Background: Endometriosis and uterine fibroids are benign conditions frequently linked to subfertility/infertility. Recent research has highlighted the importance of epithelial–mesenchymal transition between embryonic and endometrial cells in the context of embryo implantation. Additionally, the adverse endometrial environment during implantation has been proposed as a mechanism contributing to infertility in endometriosis. Nevertheless, the role of cadherin molecule alterations in relation to endometrial receptivity and embryo invasion remains a subject of controversy. Methods: We investigated the expression patterns of E-cadherin and N-cadherin in the endometria of women with ovarian endometrioma or uterine fibroids and assessed whether they differed from those of healthy women. We enrolled 17 women with ovarian endometrioma, 16 with uterine fibroids, and 6 healthy women. Endometrial tissues were obtained at the mid-secretory phase on days 19–24 of the menstrual cycle. The E-cadherin and N-cadherin mRNA and protein expression levels were measured using quantitative reverse transcriptase polymerase chain reaction and Western blot analysis, respectively. Results: The E-cadherin and N-cadherin mRNA expression levels were higher and lower, respectively, in the endometrium of women with ovarian endometrioma than in those of the controls. In the endometrium of women with uterine fibroids, similar patterns with higher E-cadherin and lower N-cadherin levels were observed compared with that of the controls. Protein expression showed similar patterns. Conclusions: Our findings revealed higher E-cadherin expression and lower N-cadherin expression in the endometria of women with infertility-related diseases than in those of healthy women in the mid-secretory phase. This suggests a resistance to endometrial receptivity, potentially reflecting mesenchymal–epithelial transition properties.

Infertility is a complex disease characterized by extreme genetic heterogeneity, compounded by various environmental factors. While there are exceptions, individual genetic and genomic variations related to infertility are typically rare, often family-specific, and may serve as susceptibility factors rather than direct causes of the disease. Consequently, identifying the cause of infertility and developing prevention and treatment strategies based on these factors remain challenging tasks, even in the modern genomic era. In this review, we first examine the genetic and genomic variations associated with infertility, and subsequently summarize the concepts and methods of preimplantation genetic testing in light of advances in genome analysis technology.

Cell-free DNA (cfDNA) screening for normal fetal aneuploidy has been widely adopted worldwide due to its convenience, non-invasiveness, and high positive predictive rate. We retrospectively evaluated 9327 Korean women with single pregnancies who underwent a non-invasive prenatal test (NIPT) to investigate how various factors such as maternal weight, age, and the method of conception affect the fetal fraction (FF). The average FF was 9.15 ± 3.31%, which decreased significantly as the maternal body mass index (BMI) increased (p < 0.001). The highly obese group showed a ‘no-call’ rate of 8.01%, which is higher than that of the normal weight group (0.33%). The FF was 8.74 ± 3.20% when mothers were in their 40s, and lower than that when in their 30s (9.23 ± 3.34, p < 0.001) and in the natural pregnancy group (9.31% ± 3.33). The FF of male fetuses was observed to be approximately 2.76% higher on average than that of female fetuses. As the gestational age increased, there was no significant increase in the fraction of fetuses up to 21 weeks compared to that at 10–12 weeks, and a significant increase was observed in the case of 21 weeks or more. The FFs in the NIPT high-risk result group compared to that in the low-risk group were not significantly different (p = 0.62). In conclusion, BMI was the factor most associated with the fetal fraction. Although the NIPT is a highly prevalent method in prenatal analysis, factors affecting the fetal fraction should be thoroughly analyzed to obtain more accurate results.

Background: Trophoblast retrieval and isolation from the cervix (TRIC) has emerged as a promising alternative to invasive prenatal diagnostic procedures. However, contamination by maternal immune cells remains a major challenge that may compromise trophoblast purity and the reliability of downstream fetal genetic analyses. Methods: Maternal immune cells were selectively depleted by immunomagnetic sorting using antibodies targeting CD45 or CD56. The remaining cells were subsequently enriched for HLA-G-positive trophoblasts and characterized by immunofluorescence and gene-expression analyses using CD45, CD56, HLA-G, cytokeratin 7 (CK7), and β-human chorionic gonadotropin (β-hCG). Results: Compared with CD45-mediated depletion, CD56-mediated depletion demonstrated more efficient removal of maternal immune cells, as indicated by significantly reduced CD56 expression. CK7 expression showed an increasing trend following CD56 depletion, whereas β-hCG expression remained largely unchanged. Immunofluorescence analysis further demonstrated a significant increase in the proportion of CK7⁺/β-hCG⁺ trophoblast cells after CD56 depletion. Conclusions: Among the evaluated depletion strategies, CD56-mediated depletion demonstrated a more favorable profile for trophoblast-associated characteristics than CD45-mediated depletion, suggesting its potential contribution to further methodological optimization of trophoblast isolation in TRIC-based noninvasive prenatal genetic testing.