Objective: Our objectives were to evaluate maternal serum YKL-40 levels in pregnancies complicated by preterm prelabor rupture of membranes (PPROM), compare them with healthy gestational age-comparable controls, and assess the association between YKL-40 levels and subsequent composite adverse neonatal outcomes (CANOs). Methods: This prospective observational study included 44 women with PPROM and 44 healthy pregnant controls between 24 and 37 weeks of gestation. Maternal serum YKL-40 concentrations were measured using an enzyme-linked immunosorbent assay (ELISA), with concentrations corrected for the manufacturer-specified 5-fold sample dilution. Multivariable Firth’s penalized logistic regression was used to evaluate the independent association of YKL-40 with PPROM and, within the PPROM cohort only, subsequent CANO. Exploratory receiver operating characteristic (ROC) analysis was performed to assess the ability of YKL-40 to discriminate established PPROM cases from healthy controls. The study was powered a priori only for the primary between-group comparison of YKL-40; the ROC and CANO analyses were not separately powered and are reported as exploratory. Results: Maternal serum YKL-40 levels were significantly higher in the PPROM group than in the control group (5.87 ± 2.64 vs. 2.44 ± 0.96 ng/mL, p < 0.001). In multivariable analysis, YKL-40 remained independently associated with PPROM (adjusted odds ratio 5.61, 95% CI 2.07–15.23, p < 0.001 per 1 ng/mL increase). Within the PPROM cohort, YKL-40 was not independently associated with CANO (p = 0.775). Exploratory ROC analysis yielded an AUC of 0.935 (95% CI 0.881–0.989); a ROC-derived cut-off of >3.3 ng/mL provided 86.4% sensitivity and 84.1% specificity for discriminating established PPROM cases from healthy controls. Conclusions: Maternal serum YKL-40 levels were significantly elevated in women with established PPROM and remained independently associated with PPROM status, but were not associated with subsequent CANO. Because YKL-40 was measured after PPROM diagnosis, the observed ROC performance reflects case–control discrimination rather than prospective prediction or established diagnostic utility. Larger prospective studies using clinically relevant comparison groups and independently validated assays are required to determine the potential clinical value of YKL-40 in PPROM.

Aims: To evaluate prenatal imaging findings, associated structural abnormalities, genetic testing results, and neonatal outcomes in fetuses with corpus callosum anomalies, and to compare corpus callosum dysplasia with agenesis.Methods: This retrospective cross-sectional study included 42 pregnancies complicated by fetal corpus callosum anomalies: 24 cases of corpus callosum dysplasia and 18 cases of corpus callosum agenesis. Prenatal ultrasonographic findings, fetal magnetic resonance imaging (MRI) findings, invasive prenatal genetic testing results, associated structural abnormalities, and neonatal outcomes were evaluated retrospectively.Results: Associated structural abnormalities on prenatal ultrasonography were observed in 83.3% of the dysplasia group and in all fetuses in the agenesis group (p=0.122). Ventriculomegaly-related abnormalities were the most common associated findings in both groups. Colpocephaly, interhemispheric cysts, facial anomalies, and multisystem structural abnormalities were more prominent in the agenesis group. Fetal MRI findings mainly included cavum septi pellucidi abnormalities, ventriculomegaly, and colpocephaly. Prenatal genetic evaluation identified abnormalities involving genes such as L1CAM, FGFR1, and KIF7. The agenesis group had lower birth weights and higher neonatal intensive care unit admission rates compared with the dysplasia group.Conclusion: Fetuses with corpus callosum agenesis showed a tendency toward a more severe phenotypic spectrum, with more associated structural abnormalities and less favorable neonatal characteristics compared with fetuses with corpus callosum dysplasia. Comprehensive prenatal evaluation that integrates neurosonography, fetal MRI, and genetic testing is essential for accurate characterization and prognostic counseling in fetal corpus callosum anomalies.