The Perinatal Postmortem Examination

Overview

Examination after perinatal death may be a difficult area for obstetricians and fetal medicine practitioners, many of whom may otherwise have little interaction with specialist pathology services. Therefore, the aim of this chapter is not to present detailed findings of issues in this field but rather to provide practical guidance for interaction of clinicians and pathologists to maximise utility of the various facets related to perinatal autopsy examination from consent through to technical aspects of the process itself and likely future advances in the area. Some aspects of the major categories of pathology that may be disclosed through postmortem investigations are also covered; detailed explanations of these conditions can be found in specialist embryology and perinatal pathology textbooks.

Introduction

Autopsy: Greek: ‘autos’ (self) + ‘optos’ (seen); or ‘autoptēs’ (eyewitness)

The role of the perinatal autopsy has come under increasing scrutiny from medical professionals and the public. Advances in medical imaging, increasing use of antenatal genetic testing and controversies associated with human tissue retention have combined with shifting population demographics and changing public attitudes, resulting in a reduction in acceptability of traditional autopsy and the encouragement of development of potentially more acceptable, contemporary approaches. Research into parental attitudes to autopsy has revealed that traditional postmortem examination is becoming less acceptable, especially among certain ethnic and religious groups, with autopsy rates falling in most countries ( Table 13.1 ). In addition to moral or religious reasons, parents have aversion to large incisions because of perceptions that the fetus or infant has ‘suffered enough’. From a clinical perspective, there is also a perception that autopsy reports vary in adequacy, alongside perceived difficulties in negotiating a highly specific informed consent process.

Although great insights into normal developmental processes and pathogenesis of congenital anomalies have resulted from perinatal autopsy findings, contemporary obstetric practice has changed, with introduction of widespread first and second trimester antenatal ultrasound screening resulting in accurate antenatal detection of a wide range of fetal abnormalities. Consequently, the role of examination of after death is also changing, with detection of unexpected major fetal anomalies now less frequent, but the range of antenatal fetal interventions and complexity of associated pathologies increasing. In addition, mechanistic data derived from many years of autopsy practice, which have provided improved understanding of numerous obstetric complications, is decreasingly likely to generate new insights in the absence of the introduction of novel approaches.

Although the concept of the autopsy examination as a means of medical audit and governance remains important (e.g., for terminations of pregnancy or after complex medical treatment ), the additional direct clinical benefit from autopsy examination of otherwise uncomplicated cases remains uncertain if there are no specific additional clinical questions to be addressed. The concept of examination after death must therefore develop in parallel with changes in antenatal care and technologies if it is to continue to make important contributions to research and clinical care. The concept of ‘investigation after death’ may therefore more accurately reflect the future of this approach, with personalised investigations performed targeted to address the specific issues of particular cases to improve the quality of information gained and increase parental acceptability.

Investigation after death is unusual in that many factors surrounding the decisions made and approaches used are primarily based around the wishes and expectations of the parents, and pathologists and clinicians alike should work together to shift the emphasis towards personalised investigation by providing the advantages and disadvantages of all options to address meaningful clinical questions (see Table 13.1 ).

Legal Aspects, Aims and Types of Autopsy

The precise arrangements for legal frameworks vary by country, but the principles described in this chapter for the United Kingdom are generally applicable to varying extents in most geographical locations. Autopsies can be broadly divided into those performed for medicolegal reasons (i.e., without parental or family consent at the behest of a legal representative, i.e., the coroner in the United Kingdom) and those for which consent is obtained from relatives. In adult practice, the consented hospital autopsy has largely disappeared over the past decade because of multiple complex reasons, which are not covered here. Conversely, in perinatal practice, consented autopsies are by far the most common investigation since because primary aim is to provide information for the parents regarding the underlying diagnosis and therefore recurrence rates and implications for future pregnancies. There has, however, also been a recent decline in the proportion of perinatal deaths undergoing consented autopsy investigation, although not as marked as with adult practice but with current overall consent rates of less than 50% for intrauterine fetal deaths.

Medicolegal postmortem investigations in the perinatal age range are relatively rare but may be indicated for deaths related to medical procedures, those in which negligence or criminal activity may have been contributing factors and for neonates who die suddenly and unexpectedly for whom a cause of death, and therefore death certificate, cannot be issued by the clinicians. In such cases, parental consent is not required, and conduct of the examination is on behalf of the coroner or police with several broad legal and epidemiological purposes:

• 1.

  Ascertain a cause, and if necessary, a mode of death.

• 2.

  Identify evidence of possible unlawful or unnatural causes of death.

• 3.

  Contribute to statistical information regarding population mortality.

These aims overlap with the legal requirements of the coroner, whose remit is to ‘establish the facts’ about the deceased, specifically:

• 1.

  The identity of the deceased

• 2.

  The time and place of death

• 3.

  The cause of death

• 4.

  The manner of death

Although unlawful death is uncommon in the perinatal setting, occasional cases of baby destruction or infanticide are still reported.

In contemporary practice, the aim of consented perinatal autopsy is primarily to provide potentially clinically important information for families regarding the underlying diagnosis or cause of death or the risk for recurrence or implications for siblings, to act as a medical audit tool for fetal medicine specialists or ultrasonographers, and to provide samples for genetic or other ancillary studies. Perinatal autopsy findings have historically contributed significantly to the understanding of human fetal development, the pathogenesis of fetal abnormalities and the pathogenesis of obstetric complications and continue to contribute to disease understanding and therapy development (e.g., descriptions of placental anatomical features in twin-to-twin transfusion syndrome in relation to outcomes). It is well established that the yield of clinically useful information is greater when perinatal autopsies are performed by specialist paediatric and perinatal pathologists compared with general pathologists, and it is therefore recommended that when possible, all perinatal autopsies should be performed in specialist centres. There are published guidelines for performance of such autopsies and requirements for staffing and training.

Consent for Investigation After Death

Consent for investigation after death should be viewed as a process, for which the ultimate aim is to establish permission to carry out the appropriate investigations to answer clinical questions posed and guide management of future pregnancies. In some circumstances, adequate information to answer such questions may be obtained through noninvasive means such as postmortem imaging and targeted biopsies (e.g., sampling of specific organ abnormalities such as suspected autosomal recessive polycystic renal disease), but in other cases, a full invasive autopsy may be required (e.g., in the setting of a complex postoperative perinatal death).

A useful set of guiding principles regarding consent includes:

• 1.

  Consent should be obtained by an experienced and appropriately trained professional, who should be respectful of the parents’ wishes.

• 2.

  The parents should be fully informed regarding all available options (including more limited approaches if available and applicable). The parents should be approached at an appropriate time, by a member of staff with whom they have a rapport, and should not be pressured into making a decision.

• 3.

  The parents should understand the specific procedure to which they are consenting, including current practice and recent developments. It should be noted that, for many parents, the possibility to contribute to research and therefore potentially help others in the future has been reported as a significant factor in parental decision making.

• 4.

  All parties should be made aware of the specific medicolegal frameworks (e.g., in the United Kingdom under the regulations of the Human Tissue Authority).

If one or more of the parents do not engage in the consent process or if they only wish for limited information to be given, this can make the consent procedure more difficult; in these circumstances, there should be clear documentation of what is discussed.

The Autopsy Procedure

The traditional perinatal autopsy consists of several distinct components, all of which are incorporated into an overall autopsy report. An overview of the processes involved and the types of pathologies that may be detected at each stage is provided next. To consent parents to the appropriate investigations, a working knowledge of the diagnostic yield provided by specific investigations is required by the practicing fetal medicine clinician and consent taker.