Maternal mortality, despite its rarity in wealthy countries, is a fundamental indicator not only of health but also of the quality of the healthcare system in general, and perinatal care in particular. It is considered to be a ‘sentinel event’, the occurrence of which is indicative of dysfunctions, often cumulative, in the healthcare system. In addition to the classic epidemiological surveillance findings – number of deaths, maternal mortality ratio, distribution of medical causes, sub-groups of women at risk – its study makes it possible, through a precise analysis of the history of each woman who dies, to highlight areas for improvement in the content or organisation of care, the correction of which will make it possible to prevent deaths as well as upstream morbid events involving the same mechanisms. The maternal mortality profile therefore provides information not only on the risk attributable to pregnancy and childbirth, but also on the performance of the healthcare system.
To achieve this epidemiological and clinical audit objective, an enhanced ad hoc system is necessary and recommended by international bodies, because routine vital mortality statistics, derived from analysis of the contents of death certificates, do not allow a satisfactory assessment of maternal mortality – significant under-estimation, biased profile of causes, lack of information on the care pathway -.

In recognition of this need, the Enquête Nationale Confidentielle sur les Morts Maternelles en France (National Confidential Enquiry into Maternal Deaths in France) was set up, at the instigation of INSERM epidmiologists and professional societies of obstetrics clinicians (national college of ObGyn –CNGOF- and national society of anesthesia and intensive care –SFAR-), with strong initial support from the public authorities. The decree issued by the Ministry of Health (founding decree, J.O. 2 May 1995) gave it the task of examining maternal deaths, identifying the factors involved in these deaths and proposing preventive measures.

Since 1996, the Enquête Nationale Confidentielle sur les Morts Maternelles (ENCMM) has been carried out continuously in France. Scientific responsibility for and coordination of this ongoing system was initially entrusted to INSERM unit 149, which became Unit 953, then U1153 team EPOPé (Obstetrical Perinatal and Paediatric Epidemiology) since 2014.
The ENCMM system was initially inspired by the pioneering example of the United Kingdom, where a confidential survey of maternal deaths has existed for seventy years. However, the current organisation is the result of changes to the system, adapted to the French national context.

The ENCMM studies all maternal deaths in France, with a twofold objective:

1. epidemiological characterisation of maternal mortality and its evolution – level, risk factors, cause profile – using a quantitative approach.
2. analysis of the circumstances in which the morbid event occurred and of the management of the fatal outcome, in order to identify areas for improvement, using a mainly qualitative approach.

This national system has a dual role of surveillance and research.

• It produces maternal mortality indicators (level, causes and sub-groups at risk) for France, both as part of national surveillance (three-yearly reports) and internationally (production of indicators for WHO world reports on the subject).
• The resulting database also allows specific analyses on targeted aspects of maternal health.

The ENCMM method

To ensure that the study data are collected continuously, exhaustively and confidentially, the ENCMM is organised according to the following 3-stage procedure:

• Stage 1: Identification of “pregnancy-associated” deaths: multiple sources to guarantee exhaustive identification
  All deaths occurring during pregnancy or up to 1 year after its end, whatever the cause or mode of termination, are included. Four sources of identification are used:
  • 1) all the regional perinatal health networks participate in direct reporting in the event of the occurrence of a possible maternal death in an institution in their territory.
  • 2) death certificates, in collaboration with the Centre for Epidemiology of Medical Causes of Death (CépiDc). Since November 2022, electronic certification of deaths (currently being deployed) has enabled ENCMM coordination to be notified, as soon as the certificate has been completed, of any certification of a death in the context of pregnancy or childbirth (specific questions on the certificate).
  • 3) National databases of birth and death certificates are used to identify women who died in the year following a birth through linkage of databases;
  • 4) the PMSI (Programme de Médicalisation du Système d’Information) national hospital discharge database is used to identify hospital deaths of women in an obstetrical context.
• Stage 2: Documenting deaths: the task of the ENCMM assessors
  After informing the doctor(s) involved in the case, the EPOPé team notifies a pair of assessors, who will be responsible for gathering information (the woman’s history, the course of her pregnancy, the circumstances in which the event causing the death occurred and the treatment provided). This team is formed of volunteer clinicians and includes an obstetrician or midwife and an intensive care anaesthetist or a psychiatrist (depending on the context). The files are centralised by the EPOPé team and anonymised before being examined by the committee of experts.
• Stage 3: Review and classification of deaths
• This is the specific task of the National Expert Committee on Maternal Mortality (CNEMM). At plenary meetings (around 6 days a year), each death investigated is discussed collectively, based on all the available information. At the end of the collegial discussion, the committee reaches a consensus on :
  • 1) la cause du décès,
  • 2) le caractère « maternel » (lien causal avec la grossesse) ou non (lien temporel mais non causal) du décès.
  • Et s’il s’agit d’une mort maternelle : 3) l’adéquation des soins prodigués : les soins sont classés optimaux ou non optimaux
  • 4) le caractère évitable du décès, comme « non évitable », « possiblement évitable », ou « probablement évitable », selon l’existence de circonstances dont la correction aurait pu éviter l’issue fatale.

