Mechanisms of Maternal Immune Tolerance in Early Pregnancy

Maternal immune tolerance is essential for a successful pregnancy, as the maternal immune system must accept the semi-allogeneic fetus while maintaining defense against pathogens. Failure in this delicate balance can lead to complications such as recurrent miscarriage, preeclampsia, or implantation failure. Although several immune cell types, including T cells and regulatory pathways, are thought to play a role, the precise mechanisms underlying maternal immune adaptation during early pregnancy remain poorly understood.

This observational study investigates immunological changes occurring before and during early pregnancy and miscarriage in women undergoing in vitro fertilization (IVF). Blood samples will be collected at multiple predefined time points: prior to embryo transfer and during the first trimester of pregnancy as well as after miscarriage. These samples will be analyzed for immune cell composition, activation status, and cytokine profiles using advanced immunological assays. The longitudinal design allows for tracking dynamic changes in immune regulation from pre-implantation through early gestation.

The primary objective is to identify cellular and molecular signatures associated with maternal immune tolerance and successful implantation. Insights gained from this study may inform future strategies to predict and prevent pregnancy complications such as early miscarriage related to immune dysregulation.

• Transcriptional profiles of peripheral blood mononuclear cell (PBMC) subsets associated with pregnancy outcome (scRNA-seq) [Time frame: Before conception, week 6-7 of pregnancy, and following implantation failure or spontaneous miscarriage, up to 12 weeks of gestation]
• T-cell and B-cell receptor repertoire dynamics (TCR/BCR sequencing) [Time frame: Before conception, week 6-7 of pregnancy, and following implantation failure or spontaneous miscarriage, up to 12 weeks of gestation]