The actress - who plays Gabrielle Solis in the hit U.S. TV show - is said to be determined to found a family with her husband, basketball player Tony Parker.
Marc says Us Weekly magazine: "Eva Longoria is trying desperately to get pregnant with Tony. After their telephone their doctor, she promised me I will be the next call!"
The new 'Desperate Housewives' Eva series gives the opportunity to practice her mothering skills.
Together five years in the future, Eva Longoria character is now a mother of two children.
Marc added: "Gaby is a very hard time, the mother of two overweight, hyperactive children. But Eva has a wonderful time playing her! "
Eva Longoria previously revealed Marc has banned all pregnancies on the board after his co-star Marcia Cross conceived twins and pregnancy has been written in the script.
She said: "You know when Marcia Cross was pregnant? Marc Cherry came on the board and he was like, 'No more pregnancies this year! They are much more difficult to write a book!"