Does the percentage of mothers who were getting fertility treatment make this actually representative? The pain and suffering that those who struggle to have children followed (presumably!) by happiness when they have a child must have some effect?
The average age of the participants also seems high to me, but a brief search for an average age for having a first child put this study cohort only slightly over that - surprising to me at least.
Baby blues and postnatal depression are common, even among people who've been through fertility treatment. Indeed, those people may find it harder to seek help because of the assumptions that they must be happy after all that struggle.
(Also, about 1 in 10 men have postnatal depression.)
This is true, but two years down the track one would hope this had passed. I know that long term health problems do occur but I don't think anyone would describe them as post-natal depression or baby blues at that point.
The average age of the participants also seems high to me, but a brief search for an average age for having a first child put this study cohort only slightly over that - surprising to me at least.