Suicide is the leading cause of death for pregnant women and new mothers, and a new study has found more than 30 per cent of maternal deaths are avoidable.
The annual report of the Perinatal and Maternal Mortality Review Committee has recommended women with a history of mental illness should be referred for psychiatric assessment when they fall pregnant, even if they are well.
The report, released this afternoon, says New Zealand's maternal mortality rate - the death of a mother while pregnant or up to six weeks after birth - is "significantly higher'' than in the United Kingdom.
The perinatal mortality rate - the death of a baby from 20 weeks gestation to 28 days after birth - is comparable with the UK but higher than in Australia.
Committee chairwoman Professor Cynthia Farquhar said the report found one in five of the 704 perinatal-related deaths in 2010 were avoidable.
In the study period, from 2006 to 2010, 13 of the 57 maternal deaths were from suicide.
Ms Farquhar said as well as implementing tighter policies for treating pregnant women with a history of mental illness, a specialist mother and baby unit was needed in the North Island to supplement New Zealand's sole unit, in Christchurch.
"There also needs to be better coordination between existing services in the primary and specialist sectors and processes for sharing information between providers,'' she said.
Other most frequent causes of maternal death in the study period were pre-existing medical conditions (11 cases) and amniotic fluid embolism (nine cases).
The leading cause of perinatal deaths in 2010 were congenital abnormality (211 cases), pre-term birth (111 cases) and haemorrhage during pregnancy (78 cases).
"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,'' Ms Farquhar said.
"The report aims to identify where maternity and neonatal services should focus to make the greatest difference.
"New Zealand has very good maternity services but there is always scope to learn and improve.''
She said the most common factors contributing to the avoidable deaths of babies and mothers were not being able to access the necessary health services, such as not booking for pregnancy care, issues with the skills of healthcare professionals and organisational factors like a lack of protocols or delays in procedure.
"Maternity providers need to consider the recommendations from this report and seek to implement them,'' Ms Farquhar said.
Maori and Pacific mothers are more likely to have stillbirths and neonatal deaths compared to New Zealand European and non-Indian Asian mothers.
Teenage mothers are at a higher risk of perinatal-related mortality compared to mothers aged between 20 and 39. Mothers of 40 years and older are also at an increased risk.
Nine per cent of mothers reported using alcohol and 3.4 per cent using marijuana during pregnancy.
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