The key role of examining the placenta in establishing a probable cause for stillbirth

Autopsy is regarded as the "gold standard" to determine probable causes of stillbirths. However, autopsy is expensive and not readily available in low- and middle-income countries. Therefore, we assessed how the clinical cause of death is modified by adding placental histology and autopsy findings.

Data from the Safe Passage Study was used where 7060 pregnant women were followed prospectively. Following a stillbirth, each case was discussed and classified at weekly perinatal mortality meetings. This classification was later adapted to the WHO ICD PM system. Clinical information was presented first, and a possible cause of death decided upon and noted. The placental histology was then presented and, again, a possible cause of death, using the placental and clinical information, was decided upon and noted, followed by autopsy information. Diagnoses were then compared to determine how often the additional information changed the initial clinical findings.

Clinical information, placental histology, and autopsy results were available in 47 stillbirths. There were major amendments from the clinical only diagnoses when placental histology was added. Forty cases were classified as due to M1: complications of placenta, cord, and membranes, when placental histology was added compared to 7 cases with clinical classification only, and M5: No maternal condition identified decreased from 30 cases to 3 cases. Autopsy findings confirmed the clinical and placental histology findings.

Clinical information together with examination of the placenta revealed sufficient information to diagnose the most probable cause of death in 40 of 47 cases of stillbirth (85%).