2005 - National Women's Hospital - Auckland District Health Board

clinical record and data in Healthware amended where appropriate. Further checking
was undertaken against gestation recorded in the perinatal mortality database for
perinatal deaths and the neonatal database for all neonatal unit admissions. The clinical
record was checked where gestation varied by at least 1 week in these instances.
Because of the incomplete reconciliation of data sets, there may be a minimal number of
cases where gestation varies in reporting of the neonatal and maternity data.
Ethnicity
Ethnicity is collected at registration at the hospital with the standard census 2001
question. Three options are input into the CMS (Case Management System) database.
In preparing the data for this report, each mother has been allocated to a single ethnic
group. When more than one ethnic group is recorded, the prioritised ethnicity system
outlined in ‘Ministry of Health. 2004. Ethnicity Data Protocols for the Health and Disability
Sector. Wellington: Ministry of Health.’ (available online at
http://www.nzhis.govt.nz/documentation/ethnicity/index.html) has been used.
The most summarised (Level 1) prioritisation is as follows: Maori, Pacific peoples, Asian,
other groups except NZ European, NZ European. To this, we have added ‘Other
European’ and split ‘Indian’ from Asian, either because these are a large group in our
population and/or because their obstetric risk profile is significantly different from the
remaining women in the ‘Other’ or ‘Asian’ category. In the majority of figures in this
document, these categories are recombined, and the small category of women with
‘Unstated’ ethnicity has been excluded. Level 2 prioritisation is given in Appendix 1.
Standard primipara
A woman with
• no prior birth > 20 weeks,
• aged 20-34 years at index birth,
• with a singleton pregnancy,
• cephalic presentation,
• gestation 37-41 weeks,
• baby not small for gestational age (customised centile >10 th ),
• no medical disease (defined as no history of cardiac disease, renal disease,
mental health disorder, SLE, HIV infection, or CVA/TIA) diabetes or hypertension,
• no gestational diabetes in index pregnancy,
• no pregnancy associated hypertensive disease in index pregnancy,
• and no antepartum haemorrhage during index pregnancy.
Onset of birth
This variable has been redefined from the 2004 report to include a 4 th pathway
‘emergency Caesarean before the onset of labour’ which was previously included with
spontaneous onset of birth. There are 4 pathways to birth included in this report: (1)
elective caesarean section, (2) emergency caesarean before the onset of labour, (3)
induction of labour, and (4) spontaneous onset of labour.
Mode of birth for multiple pregnancies
For analyses where the denominator is mothers, mode of birth is represented as the
mode of birth of the baby requiring most intervention. Mode of birth has been prioritised
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