Severe maternal morbidity


Catherine Deneux-Tharaux (Research Director, Inserm), Gilles Kayem (Professor of Obstetrics and Gynecology)


If pregnancy and childbirth are physiological events in the woman’s life, they are sometimes complicated by severe morbid events, which may be life-threatening and potentially causing sequelae. These situations affect about 1% of women during pregnancy, childbirth or the postpartum. The relative importance of different causes varies, depending on the contexts and definitions adopted.

The interest in the study of severe maternal events is relatively recent, the main work of perinatal epidemiology and care policies having long focused on the health of the child. However, the current evolution of the profile of pregnant women – older, of increasing corpulence, more frequently carriers of chronic pathologies – as well as the controversies over certain obstetric practices – for example caesarean delivery – make it essential to have a better understanding of the factors involved. modulating the risk of severe maternal morbidity.

General objective

Our goal is to develop knowledge about the determinants of maternal health in its most pathological forms: mortality and severe maternal morbidity, with a particular interest for the determinants related to obstetric practices and the organization of care, to propose new practices or an improvement of current managementOur approach combines descriptive, etiological, and intervention evaluation objectives.

Main themes

Severe maternal complications are studied globally or by specific cause. Our research works are organized around 3 themes:

  1. Improve the measurement of severe maternal complications: study the validity of permanent databases to identify women with such complications; propose new definitions and methods of measurement. This research component can lead to the proposal of improved instruments, or to the simple characterization of the limits of existing instruments, which allows a relevant use. Beyond the objective of having optimal instruments for research, our work also seeks to decline these measures in the form of usable indicators for health surveillance, whenever possible and useful. This section concerns in particular maternal deaths, severe maternal morbidity considered globally, severe haemorrhage, placenta accreta.
  2. Identify the determinants of these complications: we target individual characteristics of women (eg social status, obesity), aspects of management of pregnancy or childbirth (notably the delivery route), organizational aspects of care (for example, the size or the human resources of maternity units) and the interactions between these categories. The impact of these determinants is studied at the different stages of the maternal morbidity continuum, from the early stage of complication until death, when relevant and data permitting.
  3. To evaluate the preventive and curative management of women with these severe complications:This axis combines:- an observational approach: the objective of this component is to describe the reality and the variability of the clinical practices related to maternal morbidity and mortality, to evaluate their conformity with the recommendations or the scientific literature, and to identify the factors modulating this adequacy, in terms of individual characteristics, and maternity units characteristics. – and an interventional approach whose objective is to test the impact of specific interventions aimed at reducing the incidence of these maternal complications, through randomized trials (cluster or individual randomization), testing hypotheses often generated by the results of observational studies conducted by the team.This component concerns in particular severe obstetric haemorrhage, placenta accreta, and intensive/critical care.

Main sources of data

  1. National Confidential Enquiry into Maternal Deaths (Enquête Nationale Confidentielle sur la Mortalité Maternelle, ENCMM) : Permanent national study since 1996 including all the maternal deaths in France, and coordinated by our team; 1200 cases included since 1996.
  2. EPIMOMS Study: A multi-regional French study conducted in 2013 that included 2,700 women with a severe maternal complication and a representative control sample of 3,600 women without serious complications; coordinated by our team.
  3. Paccreta Study: French multiregional study conducted in 2014-2016 and including 660 women at risk of and / or with placenta accreta, followed until 1 year after delivery; coordinated by our team.
  4. Randomised controlled trials: on the topic of postpartum haemorrhage, individual or cluster randomized trials, coordinated by our team or in collaboration. In addition to the specific objective of each trial, they allow secondary analysis of data for etiological or explanatory studies.
  5. Medico-administrative databases: Our team has developed expertise in the treatment and use of the PMSI national hospital discharge database for the study of maternal morbidity and mortality.

Main publications since 2011

Persons involved in this theme

Elie Azria (Obstetrician, Epidemiologist, Paris Descartes University), Marie-Pierre Bonnet (Anesthesiologist, Critical care specialist, Epidemiologist, Paris Descartes University), Nathalie Codet (Assistant), Anne Chantry (Midwife, Epidemiologist, Paris Descartes University), Coralie Chiesa (Project Manager),  Catherine Deneux-Tharaux (Epidemiologist, Inserm), Jeanne Fresson (Epidemiologist, Nancy University Hospital), François Goffinet (Obstetrician, Epidemiologist, Paris Descartes University), Gilles Kayem (Obstetrician, Epidemiologist, Pierre-et-Marie-Curie University), Geneviève Plu-Bureau (Gynecologist, Epidemiologist, Paris Descartes University),  Monica Saucedo (Project manager, statistician, Inserm), Priscille Sauvegrain (Midwife, Sociologist, Pierre-et-Marie-Curie University),Thomas Schmitz (Obstetrician, Paris Diderot University), Aurélien Seco (Statistician), Diane Korb (doctoral student), Ayesha Siddiqi (doctoral student)

Main collaborations


  • Regional Perinatal Networks and their national federation
  • Clinical Research Unit, Paris Centre
  • Pôle IMER des Hospices Civils de Lyon, EA 4129 Université Lyon1
  • Santé Publique France and CépiDC (on measurement questions and indicators in the medico-administrative databases)


  • INOSS (International Network of Obstetric Survey Systems): essentially European network of organizations conducting prospective population-based studies of rare, serious illnesses in pregnancy and childbirth.
  • National Perinatal Epidemiology Unit, Oxford, UK.
  • Reproductive Epidemiology and Adolescent Health Team of the National School of Public Health, Fio Cruz, Rio, Brésil.
  • Europeristat group.