Fetal and Infant Deaths 2008 and 2009

Summary

The purpose of the Fetal and Infant Deaths publication series is to inform discussion and assist future policy development. Readership of this publication is wide-ranging, and its contents reflect this, aiming to meet the needs of all interested parties.

The Fetal and Infant Deaths series presents data on deaths that occurred before one completed year of life. This particular publication focuses on deaths that were registered in the 2008 and 2009 calendar years.

Key findings:

Overview

• In 2009 there were 482 fetal deaths registered compared to 555 in 2008. This equates to rates of 7.6 deaths per 1000 total births in 2009 and 8.4 in 2008.
• The fetal death rate remained relatively stable between 1996 and 2009.
• There were 324 infant deaths in 2008 compared to 332 in 2009.  This equates to rates of 5.0 and 5.2 deaths per 1000 live births.
• There has been a 27.7% decrease in the infant death rate since 1996.

Cause

• The most common specified cause of fetal death was Slow fetal growth and fetal malnutrition (9.5%).
• Fetal death of unspecified cause accounted for 34.9% of all fetal deaths.
• The most common cause of infant death was Disorders related to short gestation and low birthweight (14.3%).

Gestation

• The majority (62.8%) of fetal deaths in 2008 and 2009 occurred before 32 weeks gestation.
• Of infants who died in 2008 and 2009, 42.4% were born very pre-term (before 32 weeks gestation), 13.0% were pre-term and 37.2% were born at term.

Birthweight

Over half of all fetal deaths had an extremely low birthweight (less than 1000g).

In 2008 and 2009, over a third (34.8%) of all infant deaths were infants with an extremely low birthweight (less than 1000g).

Ethnicity

• Pacific had the highest fetal death rates in 2009 at 9.3 deaths per 1000 births.
• The fetal death rate for Maori was 8.1 deaths per 1000 births compared to 7.0 for the Other  ethnic group.
• The Maori infant death rate was nearly twice the Other rate in both 2008 and 2009.
• The Maori rate has decreased 35.5% between 1996 and 2009. The Pacific rate decreased 15.7%.

Deprivation

• In 2009 there were 8.2 fetal deaths per 1000 births in areas of high deprivation (quintiles 4 and 5) compared to 6.4 deaths in the least deprived areas (quintile 1).
• There has been a significant decrease in the infant death rates for quintiles 2 and 4 since 1996 (48.5% and 39.8%).

Maternal age

• Mothers under 20 years of age had the highest rate of fetal death (10.7 deaths per 1000 births in 2009).  Mothers over 35 years had the second highest rate.
• The infant death rate for mothers under 20 years of age was significantly higher than the rate for mothers over the age of 25 years.

District Health Board

• Waitemata and Counties Manukau DHBs had fetal death rates significantly higher than the national rate.
• Counties Manukau and Waikato DHBs had infant death rates significantly higher than the national rate (6.9 and 6.2 deaths per 1000 live births compared to 5.0)

Age

• The majority of infant deaths occur before one month of age with 31.3% occurring within 24 hours of birth,  14.2% between one and six days of age, and 13.3% between seven and 27 days of age.
• The death rate for infants aged one to 11 months (post-neonatal) declined 36.8% between 1996 and 2009.

Sex

• In 2009 the male infant death rate was 5.6 deaths per 1000 live births compared to a rate of 4.9 for female infants.
• Males have had a higher infant death rate than females since 1996.

Sudden Infant Death Syndrome (SIDS)

• SIDS rates were highest for younger mothers, Maori and mothers from the most deprived areas.
• SIDS deaths are most likely to occur between one and four months of age (64.5%).