Association between higher levels of serum estradiol and elevated levels of fibrin (fibrinogen) degradation products in late pregnancy following assisted reproductive technology treatment

Introduction: Assisted reproductive technology (ART) treatment is a risk factor for pregnancy-related venous thromboembolism (VTE). This study aims to explore the risk factors for elevated fibrin (fibrinogen) degradation products (FDPs), an indicator of hypercoagulability, in late pregnancy among women who underwent ART treatment. Materials and methods: This retrospective case-control study recruited 227 women who spontaneously conceived and 214 women who underwent ART treatment and gave birth. A subgroup analysis of the 214 pregnant women after ART treatment was performed. 156 women with elevated FDP levels and 58 women with normal FDP levels were designated as the case and control groups, respectively. Results: We found that ART treatment was a risk factor for higher FDP. After adjustments were made for confounders in the group of 214 women after ART treatment, fresh embryo transfer (adjusted odds ratio (aOR) = 3.33, 95% confidence interval (CI), 1.57-7.03) and > 10 oocytes retrieved (aOR = 2.09, 95% CI, 1.103.99) were associated with elevated FDP in late pregnancy. Serum estradiol (E2) levels on human chorionic gonadotropin (hCG) trigger day were higher in the high-FDP group. A positive correlation between E2 on hCG trigger day and FDP was found for both fresh embryo transfer (r=0.67, p < 0.001) and frozen embryo transfer (FET) (r = 0.53, p < 0.001). Conclusions: A higher E2 level on hCG trigger day is closely associated with dysfunction of coagulation and fibrinolysis in late pregnancy. When performing the thromboprophylaxis assessment during pregnancy, clinicians should pay more attention to patients who had previous ART treatment and had a high E2 level on hCG trigger day.