First-trimester miscarriage: A histopathological classification proposal

Area of Science:

• Reproductive Medicine
• Pathology
• Genetics

Background:

• Histopathology of first-trimester abortion products is crucial for diagnosing intrauterine pregnancies, maternal/embryonic pathologies, and recurrent conditions.
• Histological findings guide the determination of causes and management of early pregnancy failure.

Purpose of the Study:

• To propose a comprehensive histopathological classification for first-trimester miscarriages.

Main Methods:

• Collected and standardized published pathological criteria for first-trimester abortion specimens.
• Developed a 7-category classification system based on pathophysiological processes (e.g., aneuploidy, embryo anomaly, maternal causes, gestational trophoblastic disease).
• Conducted a 6-year retrospective study, comparing a study group (pathological diagnosis) with a control group (pathological diagnosis + genetic study).

Main Results:

• Generally good inter-observer concordance for pathological criteria, with excellent correlation for Embryo Anomaly (EA) and Hydatidiform Mole (HM).
• Despite higher inter-observer disagreement in Changes Suggesting Aneuploidy (CSA) and Maternal Causes (MC) categories, correlation with genetic results was positive.
• The proposed classification demonstrated good reproducibility and validity.

Conclusions:

• A standardized, reproducible, and biologically comprehensive histopathological classification system can enhance fetal follow-up.
• This classification aids in improved management strategies for couples experiencing early pregnancy failure.