Adenomyosis, endometriosis of the uterus, is associated with an increased likelihood of abnormal endometrial molecular expressions thought to impair implantation and early embryo development, resulting in disrupted fertility, including the local effects of sex steroid and pituitary hormones, immune responses, inflammatory factors, and neuroangiogenic mediators. In the recent literature, all of the proposed pathogenetic mechanisms of adenomyosis reduce endometrial receptivity and alter the adhesion molecule expression necessary for embryo implantation. The evidence so far has shown that adenomyosis causes lower pregnancy and live birth rates, higher miscarriage rates, as well as adverse obstetric and neonatal outcomes. Both pharmaceutical and surgical treatments for adenomyosis seem to have a positive impact on reproductive outcomes, leading to improved pregnancy and live birth rates. In addition, adenomyosis has negative impacts on reproductive outcomes in patients undergoing assisted reproductive technology. This association appears less significant after patients follow a long gonadotropin-releasing hormone agonist (GnRHa) protocol, which improves implantation rates. The pre-treatment of GnRHa can also be beneficial before engaging in natural conception attempts. This review aims to discover adenomyosis-associated infertility and to provide patient-specific treatment options.

The implantation of human embryos is a complex process involving various cytokines and receptors expressed by both endometrium and embryos. However, the role of cytokines produced by a single embryo in successful implantation is largely unknown. This study aimed to investigate the role of IL-1β expressed in a single-embryo-conditioned medium (ECM) in embryo implantation. Seventy samples of single ECM were analyzed by a specially designed magnetic-beads-based microfluidic chip from 15 women. We discovered that IL-1β level increased as the embryo developed, and the difference was significant. In addition, receiver operator characteristic (ROC) curves analysis showed a higher chance of pregnancy when the IL-1β level on day 5 ECM was below 79.37 pg/mL and the difference between day 5 and day 3 was below 24.90 pg/mL. Our study discovered a possible association between embryonic proteomic expression and successful implantation, which might facilitate single-embryo transfer in the future by helping clinicians identify the embryo with the greatest implantation potential.

Preimplantation embryo development requires a tightly regulated microenvironment that is not fully reproduced by conventional static culture. We developed a polydimethylsiloxane-based microfluidic embryo co-culture platform integrating compartmentalized architecture with dynamic perfusion to simulate physiological conditions. The study included two stages. First, NIH/3T3 mouse fibroblasts were evaluated as helper cells under three culture conditions after transition to embryo culture medium. Helper-cell viability in the dynamic chip was 84.72%, compared with 71.91% after manual medium replacement in 24-well plates and 94.27% in the 24-well control group. Second, mouse embryos were cultured under four conditions: conventional 24-well plates, static microfluidic chip culture with co-culture, dynamic microfluidic chips without co-culture, and dynamic microfluidic chip co-culture. Blastocyst formation rates were 100.0% (9/9), 0.0% (0/6), 33.3% (3/9), and 55.5% (5/9), respectively. Because no inferential statistical analysis was performed, these proportions are interpreted descriptively. Nevertheless, the blastocyst formation in the microfluidic co-culture group supports the technical feasibility of integrating dynamic perfusion and helper-cell co-culture within a single platform. Further optimization and validation are required. This platform provides a foundation for future development of advanced embryo culture technologies including patient-specific endometrial co-culture systems in assisted reproduction, disease modeling, or drug development.