Arquette and Cox split in October 2010 after 11 years of marriage and got officially divorced in May this year.
The former "Friends" actress was shocked when she got the news of Arquette's new baby, said a source.
Cox, who has a nine-year-old daughter, Coco, with Arquette, is allegedly worried he is drinking too much to cope with the pressures of a newborn.
"Courteney was shocked when she learned Christina is pregnant - because he is clearly still dealing with a host of issues related to his addiction recovery. She is having a hard time finding anything positive to say about David's decision to have more children," a source told radaronline.com.
Arquette, 42, checked into rehab in January 2011 to be treated for alcoholism, but he resumed drinking this summer.
"Although they are divorced, Cox will never stop caring about David - especially now that he is going to give Coco a half-sibling," added the source.
--IANS (Posted on 29-11-2013)