Objective: Di-2-ethylhexyl phthalate (DEHP) and bisphenol A (BPA) are common endocrine-disrupting chemicals (EDCs) that are associated with preterm birth (PTB). However, the molecular and cellular mechanisms of these chemicals are still unclear. Accordingly, in this study, we evaluated whether EDCs were associated with PTB. Methods: Five-week-old virgin female ICR mice were administered a bolus of 100 L sunflower seed oil (100%), DEHP, or BPA by intraperitoneal injection every 3 days for 3 weeks. Formalin-fixed paraffin-embedded uterine sections were stained with hematoxylin and eosin and immunohistochemical staining. Human myometrial tissues were obtained from premenopausal women (n = 5) with uterine fibroids at the time of elective hysterectomy. Proteins and RNA were extracted from mouse uterine tissues and human myometrial cells using protein extraction solution and Tri-RNA reagent, respectively. Data analysis was conducted by using western blotting and quantitative real-time polymerase chain reaction. Results: Notably, in human myometrial cells treated with DEHP and BPA, the expression levels of cyclooxygenase-2, oxytocin receptor, and connexin 43, which are related to the onset of labor pain and delivery, were obviously increased. Also, they showed significant increases in mRNA levels of pro-inflammatory cytokines, including tumor necrosis factor-, interleukin-1, and interleukin-6. Meanwhile, progesterone receptor-A expression was specifically increased in samples obtained from mice treated with DEHP. Conclusion: Overall, these findings showed that maternal exposure to DEHP and BPA during pregnancy activated inflammatory signaling and induced the expression of uterine activation proteins through the decreased uterine responsiveness to the relaxatory effects of progesterone, providing insights into the association between EDCs exposure and obstetric complications.