Human triploidy: association with partial hydatidiform moles and nonmolar conceptuses

Area of Science:

• Reproductive Pathology
• Human Genetics
• Developmental Biology

Background:

• Triploidy, a condition where a fetus has three sets of chromosomes, is a common cause of spontaneous abortion.
• Understanding the distinct pathological presentations of triploidy is crucial for accurate diagnosis and management.

Purpose of the Study:

• To retrospectively review the pathological features of spontaneous abortions with cytogenetically confirmed triploidy.
• To differentiate between molar and non-molar presentations within triploidy and analyze their clinical implications.

Main Methods:

• Retrospective analysis of nearly 100 cases of spontaneous abortion.
• Cytogenetic verification of triploid constitution.
• Pathologic review focusing on villous morphology and trophoblastic differentiation.

Main Results:

• 86% of triploid spontaneous abortions were partial hydatidiform moles, exhibiting focal syncytiotrophoblastic hyperplasia, villous edema, cistern formation, scalloped villi, and trophoblastic inclusions.
• 14% were non-molar, with normal or hypoplastic trophoblasts.
• Fetuses in both groups typically died around 8 weeks of gestational age.
• Partial moles showed prolonged intrauterine retention, while non-molar conceptuses often aborted earlier in the first trimester.

Conclusions:

• Triploidy presents with at least two distinct morphologic entities: partial hydatidiform moles and non-molar conceptuses.
• These entities differ in placental morphology and clinical presentation, particularly regarding gestational age at demise and intrauterine retention.
• Further investigation is needed to understand the etiologic factors underlying these divergent presentations in triploidy.