INTRODUCTION: To evaluate the association between the systemic immune-inflammation index (SII) measured on the day of embryo transfer (ET) and clinical pregnancy outcomes in patients with recurrent implantation failure (RIF) undergoing euploid frozen–thawed embryo transfer (FET) cycles.
METHODS: This retrospective cohort study included 160 RIF patients who underwent PGT-A-confirmed euploid blastocyst transfer between January 2022 and December 2024. SII was calculated as platelet count × (neutrophil count / lymphocyte count) using blood samples obtained on the morning of ET. Multivariable logistic regression and receiver operating characteristic (ROC) curve analyses were performed to evaluate predictive factors
RESULTS: Clinical pregnancy was achieved in 29.4% (47/160) of patients. SII levels were lower in patients with clinical pregnancy compared to those without (321.4 ± 115.0 vs. 448.6 ± 166.8; p=0.009). Each 100-unit decrease in SII was independently associated with an increased likelihood of clinical pregnancy (OR: 1.29; 95% CI: 1.03–1.62; p=0.025). ROC analysis identified an optimal cut-off value of 380 (AUC=0.68). Clinical pregnancy rates were higher in the low SII group (<380) compared to the high SII group (40.3% vs. 20.5%; p=0.009).
DISCUSSION AND CONCLUSION: SII measured on the day of ET is an independent predictor of clinical pregnancy in euploid FET cycles among RIF patients and may serve as a practical, non-invasive marker for risk stratification.

Background: Umbilical vein varix (UVV) is a rare umbilical cord abnormality associated with adverse perinatal outcomes, including fetal growth restriction (FGR), although its clinical significance remains unclear.
Case Presentation A 31-year-old gravida 2 woman was diagnosed with intra-abdominal UVV at 20 weeks of gestation. Serial ultrasonography demonstrated progressive enlargement of the varix from 8.4 mm to 15.3 mm at 26 weeks, followed by stabilization. Fetal growth progressively declined, and FGR was diagnosed at 26 weeks of gestation when the estimated fetal weight fell to the 2nd percentile, despite preserved conventional Doppler findings. Serial evaluation suggested a visual inverse temporal relationship between varix size and fetal growth percentile. The pregnancy was closely monitored, and a healthy female infant weighing 2349 g was delivered at 37 weeks without immediate neonatal complications.
Conclusion: Progressive enlargement of umbilical vein varix may be associated with the subsequent development of fetal growth restriction, even in the presence of preserved conventional Doppler parameters, and could represent a potential early imaging marker requiring close surveillance. These findings underscore the potential value of serial ultrasonographic monitoring of varix size, flow characteristics, and fetal growth for individualized antenatal management in pregnancies complicated by UVV.