Trophoblast Retrieval from the Cervix (TRIC) Across Early Gestation: A Multi-Method Assessment of Extravillous Trophoblast Recovery.

Trophoblast retrieval from the cervix (TRIC) is a non-invasive approach that enables access to fetal-derived extravillous trophoblast (EVT) cells as early as the first trimester of pregnancy, offering a unique opportunity for early placental and fetal assessment. Although TRIC has been reported to be feasible between 5 and 20 weeks of gestation, systematic evaluation of EVT recovery across early gestation using complementary analytical approaches remains limited. This study aimed to provide a multi-method assessment of EVT recovery across early gestation. Endocervical samples were collected from 53 pregnant women between 5 and 19 weeks of gestation. EVT cells were isolated by immunomagnetic separation using human leukocyte antigen-G (HLA-G)-specific antibodies and assessed by β-hCG immunofluorescence, fluorescence in situ hybridization (FISH) and fluorescence-activated cell sorting (FACS). Immunofluorescence and FISH analyses showed no significant differences in β-hCG-positive or fetal cell proportions among gestational age groups, supporting stable TRIC-based recovery across early gestation. Exploratory FACS analyses identified HLA-G-positive trophoblast populations, including in samples obtained at 5 weeks of gestation. Because FACS analyses were performed in a subset of the cohort, these findings should be considered exploratory and require validation in larger cohort-wide studies. Overall, our findings support the feasibility of TRIC throughout early gestation and confirm the successful recovery of fetal-derived EVT cells from as early as 5 weeks of gestation. Further studies using larger cohorts and standardized quantitative approaches are required to more comprehensively characterize EVT recovery across early gestation and to optimize the application of TRIC in placental and prenatal research.