First-trimester miscarriage: A histopathological classification proposal

Rosete Maria Amorim Novais Nogueira Cardoso; Pedro Luís Novais Nogueira Cardoso; Ana Paula Azevedo; Jesús Siles Cadillá; Maria Graça Ribeiro Oliveira Rodrigues Amorim; Marcos Emanuel Rocha Gomes; Jorge Manuel Nunes Correia Pinto

doi:10.1016/j.heliyon.2021.e06359

First-trimester miscarriage: A histopathological classification proposal

Heliyon. 2021 Mar 8;7(3):e06359. doi: 10.1016/j.heliyon.2021.e06359. eCollection 2021 Mar.

Authors

Rosete Maria Amorim Novais Nogueira Cardoso^{1

2

3}, Pedro Luís Novais Nogueira Cardoso⁴, Ana Paula Azevedo³, Jesús Siles Cadillá^{3

5}, Maria Graça Ribeiro Oliveira Rodrigues Amorim⁶, Marcos Emanuel Rocha Gomes³, Jorge Manuel Nunes Correia Pinto^{1

2}

Affiliations

¹ School of Medicine, University of Minho, Surgical Sciences Domain Research, Campus de Gualtar, 4710-057, Braga, Portugal.
² Life and Health Sciences Research Institute (ICVS), ICVS/3B's - PT Government Associate Laboratory, Campus de Gualtar, 4710-057, Braga/Guimarães, Portugal.
³ CGC Genetics-Unilabs, Embryo-fetal Pathology Laboratory, R. Sá da Bandeira, 706, 1º, 4000-431, Porto, Portugal.
⁴ Unilabs, Molecular Laboratory, R. Sá da Bandeira, 706, 1º, 4000-431, Porto, Portugal.
⁵ Centro Hospitalar Universitário do Algarve, Pathology Laboratory, R. Leão Penedo, 8000-386, Faro, Portugal.
⁶ Centro Hospitalar de Tâmega Sousa, Prenatal Diagnosis Department, Hospital Tâmega Sousa, Av. Padre Américo, 210, 4564-007, Penafiel, Portugal.

Abstract

Background: Histopathology of first-trimester abortion products may be useful in document an intrauterine pregnancy, identifying an important pathology affecting the mother or the embryo and diagnosing conditions that are likely to recur in future pregnancies or that explain the adverse fetal outcome. Relevant information provided by histology is essential to determine the cause and to guide the patients with early pregnancy failure.

Aims: Histopathological classification proposal in first-trimester miscarriage.

Methods: Published pathological criteria in first-trimester abortion specimens were collected, standardized and focused into a comprehensive diagnosis. The idea was to create a comprehensive classification related to major pathophysiological processes. Thus, the histological criteria were grouped into 7 categories: i. Changes suggesting aneuploidy (CSA) or metabolic storage disease; ii. Embryo anomaly (EA); iii. Multifactorial (MF) causes; iv. Maternal causes (MC); v. Gestational trophoblastic disease, such as hydatidiform mole (HM) and non neoplastic lesions and neoplasms; vi. Ectopic pregnancy; vii. Other. So, a 6-years retrospective study of first-trimester spontaneous miscarriage were reviewed. Two groups were created: i. Study group include specimens with pathological diagnosis; ii. Control group incorporate specimens with pathological diagnosis and additional genetic study in order to validate pathological criteria.

Results: Pathological criteria concordance between inter-observers was generally good, with an excellent correlation in EA and HM categories. Despite greater inter-observer disagreement in the CSA and MC categories the correlation with the genetic results was very positive.

Conclusion: A standardized, reproducible and biologically comprehensive histopathological classification may improve fetal follow-up and couple's management.

Keywords: Chorionic villi morphology; Classification proposal system; Clinical relevance; Embryo pathology; First-trimester miscarriage; Histopathology.