Veterinary staff said they have only been able to ultrasound one side of Kiki's stomach, so they don't know if she will have more that one cub.
"We used a specially designed bench to perform the ultrasounds on Kiki," said Nicole Presley, curator at Fresno Chaffee Zoo. "When Kiki is positioned correctly on the bench, one person is able to feed her while another person can safely position themselves under her and use the ultrasound probe to get an image."
On average, lionesses give birth to litters consisting of two to four cubs. At this time, the Zoo is unable to confirm how many cubs Kiki is expecting.
The zoo said because she is pregnant, she may not be on exhibit at all times.
Kiki, 12, came to Fresno in June 2015 from Zoo Atlanta along with her daughter, Zamaya, 2. This will be her third litter of cubs. Her first litter was born in 2008, followed by a second litter in 2013.
Chisulo, the father, is two-years-old and came to Fresno in November 2015 from the Smithsonian's National Zoo in Washington. This will be the first litter of cubs for Chisulo.