It's not only women who suffer from postnatal depression - men can get it too.
While for many fathers the arrival of a baby is a magical, life changing moment, new research reveals as many as one in 25 New Zealand men experienced post-natal depression.
The Growing Up in New Zealand study investigated depression symptoms in more than 3500 men during the third trimester of their partner's pregnancy, and again nine months after their child was born.
It found that 2.3 percent of fathers (one in 43) experienced depression during the pregnancy, increasing to 4.3 percent (one in 23) nine months after their child was born.
By comparison, earlier figures found one in eight mothers experienced depression symptoms during pregnancy, with one in 12 experiencing symptoms post-natally.
Study author Dr Lisa Underwood, from the University of Auckland, says that while pre- and post-natal depression has been studied extensively in mothers, there has been little done to identify symptoms in men.
"As in many other countries, New Zealand women are assessed for postnatal depression following childbirth," says Dr Underwood.
"There is no routine screening of women during pregnancy and none for fathers before or after the birth of their children, since they are not usually engaged in routine perinatal care."
Stress, poor health and relationship problems put men at higher risk.
"Increasingly, we are becoming aware of the influence that fathers have on their children's psychosocial and cognitive development," Dr Underwood says.
"Given the potential for paternal depression to have direct and indirect effects on children, it is important that we recognise and treat symptoms among fathers early."
She says the first step in doing this is to raise awareness.