Single cell mapping of the human endometrium and first trimester decidua identifies distinct epithelial and stromal cell contributions to fertility [single cell RNA-seq]

Embryo implantation relies on the development of a receptive endometrium during the secretory phase of the menstrual cycle. Prior studies have attempted to define the window of embryo implantation within the secretory phase based on patterns of differentially expressed genes, but consensus surrounding this signature has not been achieved. We aim to examine the cell types that characterize the purported receptivity signature and identify new transcriptomic markers that define the mid-secretory endometrium through integrated bulk and single-cell RNA sequencing. Overall design: Single cell transcriptome profiling of endometrial biopsies from the proliferative, early secretory, mid secretory, and late secretory menstrual phases, and decidua from the first trimester of pregnancy.