Mark Feinberg, a Pennsylvania State University researcher, said the study involved 138 expectant couples discuss things bothering them. He measured the stress hormone cortisol before, right after and 20 minutes after the discussion.
The team found that men's increased stress levels -- measured by the amount of the stress hormone cortisol -- during a conflict discussion depended on the level of hostility the couple expressed. More hostility led to a larger stress reaction for men, but the stress levels of the pregnant women during the discussion were not linked to the amount of hostility expressed.
The team also found that recovery from the conflict discussion -- measured by assessing cortisol levels 20 minutes later -- did not differ for men and women with low levels of anxiety.
However, men with a high level of anxiety recovered less, whereas women with high anxiety recovered more if the couple had expressed a high level of hostility during the discussion.
"Hostility and negativity in a relationship has been shown to have a major impact on mental health and the future well being of the couple," Feinberg said in a statement
"It is especially important to understand how relationship conflict may affect stress during pregnancy, as maternal stress has been linked to health problems for both the mother and child. And men who have difficulty dealing with stress could end up reacting angrily to future disagreements, which could affect the quality of the relationship, parent-child relations and children's adjustment."
The study was published in the Journal of Psychology.