Intricate Immunological Changes that Occur During Pregnancy: A Chronological Study

Researchers from Stanford University School of Medicine have elucidated for the first time the intricate immunological changes that occur during pregnancy, as a chronological study.¹ It is well known that pregnancy poses an interesting dilemma to the human body. Immune function must be dampened in certain areas, so as not to abort the fetus, which is, after all, a foreign object, while simultaneously continuing to protect against external pathogens. We know, for example, that T cell and B cell frequencies are decreased during pregnancy.² Also, the ability of CD4+ T cells to make T helper cells is diminished, while aspects of the innate immune system (natural killer cells and dendritic cell lines) are increased when stimulated with viral particles during pregnancy.² But there has yet to be a firm chronological timeline given to these changes.

Importance of an Immunological Clock of Pregnancy

The importance of an immunological clock of pregnancy, according to the research study, is to isolate where-in pregnancy abnormalities are arising, as well as determine risk of preterm births. Currently, there are inadequate tools for determining if pregnancies will go to term or not. The research does suggest that pregnancy follows a very precise immunological pattern in healthy pregnancies, and that it may be used to determine whether the immunological clock in a given pregnancy is running fast or slow – and the likelihood of premature delivery.

The Study

The study looked at 18 women, all whom had full-term pregnancies. Women gave 4 blood samples over the course of their pregnancies, and 6-weeks after delivery. A sample of 10 additional women was taken to validate findings. Using mass cytometry, the types of immune cells, signaling pathways, activity of each cell line, and mannerisms of cell reactivity was assessed. Gestational age, rather than trimester was used as a model for blood sample analysis, in order to account for a more accurate time of pregnancy.

Next Step in This Line of Research

The next step in this research is to repeat the same study including women who all have premature births and find patterns which seem to correlate with these changes in pregnancy.

Sources

1. Aghaeepour N, Ganio E, Mcilwain D, et al. An Immune Clock of Human Pregnancy. Science Immunology, 01 Sept. 2017. DOI: 10.1126/sciimmunol.aan2946
2. A. W. Kay, J. Fukuyama, N. Aziz, et al. Enhanced natural killer-cell and T-cell responses to influenza A virus during pregnancy. Proc. Natl. Acad. Sci. U.S.A. 111, 14506–14511 (2014).

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Node Smith, ND, is a naturopathic physician in Portland, OR and associate editor for NDNR. He has been instrumental in maintaining a firm connection to the philosophy and heritage of naturopathic medicine among the next generation of docs. He helped found the first multi-generational experiential retreat, which brings elders, alumni, and students together for a weekend camp-out where naturopathic medicine and medical philosophy are experienced in nature. Four years ago he helped found the non-profit, Association for Naturopathic ReVitalization (ANR), for which he serves as the board chairman. ANR has a mission to inspire health practitioners to embody the naturopathic principles through experiential education. Node also has a firm belief that the next era of naturopathic medicine will see a resurgence of in-patient facilities which use fasting, earthing, hydrotherapy and homeopathy to bring people back from chronic diseases of modern living; he is involved in numerous conversations and projects to bring about this vision.