Fetal and Infant Deaths 2011

Summary

These tables present a summary of fetal and infant deaths, with a focus on deaths and stillbirths registered in 2011 with the Births, Deaths, Marriages and Citizenship Registry (BDM). Information presented includes demographic information (eg, ethnicity and sex), cause of death, gestation and birthweight, as well as deaths classified as sudden infant death syndrome (SIDS) and sudden unexpected death in infancy (SUDI).

This dataset is a continuation of the Fetal and Infant Death series.

Key findings for 2011

Overview

• There were 450 fetal deaths and 323 infant deaths registered with Births, Deaths, Marriages and Citizenship in 2011.
• This equates to a fetal death rate of 7.2 per 1000 total births and an infant death rate of 5.2 per 1000 live births.
• Between 1996 and 2011 there was a significant decrease in the infant death rate (from 7.3 to 5.2 per 1000 live births) while the fetal death rate fluctuated between 5.9 and 8.6 per 1000 total births.

Ethnic group

• The fetal death rate was similar for Māori, Pacific peoples and Other ethnic groups in 2011 (7.3, 7.1 and 7.1 per 1000 total births, respectively).
• Infant death rates for Māori (7.7 per 1000 live births) and Pacific peoples (6.4 per 1000 live births) were 2.1 and 1.7 times, respectively, the rate for the Other ethnic group (3.7 per 1000 live births).

Maternal age group

• In 2011, the fetal death rate was highest among mothers aged 35­–39 years (9.0 per 1000 total births) and lowest among mothers aged 30–34 years (6.3 per 1000 total births).
• Mothers aged under 20 years and 20–24 years had the highest rates of infant death (10.3 and 7.0 per 1000 live births, respectively).
• The infant death rate was 4.2 per 1000 live births for mothers aged 25 years and over.

Socioeconomic deprivation of residence

• Infant death rates increased with increasing levels of socioeconomic deprivation of residence. The infant death rate for deprivation quintile 5 (most deprived) was 8.5 per 1000 live births − five-times the rate for deprivation quintile 1 (least deprived) (1.7 per 1000 live births).
• Fetal death rates ranged between 6.8 and 7.7 per 1000 total births for each deprivation quintile of residence.

Gestation

• Almost 80% of fetal deaths were preterm (<37 weeks gestation), the majority of which were very preterm (<32 weeks gestation). A further 19.8% were at term (37–41 weeks gestation).
• Of the infant deaths registered in 2011, 58.8% were born preterm (<37 weeks gestation), the majority of which were born very preterm, and 36.2% were born at term (37–41 weeks gestation).

Birthweight

• Approximately 59% of fetal deaths and 38% of infant deaths registered in 2011 had an extremely low birthweight (<1000g).

Cause of death

• Over 70% of fetal deaths had a cause of death in the ICD-10 chapter group ‘Certain conditions originating in the perinatal period (P00–P96)'; the most common specified cause of fetal death being ‘Slow fetal growth and fetal malnutrition (P05)’, followed by ‘Disorders related to short gestation and low birth weight, not elsewhere classified (P07)’.
• ‘Fetal death of unspecified cause (P95)’ accounted for 38.9% of all fetal deaths.
• The most common cause of infant death was ‘Disorders related to short gestation and low birthweight (P07)’ (14.9%).
• ICD-10 chapter groups ‘Certain conditions originating in the perinatal period (P00–P96)’ and ‘Congenital malformations, deformations and chromosomal abnormalities (Q00–Q99) accounted for 45.5% and 23.8%, respectively, of fetal deaths.

Sudden unexpected death in infancy (SUDI) and sudden infant death syndrome (SIDS)

• There were 54 deaths recorded as sudden unexpected death in infancy (SUDI) in 2011, including 24 sudden infant death syndrome (SIDS) deaths.
• These SUDI deaths included 35 males and 19 females.
• Over the five-year period 2007–2011, the highest rates of SUDI were among infants with a very low birthweight (1000g–1499g) (4.3 per 1000 live births), young mothers aged under 20 years (2.9 per 1000 live births), and infants who were very preterm (<32 weeks gestation ) (2.7 per 1000 live births).

District health board region

• There was a wide range of fetal and infant death rates across district health boards (DHBs).
• The rate of fetal death was highest for Hutt Valley DHB (10.1 per 1000 total births) and lowest for South Canterbury DHB (1.7 per 1000 total births).
• The rate of infant death was highest for Tairawhiti DHB (10.6 per 1000 live births) and the lowest was for Wairarapa DHB (1.9 per 1000 live births).

Note: the number of fetal and and infant deaths in New Zealand is small and may cause rates to fluctuate markedly from year to year. Rates derived from small numbers should be interpreted with caution.