A study came out yesterday confirming that women who have multiples are at a higher risk for postpartum depression. This new study, conducted at Johns Hopkins and appearing in the journal Pediatrics, found that these mothers are actually have a 43% higher risk. What we still don't know for sure is why. As reported on MedPage Today:

"[The researchers] said their work was limited in identifying mechanisms for the increased risk of depressive symptoms among mothers of multiple births because of a lack of data on psychosocial covariates of maternal depression such as spousal support and marital relationship.

The researchers said, too, that little documentation is available regarding hormonal changes and dysregulation in women associated with multiple births. They were also not able to factor infertility treatments into the analysis.

Although we do know that infertility puts moms in a higher risk category for PPD as well.