Pregnancy outcomes and risk factors of decidual polyps in the first trimester after fresh cycle embryo transfer

OBJECTIVE: The aim of the present study was to analyze pregnancy outcomes among patients diagnosed with first-trimester decidual polyps (DPs) following fresh embryo transfer who underwent expectant management and to further explore risk factors associated with adverse pregnancy outcomes. METHODS: This retrospective cohort study included pregnant women who achieved singleton pregnancies following fresh embryo transfer at Peking University Third Hospital between January 2020 and April 2024 and were diagnosed with DPs during the first trimester. Based on first-trimester vaginal bleeding occurrence, patients were categorized into those with bleeding DPs (n = 143) and those with asymptomatic DPs (n = 163). RESULTS: DP width was significantly greater in the bleeding group than that in the asymptomatic group (0.60 ± 0.21 cm vs 0.53 ± 0.21 cm; P = 0.006); however, pregnancy outcomes between the two groups were similar (P = 0.402). Compared with the matched non-polyp bleeding group, the bleeding DPs group exhibited significantly higher rates of second-trimester miscarriage and cervical insufficiency (P < 0.001 and P = 0.011, respectively). DP width (odds ratio [OR] = 0.11, 95% confidence interval [CI]: 0.03-0.41; P = 0.001) and culture-guided therapy (OR = 4.14, 95% CI: 1.37-12.48; P = 0.033) were independent factors influencing live birth. CONCLUSION: The presence of DPs is associated with adverse pregnancy outcomes. Therefore, patients presenting with first-trimester vaginal bleeding or ultrasonographically suspected DPs should undergo thorough speculum examination and cervical secretion culture. Whenever available, culture-guided treatment should be implemented. Additionally, evaluation and active management of cervical insufficiency during pregnancy are recommended in these patients.