, but the ultrasound has confirmed that Lun Lun is pregnant. Hormone tests done by Dr. Dave Kersey, an expert in giant panda endocrinology from Western University of Health Sciences, will allow the veterinary team to continue to monitor her condition.

Lun Lun was artificially inseminated in March. She and her 15-year-old mate Yang Yang have three previous offspring, also through artificial insemination: 6-year-old male Mei Lan, who now lives at the Chengdu Research Base of Giant Panda Breeding; 4-year-old male Xi Lan; and 2-year-old male Po.

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