Recurrent pregnancy loss (RPL) is defined as the loss of two or more consecutive pregnancies before the 20 weeks of gestation. RPL affects about 1–2% of couples trying to conceive; however, the mechanisms leading to this complication are largely unknown. Our previous studies using comparative proteomics identified 314 differentially expressed proteins (DEPs) in the placental villous. In this study, we identified 5479 proteins from a total of 34 157 peptides in decidua of patients with early RPL (data are available via ProteomeXchange with identifier PXD023849). Further analysis identified 311 DEPs in the decidua tissue; and 159 proteins were highly expressed, whereas 152 proteins were lowly expressed. These 311 proteins were further analyzed by using Ingenuity Pathway Analysis. The results suggested that 50 DEPs played important roles in the embryonic development. Upstream analysis of these DEPs revealed that angiotensinogen was the most important upstream regulator. Furthermore, protein–protein interaction analysis of the embryonic development DEPs from the placental villous and decidua was performed in the STRING database. This study identified several proteins specifically associated with embryonic development in decidua of patients with early RPL. Therefore, these results provide new insights into potential biological mechanisms, which may ultimately inform RPL.

Summary sentence

Proteomic and functional analysis of decidua in patients with recurrent pregnancy loss.

Graphical Abstract