Understanding the different types of maternity investigation that may be undertaken

Posted: 26/03/2025

Maternity investigations are important processes, designed to consider the safety and well-being of both mothers and newborns and to identify learning points. These investigations can help to identify and address issues that may arise during pregnancy, labour, and delivery. Such investigations may be undertaken at a local level, or as part of a nationwide initiative. 

The different types of investigation can be bewildering, not least because more than one type of investigation may be carried out concurrently, and they may be referred to by their abbreviated names. A number of the investigations have also changed over recent years.

It is important that families are given the opportunity to be involved in maternity investigations, if at all possible, and that they understand what investigations are taking place. 

This article seeks to explore the various types of maternity investigation, including serious untoward incident (SUI) investigations and serious incident reports (SIRs), the Patient Safety Incident Response Framework (PSIRF), Early Notification Scheme (ENS) investigations, Healthcare Safety Investigation Branch (HSIB) maternity investigations, and Maternity and Newborn Safety Investigations (MNSI), and to consider the purposes of these different lines of enquiry.

Serious untoward incident (SUI) investigations and serious incident reports (SIRs) 

Serious untoward incidents (SUI) are significant events that result in unexpected or avoidable harm to patients. Investigations can then lead to the production of serious incident reports (SIRs). When considering maternity care, SUIs could include incidents such as maternal deaths, stillbirths, or severe perinatal or neonatal injuries. These investigations aim to identify the root causes of incidents and to implement measures to try and prevent their recurrence. 

SUI investigations have typically been conducted by the healthcare providers involved, with a stated focus on transparency and learning from mistakes to improve patient safety. As they have been undertaken at a local level, there has been some variation between healthcare providers. Since the autumn of 2023, investigations are likely to take place under the Patient Safety Incident Response Framework (PSIRF), as below, although some trusts have been slower to introduce this than others.

Patient Safety Incident Response Framework (PSIRF)

The Patient Safety Incident Response Framework (PSIRF) has taken over from SIR investigations. PSIRF should be used whenever a patient safety incident is investigated, however it is important to note that not all patient safety incidents will be investigated under PSIRF. 

PSIRF differs from SIR in that it is much more flexible. PSIRF investigations do not occur because a particular incident triggers the need for an investigation; rather, the investigation is introduced because it is required to establish learning and improvement. This means that not every patient safety incident will be subject to an investigation under PSIRF. If a trust believes it knows what went wrong, and why the incident occurred, it may not investigate further. 

It should be noted that each NHS trust remains responsible for complying with the duty of candour, which is to be open and transparent with a patient or their family/loved one when a notifiable safety incident has occurred, whether or not the PSIRF is used.

Early Notification Scheme (ENS) investigations

The Early Notification Scheme (ENS) was introduced by NHS Resolution (which deals with claims against the NHS), in 2017, to expedite the investigation of severe brain injuries in newborns born after 1 April 2017. ENS requires NHS hospitals to report incidents where babies born at term (37 weeks’ gestation or beyond) in NHS hospitals suffer potential severe brain injuries within the first week of life (an investigation will also take place if the baby was therapeutically cooled and there is evidence of damage). 

The goal is to determine liability early on and to provide timely support to affected families. ENS investigations focus on identifying whether negligence occurred and, if so, ensuring that families receive appropriate compensation and apologies. The ENS investigation is not shared with families, but they should be told if liability is accepted. Since 1 April 2020, NHS Resolution will wait until MNSI (Maternity and Newborn Safety Investigations) has carried out its maternity investigation, and shared its report with them, before deciding if an ENS investigation should be undertaken.

Healthcare Safety Investigation Branch (HSIB) maternity investigations

The Healthcare Safety Investigation Branch (HSIB) became operational in April 2017, under the umbrella of NHS Improvement and, later, NHS England, and conducted independent, expert-led investigations into patient safety incidents across the NHS in England, with a focus on lessons from which NHS trusts could learn in order to reduce harm to patients. 

HSIB's maternity investigations focused on cases of intrapartum stillbirths, early neonatal deaths, and severe brain injuries in term babies. The aim was to identify systemic issues and make recommendations to improve maternity care. HSIB investigations were non-punitive and emphasised learning and improvement rather than assigning blame. The maternity investigations programme started in 2018 and ended on 30 September 2023, when the Maternity and Newborn Safety Investigations (MNSI) programme commenced in relation to births from 1 October 2023.

Health Services Safety Investigations Body investigations (HSSIB) (non-maternity investigations)

The Health Services Safety Investigations Body (HSSIB) is a statutory body that took over the responsibilities of HSIB on 1 October 2023. The transition to HSSIB aimed to enhance the independence and effectiveness of investigations, ensuring that lessons learned led to tangible improvements in patient safety. The investigations were also to be non-punitive and emphasise learning and improvement rather than assigning blame. It is important to note that the maternity investigation programme that was part of HSIB became the Maternity and Newborn Safety Investigations (MNSI) programme – see below – whereas non-maternity investigations now fall under the remit of HSSIB.

Maternity and Newborn Safety Investigations (MNSI)

The Maternity and Newborn Safety Investigations (MNSI) programme, which is hosted by the Care Quality Commission, commenced on 1 October 2023 (and replaced HSIB's maternity investigations), and is stated to be part of a national strategy to improve maternity safety across the NHS in England. MNSI investigates:

• maternal deaths (while the woman was pregnant or within 42 days of the end of the pregnancy from any cause related to, or aggravated by, the pregnancy or its management); and
• specific cases where the baby has reached term and there has been:
  • early neonatal death (the baby has died within the first week of life);
  • intrapartum stillbirth (when the baby was thought to be alive at the start of labour but was born with no signs of life);
  • severe brain injury in a term baby, diagnosed as occurring in the first seven days of life and when the baby was therapeutically cooled, or has been diagnosed with moderate to severe encephalopathy and certain criteria are met. 

The programme is to work closely with families, NHS trusts, and staff to conduct thorough investigations and make actionable safety recommendations. MNSI aims to enhance transparency and accountability in maternity care, ultimately improving outcomes for mothers and babies. However, MNSI does not seek to establish criminal or civil liability or carry out investigations from a legal or litigation perspective. This is different from ENS investigations.

Comment

Maternity investigations play an important role in considering the safety and well-being of mothers and newborns. By identifying and addressing the root causes of adverse incidents, these investigations are generally focused on preventing future occurrences and improving the quality of care. Through continuous learning and improvement, many of the programmes' stated aims are to create a safer and more supportive environment for childbirth, although the ENS scheme has a particular focus on considering liability and providing support in such cases.

We regularly represent families who have been affected by events occurring during late pregnancy and/or the births of their babies, as well as acting on behalf of the children themselves. If you would like to discuss a maternity investigation that is being undertaken, please get in touch.

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