The study looked at a specific group of moms - highly educated, mostly married Midwestern women who had full-time jobs - and found that those who felt societal pressure to be perfect moms and who identified most strongly with their motherhood role posted more frequently than others to Facebook.
These same mothers who posted most frequently also reported stronger emotional reactions to comments on the photos they posted of their new baby, such as feeling bad if they didn't get enough positive comments.
While many new mothers are active on Facebook, these results suggest some seem to be more drawn to the site than others and may use it in less-than-healthy ways, said Sarah Schoppe-Sullivan, lead author of the study.
"If a mother is posting on Facebook to get affirmation that she's doing a good job and doesn't get all the 'likes' and positive comments she expects, that could be a problem. She may end up feeling worse," Schoppe-Sullivan said.
In fact, those mothers who posted more on Facebook tended to report more depressive symptoms after nine months of parenthood than other moms.
127 mothers from Ohio participated in this study.
The researchers also measured the frequency of their Facebook activity since their child was born, how often they uploaded photos of their children to Facebook and their emotional responses to Facebook friends' comments and likes of child photos.
Moms also reported how often they felt depressive symptoms at three and nine months after giving birth.
The study showed that the new moms in the study nearly universally used Facebook to share about their child - 98 percent said they had uploaded photos of their infant.
The average new mom reported a slight increase in Facebook use since her baby was born.
This study has been published in Sex Roles.