Traditional Chinese medicine syndrome patterns in immune-related recurrent spontaneous abortion: A cross-sectional observational study based on cluster analysis

Recurrent spontaneous abortion (RSA) arises from a multifactorial etiology, frequently associated with immune system irregularities. The immunopathological mechanisms underlying miscarriage differ, and immune-mediated abortion can be categorized into autoimmune RSA and alloimmune RSA. Traditional Chinese medicine (TCM) has unique advantages in treating immune-related RSA, but currently lacks systematic studies on TCM syndrome differentiation. This study aims to explore the TCM syndrome characteristics of immune-related RSA patients using cluster analysis, revealing the clinical manifestations and features of different syndromes, to provide theoretical evidence for clinical TCM diagnosis and treatment. This study designed a TCM syndrome information collection form for immune-related RSA and conducted a clinical epidemiological survey of 244 immune-related RSA patients, collecting symptoms, tongue and pulse information, and performing frequency analysis. A hierarchical cluster analysis was performed on variables, using the between-groups linkage method and Squared Euclidean distance to identify distinct syndrome patterns. Based on the clustering results and TCM theory, relevant syndromes were summarized, and the relationship between syndrome distribution, age, and number of miscarriages was further analyzed. The results show that the distribution of syndromes in immune-related RSA is as follows: kidney deficiency and blood-stasis syndrome (57.4%), spleen-kidney yang deficiency syndrome (18.8%), kidney deficiency and internal heat syndrome (12.3%), and kidney deficiency with damp-heat syndrome (11.5%). As age advances, the prevalence of kidney deficiency and blood-stasis syndrome notably escalates. Similarly, an increase in the number of miscarriages correlates with a higher incidence of this syndrome, especially in patients who have experienced more than 3 miscarriages. This study identifies the TCM syndrome classification pattern for immune-related RSA, highlighting that "deficiency," "heat," and "stasis" are the primary etiological factors, with kidney deficiency and blood-stasis syndrome being the most prevalent. The results offer empirical support for clinical TCM syndrome differentiation and treatment, while also establishing a theoretical foundation for TCM-based therapeutic strategies for immune-related RSA.