Oh baby, baby! Atlanta's zoo says its giant panda is expecting her second set of twins.
Zoo Atlanta said in a news release Tuesday that its veterinary team obtained an ultrasound image from Lun Lun confirming the presence of a second fetus.
Lun Lun, who turns 19 on Thursday, was artificially inseminated in March. Her pregnancy was confirmed Aug. 16.
The zoo says round-the-clock birth watch began Tuesday but there is no certainty of impending births as fetal resorption is not uncommon in giant pandas.
Lun Lun and male panda Yang Yang have five offspring, all resulting from artificial insemination.
The pair's first three cubs live at China's Chengdu Research Base of Giant Panda Breeding. Twins Mei Lun and Mei Huan were born in 2013 and live at Zoo Atlanta.