Research on the wellbeing of fathers has prompted a call for expectant dads to be screened for symptoms of depression.
More than 3500 New Zealanders took part in the study published today in the Journal of the American Medical Association.
It found one in 50 prospective fathers were depressed in the lead-up to childbirth, and one in 25, felt down afterwards.
Poor health and stress were said to be aggravating factors for the 217 men who became depressed.
Research fellow and the study's author Lisa Underwood of Auckland University said there should be a focus on both the mother and father's mental health.
She said when men went to see medical specialists during the pregnancy, it could be an opportunity to include them in discussing mental health.
"When you think that there are 60,000 New Zealand births each year, we're talking about nearly 1400 children affected, potentially, by anti-natal paternal depression and more than 2500 New Zealand children affected by paternal post-natal depression, each year."