A Comparative Evaluation of Sonographic Markers, Progesterone, and Hematological Indices in First-Trimester Missed Abortion

Introduction: Despite advancements in early pregnancy monitoring, accurately identifying asymptomatic fetal loss remains a significant clinical challenge.In light of conflicting evidence in the literature, this prospective study was designed to conduct a multimodal comparative evaluation of sonographic markers [gestational sac (GS), yolk sac (YS), crown-rump length (CRL)], serum progesterone, and a comprehensive panel of systemic inflammatory indices [neutrophil-to-lymphocyte ratio (NLR), lymphocyteto-monocyte ratio (LMR), mean platelet volume (MPV), platelet distribution width] in the context of first-trimester missed abortion.Methods: A total of 129 pregnant women (51 with missed abortion and 78 healthy controls) at 6-9 gestational weeks were prospectively enrolled.Serum progesterone and complete blood count parameters were analyzed at the time of diagnosis.Diagnostic performance was evaluated using receiver operating characteristic (ROC) analysis, and independent associations were evaluated using multivariable logistic regression.Results: In the missed abortion group, GS and CRL measurements were significantly smaller (p<0.001),whereas YS diameter was significantly larger than in healthy pregnancies (p=0.039).Serum progesterone levels were markedly lower in cases (10.4±5.2 ng/ mL vs. 17.1±5.1 ng/ mL, p<0.001).Multivariable analysis identified lower serum progesterone [odds ratio (OR): 0.791], smaller GS diameter (OR: 0.839, p=0.004), and larger YS diameter (OR: 2.255, p=0.044) as strong independent indicators of missed abortion.ROC analysis confirmed that serum progesterone had the highest discriminatory power [area under the curve (AUC): 0.840, p<0.001)], followed by CRL (AUC: 0.754), and GS diameter (AUC: 0.738).While absolute lymphocyte counts were significant in univariate models (p=0.012),systemic inflammatory markers (NLR, LMR, MPV) failed to show independent diagnostic performance.Conclusion: Morphometric sonographic parameters and serum progesterone levels are independently associated with first-trimester missed abortion, reinforcing their reliability as clinical indicators for identifying non-viable pregnancies.Conversely, routine systemic inflammatory markers lack a sufficient independent association to serve as useful standalone markers for asymptomatic fetal loss.Clinical assessment should prioritize standardized sonographic and hormonal profiles over hematological indices.