Exploring the plasma proteome linked to corpus luteum presence and conception mode across pregnancy stages and postpartum.

Purpose: Observational data suggest that women conceiving without a corpus luteum are at higher risk of developing preeclampsia. While the underlying mechanisms remain unclear, the absence of corpus luteum-derived secretory products may be a contributing factor. This study investigates whether the plasma proteome differs between women who conceive with or without a corpus luteum and examines the relationship with mode of conception.

Methods: Plasma samples from 12 participants were collected at three time points: first trimester, third trimester, and postpartum. The cohort included women who conceived unassisted (UC) after infertility, via artificial cycle frozen embryo transfer (AC FET), or natural cycle frozen embryo transfer (NC FET). A total of 36 plasma protein samples were analyzed using mass spectrometry-based proteomics to compare the proteome of women who conceived with and without a corpus luteum, across different conception methods and pregnancy stages.

Results: In total, 528 proteins were quantified. No differentially expressed plasma proteins were identified between women with and without a corpus luteum. However, 15 proteins showed differential expression between UC and FET at all time points, with Bonferroni-corrected p < 9.47 × 10^-5 and FC ≥ |2|. Several altered proteins, including PAPPA and ANG, were linked to preeclampsia. SERPINA7 was differentially detected when comparing time points within the unassisted conception method. No significant differences were detected between AC FET and NC FET.

Conclusion: This pilot study revealed a unique proteomic signature associated with the mode of conception. The findings suggest biologically plausible candidate proteins for further testing. Validation in larger cohorts or with alternative proteome analysis technologies is needed.