Getting to grips with maternal death rates

Ireland, we have been told over recent weeks, is one of the the safest countries in the world to be pregnant and have a baby. According to figures from the Central Statistics Office (CSO) for 2009, there were four maternal deaths per 100,000 live and still births.

However, experts here now say that figure is an underestimate and the rate is double that.

The World Health Organisation (WHO)defines a maternal death as: “The death of a woman while pregnant or within 42 days of termination of pregnancy, irrespective of the duration and site of the pregnancy, from any cause related to or aggravated by the pregnancy or its management but not from accidental or incidental causes.”

According to figures in the Confidential Maternal Death Enquiry (MDE) in Ireland, Report for the Triennium 2009–2011, the maternal death rate here is eight per 100,000. Dr Michael O’Hare, consultant obstetrician at Daisy Hill hospital in Newry, Co Tyrone and chairman of the Maternal Death Enquiry group, says the higher rate comes from far more thorough data gathering than that gleaned solely from the civil register of deaths.

The MDE, a joint collaboration of the Institute of Obstetricians and Gynaecologists and the HSE, was established in 2007 to gather more accurate data on maternal deaths, for reasons of accuracy as well as to learn how better to save mothers’ lives.

“We are confident that the figures we have covering 2009 to 2011 are certainly the most accurate available and that the rate up to now has been hugely underestimated,” says Dr O’Hare.

Dr O’Hare explains that up to 2009, data was based only on figures as recorded by the CSO. Though the CSO has a robust system for collating data, there are internationally recognised problems with relying on civil registration to record maternal death rates.

Death certificates

Not all maternal deaths are recorded as such on death certificates, he says, partly due to inconsistent notification from coroners. There are also instances where maternal deaths in the community are not recorded as maternity-related.

According to a 2005 report on maternal mortality by the WHO, Unicef, UNFPA (United Nations Population Fund) and the World Bank, in 2005 Ireland had one reported maternal death per 100,000.

As that report says: “Even in developed countries where routine registration of deaths is in place, maternal deaths may be underreported and identification of the true number of maternal deaths may require additional special investigations into the cause of deaths.

“A specific example of such an investigation is the Confidential Enquiry into Maternal Deaths [CEMD] which was established in the United Kingdom in 1928.”

The same report continues: “The most recent report of the CEMD (2000-2002) identified 44 per cent more maternal deaths than was reported in the routine civil registration system.”

And it is this more thorough, empirically robust system, as pioneered by the British CEMD, that is now being implemented here. Not only does it use a far wider network of reporting systems than heretofore, but as in Britain, the death of a mother up to one year after end of pregnancy – not just six weeks – is now recorded as a maternal death.

This allows for a far more accurate record of pregnancy-related suicide than had been possible with a 42-day window.

The project has been co-ordinated from Cork University Maternity Hospital by Edel Manning.

According to Dr Michael O’Hare: “[Edel Manning] has established contacts with all coroners, maternity units, general hospitals, public health nurses and GPs the length and breadth of the 26 counties. The same gold standard as in the UK has been adopted.

“As a result of Edel’s work, issues have been identified that may have prevented maternal deaths being accurately recorded. The many links she has established within obstetrics and maternity services means there is a high level of awareness and support for the MDE.”

While direct maternal deaths tended to occur in hospitals and maternity units, the indirect deaths, particularly suicide, occur in the community, he says.

“Particularly those deaths associated with post natal depression, these are the ones that have been poorly recorded. So, to be as complete as we can, we have been asking community health professionals, like the public health nurses, to return deaths occurring up to one year after pregnancy’s end. Suicides often occur after 42 days after the end of pregnancy.”

There were 25 maternal deaths between 2009 and 2011. Six were direct maternal deaths – pulmonary embolism (three); amniotic fluid embolism (one); uterine rupture (one), and multi-organ failure secondary to HELLP syndrome. Some 13 were indirect deaths – cardiovascular disease (five); suicide (two); HINI Influenza (two); epilepsy (two); chronic obstructive pulmonary disease (one), and bleeding oesophageal varices (one).

Other deaths amounted to six – metastatic, or spreading, cancer (two); road traffic accident (one); CNS Lymphona (one) and substance abuse (two).

At the time of writing the report, there were no data on the number of maternities for 2011. However, for the years 2009 and 2010 there were 149,128 maternities and 12 maternal deaths, giving a maternal death rate of eight per 100,000.

The Irish figures compare favourably with Britain, which had a death rate of 11 per 100,000 births between 2006 and 2008, though not as well as with Norway which had seven maternal deaths per 100,000 births, or Sweden which had five per 100,000, both in 2008.

Validity questions

These figures point perhaps to questions about the validity, on either side of the abortion debate, of using maternal death rates as arguments for liberal or a restrictive abortion provision.

“I have serious doubts about the validity of the arguments,” says Dr O’Hare. “If you look at Britain which it is acknowledged has fairly liberal abortion legislation, they are not doing any better than us, while the Scandinavian countries which are doing better also have liberal provision.”