AbstractInflammation is of critical importance in successful implantation during pregnancy. However, the establishment of maternal immune tolerance towards semi‐allograft foetus is more exigent and is achieved predominantly by human leukocyte antigen‐G (HLA‐G) isoforms with a special emphasis on soluble HLA‐G5 (sHLA‐G5). Constant inflammation and lack of resolution by anti‐inflammatory milieu, due to aberrant expression of critical immunoregulatory molecules such as sHLA‐G5 and dysfunctional T helper cells 1 and 2 (Th1‐Th2) cytokine shift, can lead to adverse pregnancy outcomes including recurrent pregnancy loss (RPL). Serum samples of 270 pregnant women (135 healthy parous and 135 with a history of RPL) were evaluated for the concentrations of sHLA‐G5, interleukin‐4 (IL‐4) and tumour necrosis factor‐alpha (TNF‐α) using sandwich enzyme‐linked immunosorbent assay (ELISA) and found elevated levels of sHLA‐G5 and IL‐4 in controls and higher TNF‐α levels and TNF‐α:IL‐4 ratio in patients (P < .05). Stratified data analysis based on the time of sample collection, that is the first and second trimesters exhibited higher sHLA‐G5 and IL‐4 in both first and second trimesters in controls than patients, while they displayed lower levels concerning TNF‐α and TNF‐α:IL‐4 ratio (P < .05). However, within patients and controls in the first or second trimesters, there was a significant variation concerning sHLA‐G5 alone. Further, the outcome of pregnancies studied in the present investigation revealed a significant elevation in sHLA‐G5 levels among women with successful pregnancies compared with women who experienced pregnancy loss, therefore, concluding the potential application of sHLA‐G5 isoform as a marker in assisting improved pregnancy outcomes.