Background/Objectives: To investigate maternal serum Isthmin-1 (ISM1) levels in pregnancies complicated by fetal growth restriction (FGR) and to evaluate its potential discriminatory performance for FGR. Methods: This prospective cross-sectional study included 44 pregnant women with late-onset FGR and 43 gestational age-matched healthy controls. FGR was diagnosed according to one of two criteria: (1) estimated fetal weight (EFW) below the 3rd percentile, or (2) EFW between the 3rd and 10th percentile with at least one abnormal Doppler finding (Umbilical Artery Pulsatility Index (UA-PI), Middle Cerebral Artery Pulsatility Index (MCA-PI), or Cerebroplacental Ratio (CPR). Maternal serum ISM1 concentrations were measured using enzyme-linked immunosorbent assay (ELISA). Ultrasonographic parameters, Doppler indices, and perinatal outcomes were compared between groups. Correlation and receiver operating characteristic (ROC) analyses were performed to assess diagnostic performance. Results: Maternal ISM1 levels were significantly lower in the FGR group compared with controls [10.63 (9.95–12.10) vs. 12.40 (10.75–13.25) ng/mL, p = 0.003]. ISM1 correlated negatively with FGR presence (r = −0.318, p = 0.003) and positively with EFW percentile (r = 0.235, p = 0.028). ROC analysis showed moderate diagnostic accuracy Area Under the Curve (AUC) = 0.684, 95% CI: 0.575–0.779) with 70.5% sensitivity and 72.1% specificity at a cut-off ≤11.5 ng/mL. No significant association was found between ISM1 and composite adverse perinatal outcomes. Conclusions: Levels of ISM1 in maternal serum were found to be significantly lower in pregnancies complicated by FGR, supporting a potential association between ISM1 and impaired fetal growth. However, its moderate diagnostic performance and lack of association with adverse perinatal outcomes indicate that ISM1 should currently be regarded as a promising exploratory biomarker rather than a standalone diagnostic or prognostic marker. Further studies are needed to validate these findings and to determine whether ISM1 provides additional value when combined with established Doppler and angiogenic markers.

Aim: Placenta accreta spectrum (PAS) is a severe obstetric condition characterized by abnormal trophoblast invasion and increased maternal morbidity. Laeverin (LVN), a trophoblast-specific peptidase involved in cell invasion, has been implicated in placental pathophysiology. This study aimed to evaluate maternal serum LVN levels in pregnancies complicated by PAS and to assess its diagnostic and discriminative utility. Materials and Methods: This prospective case–control study included 88 pregnant women (44 with PAS and 44 gestational age and BMI matched controls) managed at a tertiary center between July 2025 and March 2026. PAS diagnosis was established by ultrasonography and confirmed intraoperatively and histopathologically. Maternal serum LVN levels were measured using ELISA. Receiver operating characteristic (ROC) analysis and regression analyses were performed. Results: Maternal serum LVN levels did not differ between PAS and control groups (0.07 vs. 0.06 ng/mL, p = 0.401) and were not associated with PAS severity or clinical outcomes. ROC analysis showed poor discriminative ability (AUC = 0.552, p = 0.404). In contrast, maternal age (aOR: 1.106, 95% CI: 1.004–1.219, p = 0.042) and previous cesarean section history (aOR: 3.757, 95% CI: 1.800–7.841, p < 0.001) were independent predictors of PAS. Conclusion: Maternal serum LVN levels did not differ between PAS and healthy pregnancies and did not demonstrate meaningful diagnostic or diagnostic utility in this cohort. These findings highlight the limited utility of circulating biomarkers and emphasize the importance of established clinical risk factors in PAS diagnostic utility.

Objective: To evaluate the clinical significance of a flat oral glucose tolerance test (OGTT) pattern and its association with obstetric and perinatal outcomes, focusing on fetal growth. Methods: This retrospective cohort study was conducted at a tertiary referral center between January 2023 and November 2025. A total of 1198 women who underwent a two-step OGTT between 24 and 32 weeks of gestation were screened, and 685 eligible participants were included. A flat OGTT pattern was defined as fasting glucose < 95 mg/dL with all postprandial values < 100 mg/dL. The primary outcome was small-for-gestational-age (SGA); secondary outcomes included fetal growth restriction (FGR) and other obstetric outcomes. Logistic regression analyses were performed to assess independent associations. Results: Thirty-nine women (5.7%) exhibited a flat OGTT pattern. These pregnancies were characterized by a markedly attenuated postprandial glycemic response and lower fasting glucose levels. Most maternal and neonatal outcomes were similar between groups. However, SGA was significantly more frequent in the flat OGTT group (20.5% vs. 6.7%, p = 0.001). In multivariable analysis, a flat OGTT pattern remained independently associated with SGA (aOR 4.05, 95% CI 1.70–9.68, p = 0.002). Both SGA and FGR were more frequent among women with a flat OGTT pattern, although the association appeared stronger for SGA. Conclusions: A flat OGTT pattern appears to represent a distinct glycemic response characterized by an attenuated postprandial glucose response and lower fasting glucose levels. Although this pattern was not associated with a generalized increase in adverse obstetric or neonatal outcomes, it was associated with an increased risk of small-for-gestational-age infants.

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.