These tables present a summary of the maternal and newborn information for all women with a known birth in 2011. Data presented is sourced from the National Maternity Collection (MAT). MAT integrates maternity-related data from the National Minimum Dataset and Lead Maternity Carer (LMC) claim forms.
Key findings for 2011:
- Overview
- Maternal demographic profile
- Labour and birth
- Plurality
- Home births
- Babies
- Women registered with a Lead Maternity Carer
- Maternity facilities
Overview
In 2011, 62,362 women giving birth and 62,733 liveborn babies were recorded in the National Maternity Collection. The national birth rate was 6.8 completed pregnancies per 100 women of reproductive age.
Maternal demographic profile
The majority of women (53.0%) giving birth were aged 25–34 years. Similarly, rates of birth were highest for the 30–34 years (12.3 per 100 women of reproductive age) and 25–29 years (10.6 per 100 women of reproductive age) age groups.
Women giving birth were distributed by ethnic group as follows: European (49.5%), Māori (25.5%), Pacific Peoples (11.5%), Asian (11.5%), and Other (2.0%). Rates of birth were highest for the Pacific Peoples and Māori (10.7 and 10.5 per 100 women of reproductive age, respectively).
Over a quarter (27.8%) of all women giving birth resided in the most socioeconomically deprived areas (deprivation quintile 5). A higher proportion of Pacific and Māori women lived in these areas compared to European women (59.8% and 45.0% of Pacific and Māori women compared to 13.3% of European women).
Rates of birth by district health board (DHB) ranged between 5.5 and 8.5 per 100 women of reproductive age, with the highest rates for Northland (8.5 per 100 women of reproductive age) and Tairawhiti (8.4 per 100 women of reproductive age) DHBs.
Labour and birth
Two-thirds (66.6%) of women gave birth by spontaneous vaginal delivery (including home births), with the percentage of spontaneous vaginal births decreasing with maternal age (77.8% of women under 20 years of age compared to 53.9% of women aged 40 years and over).
Over 70% of Māori and Pacific women gave birth by spontaneous vaginal delivery (76.9% and 74.6%, respectively).
Almost a quarter (24.3%) of women giving birth had a caesarean section. The percentage of women giving birth by caesarean section increased with maternal age (13.0% of women under 20 years of age compared to 39.2% of women aged 40 years and over), but decreased with levels of socioeconomic deprivation of residence (30.1% of women residing in the least deprived areas compared to 19.6% of women residing in the most deprived areas).
Just over half (54.3%) of women giving birth by caesarean section had an emergency caesarean section. The proportion of caesarean sections that were emergency caesarean sections was highest for younger women giving birth (82.9% of women under 20 years of age and 68.7% of women aged 20−24 years), Pacific women (63.8%), and for women living in the most socioeconomically deprived areas (62.0% for deprivation quintile 5).
Among women giving birth (excluding elective caesarean sections), 21.6% had an induction, 24.7% were administered with an epidural and 27.1% required an augmentation of labour. The percentage of women requiring an induction increased with maternal age (17.4% of women under 20 years of age compared to 37.8% of women aged 40 years and over); the opposite trend was seen with the percentage of women requiring an augmentation of labour (33.4% of women under 20 years of age compared to 15.8% of women aged 40 years and over).
Approximately 12% of women giving birth vaginally had an episiotomy in 2011. The population most likely to have an episiotomy was women of Asian ethnicity (24.2%).
Plurality
A total of 901 women giving birth (1.5%) had twins or multiple births. The majority of women with singleton pregnancies had a spontaneous vaginal birth (67.3%) while the majority of women with twin or other multiple pregnancies had a caesarean section (61.9%).
Home births
In 2011, 3.6% of women giving birth intended to birth at home and 3.3% of women actually gave birth at home.
The percentage of actual home birth was highest among older women (3.8% of women in the 35–39 years and 40 years and over age groups), Māori and European women (4.0% of women in both ethnic groups), and women residing in West Coast DHB (12.7%).
Babies
There were slightly more male babies born (51.3%) than female babies (48.7%). Almost half (48.1%) of babies born were European and a further 26.8% were Māori. There were more babies born residing in the most socioeconomically deprived areas (28.0% residing in deprivation quintile 5) than those born residing in the least socioeconomically deprived areas (14.1% residing in deprivation quintile 1).
The average birthweight for male babies born was 3.47kg, with female babies weighing less on average at 3.37kg.
In 2011, 7.4% of all liveborn babies were born preterm (<37 weeks gestation). Māori babies (8.2%) and babies born to mothers aged 40 years and over (9.6%) were most likely to be born preterm.
Babies of Asian ethnicity were most likely to be born full-term (≥37 weeks gestation) with a low birthweight (<2.5kg) (2.6% of Asian babies compared to 1.6% of all liveborn babies).
Women registered with a Lead Maternity Carer
In 2011, 87.3% of women giving birth registered with a Lead Maternity Carer (LMC) to receive primary maternity care during the pregnancy and postnatal period and 12.7% either received primary maternity care through DHB services or received no care.
The least likely groups to register with a LMC were women residing in West Coast or Counties Manukau DHBs (34.3% and 66.8%, respectively), Pacific women (65.5%) and women residing in the most socioeconomically deprived areas (78.1% for deprivation quintile 5).
Among women registered with a LMC
- almost 95% registered with a LMC within the first two trimesters of pregnancy (61.8% registered in the first trimester)
- over 90% registered with a midwife LMC
- 40.7% reported no previous births (nulliparous) and 33.4% reported one previous birth
- 15.3% were identified as smokers at time of LMC registration, with higher percentages of smokers among younger women (34.2% of women under 20 years of age), Māori women (37.0%), and women residing in the most socioeconomically deprived areas (26.2% for deprivation quintile 5).
Over three-quarters (76.3%) of babies born to women registered with a LMC were breastfed either exclusively or fully.
Maternity facilities
Over 85% of women gave birth at a secondary (40.9%) or tertiary (45.7%) facility in 2011, with a further 10.1% giving birth at a primary facility and 3.3% giving birth at home.
The use of primary and secondary facilities decreased with maternal age (13.4% and 48.2%, respectively, for women under 20 years of age, compared to 6.5% and 37.9%, respectively, for women aged 40 years and over age group) whilst the use of tertiary facilities increased with age (38.4% of women in the under 20 years age group compared to 55.6% of women in the 40 years and over age group).
The proportion of women giving birth at a secondary or tertiary facility ranged between 90% and 95% for all ethnic groups except the Māori ethnic group (83.3%).
The use of secondary or tertiary facilities was fairly even across all levels of socioeconomic deprivation, ranging between 89.4% and 91.4% for each deprivation quintile in 2011.
Note: the denominator for percentage calculations is the total for each variable where information was recorded (i.e. excludes ‘Not stated’).