Placental Findings Contributing to Perinatal Death: A 15-Year Retrospective Review from a Teaching Hospital in Thailand

Criteria for placental examination for obstetrical and neonatal providers

Pathologic examination of the placenta can provide insight into likely (and unlikely) causes of antepartum and intrapartum events, diagnoses with urgent clinical relevance, prognostic information for mother and infant, support for practice evaluation and improvement, and insight into advancing the sciences of obstetrics and neonatology. Although it is true that not all placentas require pathologic examination (although alternative opinions have been expressed), prioritization of placentas for pathologic examination should be based on vetted indications such as maternal comorbidities or pregnancy complications in which placental pathology is thought to be useful for maternal or infant care, understanding pathophysiology, or practice modifications. Herein we provide placental triage criteria for the obstetrical and neonatal provider based on publications and expert opinion of 16 placental pathologists and a pathologists' assistant, formulated using a modified Delphi approach. These criteria include indications in which placental pathology has clinical relevance, such as pregnancy loss, maternal infection, suspected abruption, fetal growth restriction, preterm birth, nonreassuring fetal heart testing requiring urgent delivery, preeclampsia with severe features, or neonates with early evidence of multiorgan system failure including neurologic compromise. We encourage a focused gross examination by the provider or an attendant at delivery for all placentas and provide guidance for this examination. We recommend that any placenta that is abnormal on gross examination undergo a complete pathology examination. In addition, we suggest practice criteria for placental pathology services, including a list of critical values to be used by the relevant provider. We hope that these sets of triage indications, criteria, and practice suggestions will facilitate appropriate submission of placentas for pathologic examination and improve its relevance to clinical care.

Classification of stillbirth by the International Classification of Diseases for Perinatal Mortality using a sequential approach: A 20-year retrospective study from Thailand

AIM

The International Classification of Diseases for Perinatal Mortality (ICD-PM) is a system for recording causes of perinatal death. In this system, placental pathology is considered a "maternal condition" and this category does not cover the spectrum of placental pathology that can impact on perinatal death. The aim of the study was to apply a wider spectrum of placental pathology as a separate parameter for classifying death in the ICD-PM.

METHODS

All autopsy reports at a single institution over a 20-year period (2001-2020) were reviewed. Causes of stillbirth were analyzed in a sequential manner: step 1, clinical history and laboratory results; step 2, placenta; and step 3, autopsy; and classified at each step according to the ICD-PM.

RESULTS

The review identified 330 cases, including 126 antepartum and 204 intrapartum deaths. Step 1 identified a cause in 176 (86%) intrapartum deaths and 64 (51%) antepartum deaths. The addition of placental pathology (step 2) changed the cause of death in 12% of cases, with causes now identified in 190 (93%) intrapartum and 89 (71%) antepartum deaths. Adding step 3 did not identify any additional causes of death.

CONCLUSION

The accuracy of the ICD-PM classification is dependent on the data available. Placental pathology made a significant difference in assigning causes of death in our series, stressing the importance of placental examination. Determination of the cause of death based on clinical history and laboratory data alone may be inaccurate, and less useful for comparative studies and planning prenatal care.