Fetal Vascular Malperfusion as a Key Association of Dysmorphic Chorionic Villi in the Third Trimester.

OBJECTIVE: Dysmorphic chorionic villi (DCV) are histopathological findings typically associated with chromosomal abnormalities in early pregnancy loss. This study aimed to evaluate the clinical and pathological significance of DCV across all trimesters, particularly investigating their association with fetal vascular malperfusion (FVM) and adverse pregnancy outcomes in late gestation. METHODS: We retrospectively analyzed 100 placental cases with DCV diagnosed between June 2024 and July 2025. Cases were classified by trimester and assessed for maternal characteristics, fetal findings, and placental pathologies using standardized histomorphological criteria. RESULTS: DCV were identified across all trimesters, with highest prevalence in the second trimester (57%). FVM was significantly more common in third-trimester placentas (72.4%) compared to first (7.1%) and second (17.5%) trimesters (P < .001). Adverse fetal outcomes included medical termination (30%) and intrauterine fetal demise (25%), both confined to early trimesters. Chromosomal abnormalities were identified in 19% of cases, with trisomy 21 being most frequent (13%). CONCLUSION: DCV are not exclusive to early pregnancy loss but persist as clinically significant findings throughout gestation. The strong association between third-trimester DCV and FVM suggests these lesions may serve as prognostic histological markers for compromised fetoplacental perfusion. These findings support the need for standardized DCV criteria in placental classification systems and highlight the importance of genetic counseling when DCV are identified.