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Pregnant women with pre-existing mental health problems or medical conditions, such as high blood pressure, muscular or autoimmune conditions, are at increased risk of dying from pregnancy-related complications like blood clots, high blood pressure or haemorrhage.

Maternal deaths and “near misses” are rare in pregnancy, but there is potential to reduce them further. This major NIHR study used a variety of sources, including comprehensive national databases of cases and interviews with women and their partners, to try and determine the factors and scale of risk associated with these events.

It confirmed that almost half of all maternal deaths could be attributed to pre-existing medical or mental health conditions and further specified what these are. Other associated factors included older women, undergoing caesarean section, from Black or Indian ethnic background, and making less use of antenatal services.

The findings highlight the need for healthcare staff to recognise women at increased risk of pregnancy complications, and counsel them on their risk during pregnancy, including mode of delivery. Such women should also be represented when designing maternity services.

Why was this study needed?

In the UK maternal deaths are rare, occurring in three in every 100,000 childbirths (around 30 per year). Severe pregnancy complications needing urgent treatment and carrying risk of death - “near-miss” events – are also uncommon. These events still greatly impact women and their families. For example, the value of clinical negligence claims in 2014/15 was higher for obstetrics than any other specialty.

To understand how to improve services, we need to establish the role of pregnancy-related factors, maternal characteristics and pre-existing illness, how soon complications are identified, and interventions. Research into cases of deaths and “near misses” – severe complications is often limited to reviewing individual cases. Instead, this major NIHR study drew on cases in comprehensive UK-wide databases including the Confidential Enquiry into Maternal Deaths, and on women’s experiences.

The aim of this research was to describe best practice and identify maternity practices that may reduce risk of complications and prevent future deaths and near-misses.

What did this study do?

This study is part of a larger NIHR funded programme of work, while this signal features only the part looking at risk factors related to maternal deaths.

The study used a variety of methods. Data was analysed from national databases, including case reports of specific near-miss morbidities between 2005 and 2014. The experiences of women who had near-miss events and their partners were explored through 47 interviews over 4 years. Findings were compared with women without severe pregnancy complications.

The researchers explored the influence of socioeconomic status, ethnicity and maternal age, and identified factors associated with progression from severe illness to death. They also examined maternity care models that were informed by past patient experiences, compared to maternity services commissioned without patient input.

As data was observational and based on relatively few cases, it is not possible to fully account for all maternal and health-service factors that may have influenced the findings.

What did it find?

  • Pre-existing medical or mental health problems were the greatest contributor to risk of maternal death. Women who died from complications such as pregnancy-related high blood pressure (pre-eclampsia), blood clot in the lungs (pulmonary embolism), or blood infection (sepsis) were almost five times more likely than those who survived to have had existing problems (adjusted odds ratio [aOR] 4.82, 95% confidence interval [CI] 3.14 to 7.40). Associated problems included mental health, asthma, high blood pressure, autoimmune and muscular conditions, infections and blood disorders. Pre-existing medical or mental health conditions were estimated to account for almost half of all maternal deaths.
  • Maternal characteristics associated with risk of death were older age (35 years or over: aOR 2.36, 95% CI 1.22 to 4.56), and being of Black African or Caribbean (aOR 2.38, 95% CI 1.15 to 4.92). Indian ethnic background was specifically associated with risk of death as a direct result of pregnancy complications (aOR 2.70, 95% CI 1.14 to 6.43).
  • Additional factors associated with risk of death included poor uptake of antenatal care, substance misuse, previous pregnancy problems, and pregnancy-related high blood pressure in the current pregnancy.
  • Caesarean section is associated with risk of serious complications both in the current and future pregnancies. The number of previous caesareans, time interval since last pregnancy, and induction of labour may influence risk of rupture of the uterus.

What does current guidance say on this issue?

Maternity services are national and local priorities for service improvement and there is a strong focus on service quality.

Royal College of Gynaecologists’ standards from 2008 recommend multidisciplinary care is available for all women with pre-existing medical, psychological or social problems that may require specialist advice during pregnancy.

2014 NICE guidance recommends low-risk women be advised that a midwifery-led unit (or home birth if not first child) is particularly suitable. If a caesarean section is the safest option, for example because of another health condition, NICE recommends explaining the risks and benefits so women can make an informed decision.

What are the implications?

To further reduce maternal deaths and “near misses”, this research highlights that maternity service professionals need to recognise the increased risk for women with pre-existing medical or mental health conditions.

Women of older age and those with previous or planned caesarean section should be counselled about their risk and planned mode of delivery.

When designing or commissioning maternity services it is important to fully engage service users, including representation of minority ethnic groups and women who have experienced near-miss events, and their partners or families.


Citation and Funding

Knight M, Acosta C, Brocklehurst P, et al. Beyond maternal death: improving the quality of maternal care through national studies of ‘near-miss’ maternal morbidity. Programme Grants Appl Res. 2016;4(9).

This project was funded by the National Institute for Health Research Programme Grants for Applied Research (project number RP-PG-0608-10038).



NHSLA. NHS Litigation Authority report and accounts 2014/15.London: National Health Service Litigation Authority; 2015.

NICE. Caesarean section. CG132. London: National Institute for Health and Care Excellence; 2011.

NICE. Intrapartum care for healthy women and babies. CG190. London: National Institute for Health and Care Excellence; 2014.

Knight M, Kenyon S, Brocklehurst P, et al. Saving lives, improving mothers’ care - lessons learned to inform future maternity care from the UK and Ireland Confidential Enquiries into Maternal Deaths and Morbidity 2009–13. Oxford: Maternal, Newborn and Infant Clinical Outcome Review Programme, National Perinatal Epidemiology Unit, University of Oxford; 2014.

RCOG. Standards for Maternity Care. London: Royal College of Obstetricians and Gynaecologists; 2008.

Produced by the University of Southampton and Bazian on behalf of NIHR through the NIHR Dissemination Centre


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