Findings that suicide is the leading cause of death for expecting or new mums have prompted calls for a specialist unit in the North Island.

The annual report of the Perinatal and Maternal Mortality Review Committee has found suicide to be the leading cause of death among pregnant women in New Zealand and women with newborn babies of up to six weeks.

The report also found that one in five perinatal deaths - death of an unborn or newborn baby - could have been prevented.

The findings have led to recommendations aimed at reducing maternal suicides, including the establishment of a mother and baby unit in the North Island in addition to the unit based in Christchurch, PMMRC Chair Professor Cynthia Farquhar said.

"Another recommendation is the referral of pregnant women and new mothers with a history of mental illness for psychiatric assessment and management even if they are currently well.

"There also needs to be better co-ordination between existing services in the primary and specialist sectors and processes for sharing information between providers."

A quarter of all maternal deaths in New Zealand in the years 2006 to 2010 were suicide (13 cases). Other common causes were maternal pre-existing medical conditions (11 cases) and amniotic fluid embolism (nine cases).

New Zealand's maternal mortality rate is significantly higher than that in the United Kingdom.

In terms of perinatal deaths, the report found there were 704 in 2010. These included 211 due to a congenital abnormality, 111 due to pre-term birth, and 78 due to haemorrhage during pregnancy.

Professor Farquhar says the report found that 124 (one in five) perinatal deaths and 18 (one in three) maternal deaths were potentially avoidable.

"Every one of these deaths is a tragedy. While some were not preventable, we can learn from others to help reduce deaths in the future."

The most common factors contributing to the potentially avoidable deaths of babies and mothers were a lack of access to health services. This included not booking for pregnancy care, issues with the skills of health care professionals, and organisational factors such as a lack of protocols or delays in procedures.

- © Fairfax NZ News