Lun-Lun, a 15-year old giant panda who lives at Zoo Atlanta, is pregnant with what will be the first panda cub of 2013 in the U.S.

Lun-Lun is already mom to three males with fellow panda Yang Yang, but all of her cubs were the product of artificial insemination. One of her cubs, 6-year old Mei Lan, resides at a research center in China. Dr. Copper Aitken-Palmer assisted in the most recent insemination, and scientists are eagerly awaiting the birth, which is due in about two weeks.

“We’re thrilled about the possibility of a fourth cub for Lun Lun, but we remain cautiously optimistic at this point,” Zoo Atlanta’s president, Raymond B. King, said. “Giant panda cubs are extremely fragile, and the chance remains that the fetus does not go to term. 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.”

Given Lun-Lun’s previous successful pregnancies, zoo officials are hopeful that she’ll carry this cub to term. Her other cubs were each the only giant pandas to be born in the U.S. in their respective years.

Image: Zoo Atlanta