Placental pathology findings in unexplained pregnancy losses

There are approximately 5 million pregnancies per year in the United States, with 1 million ending in miscarriage (a loss occurring prior to 20 weeks of gestation) and over 20,000 ending in stillbirth at or beyond 20 weeks of gestation. As many as 50% of these losses are unexplained. Our objective was to evaluate the efficacy of expanding the placental pathology diagnostic categories to include the explicit categories of 1) dysmorphic chorionic villi and 2) small placenta to decrease the unexplained fraction. Using a clinical database of 1,256 previously unexplained losses at 6–43 weeks of gestation, the most prevalent abnormality associated with each loss was determined through examination of its placental pathology slides. Of 1,256 cases analyzed from 922 patients, there were 878 (69.9%) miscarriages and 378 (30.1%) antepartum stillbirths. We determined the pathologic diagnoses for 1,150/1,256 (91.6%) of the entire series, 777/878 (88.5%) of the miscarriages (<20 weeks’ gestation),..., Cases
A case series of 1,527 singleton pregnancies that ended in loss were identified from our tertiary-care consult service. Cases were excluded if the cause of loss could be elucidated from the clinical records alone, such as the presence of aneuploidies. Available demographic, clinical data, and gross description were abstracted from the clinical records when submitted with the consult request. Hematoxylin and eosin placental slides (no autopsy slides) were reviewed by the senior author (HJK). The analysis of this retrospective case series was approved by the Yale University Human Research Protection Program Institutional Review Board (protocol ID 2000029781).
Excluded cases
Cases with missing pathology slides, or an absence or insufficient number (fewer than five cross sections) of chorionic villi in the placental sample (Fig. 1) were excluded. The second exclusion criterion was an inability to date the clinical gestational age (GA), determined by the patient’s last menstrual period..., Microsoft Excel,