Raja

Stephanie Richmond / Courtesy of the St. Louis Zoo

The Asian elephant herd at the Saint Louis Zoo is about to grow again.

The Zoo announced today that Ellie is pregnant with a female calf. It's her fourth pregnancy and third birth - she miscarried in 2010 at 36 weeks. The typical elephant pregnancy lasts about 22 months, so Ellie's latest calf is due in the spring of 2013.

The Zoo says typical newborn elephants weigh between 250 and 350 pounds.