SDC1 and Infertility: During the proliferative phase of the endometrium, the presence of CD-138+ cells has been identified as an adverse indicator for pregnancy outcomes in fresh IVF/intracytoplasmic sperm injection (ICSI) cycles, with a specific quantitative threshold [16]. Although endometrial plasma cells, which express CD-138, are present in half of the general infertile population, they do not serve as predictive markers for clinical pregnancy, clinical pregnancy loss, or live birth rates when present at low levels [4].