Its a huge life change and theirs no doubt that a baby everything, while it may be a great thing, theirs no doubting that its traumatic. Those with pre-existing mental health problems are no doubt more at risk of developing depression but theirs no telling who will be effected.
Depression can begin during pregnancy as relationships start changing, the house begins to change and suddenly their is increased attention upon you both from friends and relatives.
Their also seems to be a tendency that women can feel they do things best,such as changing a nappy or rearranging the house, and may be quick to criticise their partners and take over. This can lead to the man loosing his confidence. And as can frequently be seen from counseling sessions, the partner may stop offering to help which potentially leads to resentment."
The main concern is that Men are expected to just cope with it. Theirs the worry that you cannot burden the mother anymore with your concerns and also that admitting to depressive feelings also is a failing in what should be an exciting extension of your life. So as with many issues in life, men tend to avoid seeking help and turn to drink, self-medication and having affairs as a coping mechanism.
Remember depression brought on by anxiety about their new circumstances.
Support each other and look out for tell-tale signs in your partners.