Regulatory authorisations

Since its creation, the ENCMM monitoring system has been approved by the Commission Nationale sur l’Informatique et les Libertés, and this approval has been updated over time. In 1995 (N°397377), then in 2009 (N°1373501) and in 2018 (decision DR-2018-157).

All the members of the ENCMM coordination team work in the EPOPé team (Obstetric Perinatal, and Paediatric Epidemiology Research Team), within the CRESS (Centre de Recherche en Épidémiologie et Statistiques), affiliated to Inserm (Institut National de la Santé et de la Recherche Médicale) and the Université Paris Cité.

Coordination :

Catherine
Deneux-Tharaux
Research Director at Inserm, Lead for the ENCMM

Aude Almeras
ENCMM national coordination midwife (lead)

Monica Saucedo
Coordination of ENCMM database and statistician

Véronique Tessier
ENCMM national coordination midwife

The National Expert Committee on Maternal Mortality (CNEMM) is responsible for analysing all maternal deaths at national level:

• confidential analysis, characterisation and classification of all maternal deaths in France, using data from the ENCMM;
• identifying the factors involved in these deaths;
• proposing preventive measures for maternal mortality;
• drawing up a triennial report on the epidemiological profile and causes of maternal mortality, and changes in these.

The CNEMM is composed of 20 members, including 18 qualified personalities appointed by decision of the Director General of Santé publique France and two ex officio members.

The following are ex officio members: An epidemiologist from the EPOPé team appointed by the Director of Inserm’s Public Health ITMO. An epidemiologist from the CépiDC appointed by the Director of the Inserm Public Health ITMO.

Are appointed as qualified personalities :
Six gynaecologists-obstetricians, six anaesthetists-reanimators, two midwives, one specialist in internal medicine, one specialist in cancer and pregnancy, two psychiatrists.

The ENCMM assessors

The ENCMM assessors are currently in practice clinicians, gynaecologists-obstetricians, midwives, intensive care anaesthetists and psychiatrists, throughout France, in a pool of around 220, who undertake this task on a voluntary basis.
For each death reported or identified, the survey coordination team traces the care path taken by the deceased patients in order to identify all the practitioners/services involved in their care (attending physician, follow-up maternity unit, delivery maternity unit, SAMU-SMUR, death department, etc). It then notifies a pair of assessors, who will be responsible for gathering information by consulting the woman’s medical documents and meeting with the teams who attended her. This team is made up of an obstetrician or midwife and an intensive care anaesthetist or psychiatrist, depending on the context of the death. The assessors are a key element of the system.

The ENCMM has two supervisory bodies, Inserm and Santé Publique France.

ENCMM partners

• Regional perinatal health networks
• CépiDC Inserm, https://www.cepidc.inserm.fr/
• Insee
• Professional societies: Collège national des gynécologues obstétriciens français, Club des anesthésistes réanimateurs en obstétrique and Société française d’anesthésie réanimation, le Collège national des sages-femmes, la Société française de médecine périnatale
• INOSS network https://www.npeu.ox.ac.uk/inoss