International comparisons of maternal mortality are based on statistics produced by the World Health Organisation (WHO). In calculating the maternal mortality ratio (MMR), the WHO takes account of vital statistics as compiled by national statistical offices (i.e. the Central Statistics Office in the case of Ireland) but also applies a separate weighting to adjust for potential under-reporting. For most developed countries, including Ireland, the weighting factor is 1.5. The most recently published WHO statistics are based on this methodology.
As the Deputy is aware, Ireland recently implemented a Confidential Maternal Death Enquiry (MDE) system using the same model which has been in operation in the United Kingdom (UK) for many years. The first report of the MDE for Ireland was published in 2012 and covered the years 2009 to 2011. Future WHO analysis for Ireland will take account of the MDE results.
Comparison with the UK's most recent MDE shows Ireland with a ratio of 8.6 maternal deaths per 100,000 maternities (2009 to 2011) compared with 11.4 maternal deaths per 100,000 maternities (2006 to 2008) for the UK. It needs to be emphasised that Ireland and the UK are virtually unique in having fully comprehensive MDE reporting systems. The WHO recognises that international rankings of maternal mortality are, therefore, problematic given the difficulty of obtaining accurate estimates of the levels of under-reporting which exist in most countries.
Nevertheless, taking full account of the MDE results, Ireland has amongst the lowest levels of maternal mortality in the developed world and this will continue to be reflected in WHO statistics. Finally, it also needs to be noted that Ireland is a small country and rare occurrences such as maternal mortality will be subject to significant fluctuations in rates where the data are based on a single year or even where data are aggregated over several years. As evidence of this, the 95% confidence limits for the maternal mortality ratio (MMR) in Ireland's MDE covering a three year period (2009 to 2011) range from 4.6 to 12.4 maternal deaths per 100,000 maternities.
