Māori and non-Māori differences in caesarean section rates: a national review

To investigate the relationship between caesarean section (CS), deprivation, and ethnicity; and to examine Māori/non-Māori differences in CS after controlling for possible confounding factors.

Total, acute, and elective CS rates (as proportions of women giving birth in New Zealand hospitals) during 1997-2001 were examined by ethnicity and area deprivation. Logistic regression was used to adjust for age, deprivation, some clinical factors, and District Health Board (DHB).

Total, acute, and elective CS rates were significantly higher among non-Māori compared to Māori women (total CS, 21% vs 13%, ratio 1.59, p<0.0001). CS rates decreased with increasing levels of deprivation. After controlling for deprivation and age, differences between Māori (M) and non-Māori (nM) remained (total CS odds ratio nM:M 1.43, 95% confidence interval 1.39-1.48; elective OR 1.44 (1.36-1.52); acute OR 1.38 (1.33-1.43)). Differences also remained after controlling for other factors including a limited number of clinical factors.

Results suggest that non-clinical factors may be contributing to ethnic differences in CS in New Zealand. While deprivation contributes to this difference it does not fully explain it. Further research is needed to investigate whether ethnic differences in CS impact on birth outcomes, and which factors, other than those clinically indicated, contribute to ethnic differences in caesarean section in New Zealand.