. giant panda Mei Xiang may be pregnant, a morning ultrasound indicates!
— Michelle Basch (@mbaschWTOP) They're watching Mei Xiang closely here (she's on the big center screen)
— Michelle Basch (@mbaschWTOP) You can't visit Mei Xiang (see her on the zoo's panda cam), but here's sleepy Tian Tian
— Michelle Basch (@mbaschWTOP) Shh!
— Michelle Basch (@mbaschWTOP) 
WASHINGTON 鈥� Bao Bao could be getting a baby brother or sister soon.
During an ultrasound Wednesday morning on the female giant panda Mei Xiang, veterinarians detected what they say could be a giant panda fetus, the National Zoo announced.
Based on the size of the fetus, about 4 centimeters, veterinarians estimated Mei Xiang聽could give birth early next week or in early September, though there is still 鈥渁 substantial possibility鈥� that she聽could resorb or miscarry the fetus.
. A DNA test would be needed to determine which of two pandas back in China sired the cub.
The zoo鈥檚 panda team has been monitoring Mei Xiang through the zoo鈥檚 panda cams.
Lately, zoo officials said, Mei Xiang has been spending more time in her den, body licking and sleeping in more, and cradling toys 鈥� all behaviors consistent with a pregnancy.
, a signal that she鈥檇 either have a cub or experience the end of a pseudopregnancy within 30 to 50 days.
鈥淭oday, we are cautiously optimistic,鈥� said Dennis Kelly, director of the National Zoo, in a news release. 鈥淲e want a healthy cub for all the right conservation reasons. I am excited, but I have to say that we were prepared for a cub even before this morning鈥檚 ultrasound. Our expert team of keepers, scientists and veterinarians are going to do exactly what they are trained to do and I鈥檒l just ask everyone to remain positive with us.鈥�
Zoo officials said part of the panda exhibit would聽be shut down until further notice to give Mei Xiang privacy, though the zoo鈥檚 panda cam will still be up and running.
Visitors can still see Mei Xiang鈥檚 cub Bao Bao, who turns 2 on Sunday, at outdoor enclosures and on the panda cams. Mei Xiang’s other cub,聽Tai Shan, was born July 9, 2005, and now lives in China.
Bao Bao was born Aug. 23, 2013 and is expected to go live in China when she turns 4.
