Comparative Predictive Value of First-Trimester Crown-Rump Length and Nuchal Translucency Discordance for Fetal...

Background/Objectives: Twin pregnancies carry substantially elevated perinatal risks, yet tools for first-trimester risk stratification remain limited. This retrospective cohort study evaluated the predictive value of crown-rump length (CRL) and nuchal translucency (NT) discordance for adverse perinatal outcomes in 184 twin pregnancies at Ankara Etlik City Hospital, Turkey (October 2022-January 2024). Methods: CRL discordance ≥ 10% and NT discordance ≥ 20% were assessed for a birth-weight-based proxy of fetal growth restriction (FGR), preeclampsia, and neonatal outcomes using multivariable logistic regression adjusted for chorionicity, body mass index (BMI), and conception mode. Results: CRL discordance ≥ 10% was independently associated with the birth-weight-based FGR proxy (adjusted odds ratio [OR] 7.79, 95% confidence interval [CI] 3.95-20.12, p < 0.001; area under the curve [AUC] 0.736). NT discordance ≥ 20% was also independently associated with the birth-weight-based FGR proxy (OR 3.74, 95% CI 1.91-8.39, p < 0.001; AUC 0.612). Both parameters were associated with lower Apgar scores. IVF conception was independently associated with preeclampsia in an exploratory analysis (OR 5.31, 95% CI 1.41-28.66, p = 0.016). Continuous modelling confirmed a dose-response relationship for CRL discordance (OR per 1% increase = 1.20, 95% CI 1.13-1.32). Conclusions: These findings suggest that first-trimester CRL discordance may provide useful early prognostic information for birth-weight-based adverse growth outcome in twin pregnancies, pending prospective validation in cohorts with Doppler-based FGR ascertainment.