New research suggests that men's mental health risk increases sharply around the arrival of a new baby.

Researchers at Australian National University found that anxiety around the arrival of a new baby is just as common as postnatal depression, and the risks for men are nearly as high as for women.

"Men can feel left out of the process, because pregnancy and childbirth are so integrally linked to the mother," mental health researcher Dr. Liana Leach said in a statement. "It can compound the problem. They don't seek help, because they think 'it's not so much about me'."

Researchers reviewed 43 separate studies and found anxiety before and after a child arrives is just as prevalent as depression, affecting around one in ten men, around half the rate for women.

The causes of anxiety and depression around the arrival of a new baby are poorly understood. While results from individual studies vary, some studies suggest over 20 percent of parents suffer from anxiety or depression.

"Having a new baby is a time of great adjustment for many parents, and it is normal to be nervous, but anxiety can become a problem when it persists for extended periods and interferes with every day functioning," Leach said.

Symptoms of anxiety can include worrying or feeling keyed up much of the time, feeling irritable, and fears for the baby's safety. Physical symptoms can include a racing heart, feeling sweaty, poor sleep and poor appetite.

"Couples should be aware of their mental health right from when they realise they are pregnant. Early intervention reduces the severity and duration of symptoms."

Risk factors include lack of social support, especially from a partner, financial difficulties and a history of mental health problems.

"Health care during the perinatal period should be about the whole family," Leach said.

The study has been accepted for publication in the Journal of Affective Disorders.