Women who experience high levels of stress are less likely to conceive children.  

Researchers at Ohio State University's Wexler Medical Center say women who have a high level of a known stress-indicating protein in their saliva are 29 percent less likely to become pregnant than other less-stressed women.  

Women are also more likely to be defined as infertile while levels of the protein remain high.  

Researchers say the study points to a need for women who want to become pregnant to use stress-reduction techniques to enhance their chances.  

The study appears in the journal "Human Reproduction."