Maternal Immune Dynamics in Pregnancy

Pregnancy invokes a finely tuned sequence of immune adaptations that balance tolerance of the semiallogeneic fetus with protection against infection. In early gestation a transient pro-inflammatory milieu supports implantation, followed by an anti-inflammatory phase that facilitates placental growth, and culminating in a second pro-inflammatory wave that triggers labour. Both innate and adaptive arms of immunity undergo profound remodelling: uterine natural killer cells and decidual macrophages orchestrate vascular remodelling at the maternal–fetal interface, while populations of monocytes, dendritic cells and neutrophils in the periphery exhibit altered activation states. Adaptive shifts include expansion of regulatory T cells to enforce tolerance and modulation of T-helper cell subsets to prevent excessive inflammation. Disruption of these trajectories underlies conditions such as preeclampsia, fetal growth restriction and heightened vulnerability to viral pathogens. Recent advances in single-cell technologies and immunometabolic profiling have illuminated the cellular choreography of gestation and opened pathways for early diagnosis and targeted intervention.

Research from Nature Portfolio

Single-cell transcriptomics coupled with machine learning has revealed distinct circulating immune signatures in preeclampsia. Investigators identified a depletion of natural killer cell cytotoxic programmes alongside expansion of regulatory T cells, accompanied by heightened MHC class II activity in antigen-presenting cells. Two monocyte subsets marked by angiogenic and interferon-responsive gene expression emerged as potential drivers of vascular dysfunction, and cell-type-specific predictive models have been developed to flag preeclampsia before clinical onset.

Work on women with type 1 diabetes has demonstrated that metabolic disease perturbs normal gestational immune adaptations. Pregnant individuals with type 1 diabetes display an increased Th1/Th2 ratio, elevated activation of intermediate and non-classical monocytes and upregulated natural killer cell receptors. These alterations correlate with higher rates of preterm delivery and macrosomia, underscoring the interplay between glycaemic control and immune tolerance in pregnancy outcome.

Maternal Immune Dynamics in Pregnancy publication trend

The graph below shows the total number of articles in maternal immune dynamics in pregnancy across all publications each year (not limited to Nature Index journals).

Technical terms

Semiallogeneic: Tissues that carry both maternal and paternal antigens, requiring maternal immune tolerance.

Monocyte: A circulating innate immune cell that can differentiate into macrophages or dendritic cells.

Regulatory T cell (Treg): A subset of CD4+ T lymphocytes that suppress immune responses and maintain tolerance.

MHC class II: Cell-surface molecules on antigen-presenting cells that display peptides to CD4+ T cells.

Immunometabolism: The study of how cellular metabolic pathways influence immune cell function and fate.

Adenosine receptor A2B (A2BR): A G-protein-coupled receptor on immune cells activated by adenosine to modulate inflammatory responses.

References

1. Characterizing immune variation and diagnostic indicators of preeclampsia by single-cell RNA sequencing and machine learning. Communications Biology (2024).
2. Immunometabolic adaptation in monocytes underpins functional changes during pregnancy. iScience (2024).
3. Impact of the adenosine receptor A2BR expressed on myeloid cells on immune regulation during pregnancy. European Journal of Immunology (2024).
4. An immune clock of human pregnancy. Science Immunology (2017).
5. Immunological Adaptations to Pregnancy in Women with Type 1 Diabetes. Scientific Reports (2015).