Maternal serum endocan level may be a useful marker for predicting preterm birth (PTB) within 7 days in patients with threatened preterm labor, according to a cross-sectional prospective study in The Journal of Maternal-Fetal & Neonatal Medicine. Endocan is a soluble proteoglycan secreted by the vascular endothelium.
The Turkish authors sought to ascertain serum endocan levels in patients with threatened preterm labor and to determine whether endocan levels in patients with true preterm labor who give birth within 7 days differ from endocan levels in patients with false preterm labor and uncomplicated pregnancy.
The study consisted of 58 patients diagnosed with threatened preterm labor and 31 healthy pregnant women (control group) matched for gestational age. Patients with threatened preterm labor were divided into two groups: PTB (n = 28) and term delivery (n = 30). Maternal serum endocan levels were measured via an enzyme-linked immunosorbent assay kit.
Median serum endocan level (pg/mL) in patients with threatened preterm labor was significantly higher than in those with uncomplicated pregnancies (the control group): 725 (interquartile range [IQR] 619 to 823) vs. 310 (IQR 218 to 423), respectively (P < 0.001). Median serum endocan level in the preterm delivery group was also higher than in the term delivery and control groups: 823 (IQR 718 to 905) vs. 637 (IQR 590 to 729) vs. 310 (IQR 218 to 423, respectively (P < 0.001).
The threshold value of maternal serum endocan level for predicting delivery within 7 days after admission was calculated at 655 pg/mL, whereas the area under the curve (AUC) was 0.934 (95% confidence interval [CI]: 0.88 to 0.98) (P < .001), along with 85.7% sensitivity and 78.7% specificity.
Mean cervical length was also significantly higher in the control group: 37.9 mm compared to 24.7 mm in the term delivery group and 22.6 mm in the PTB group (P < .001). Because all symptomatic women had a similar cervical length, “serum endocan concentration provides additional information to the cervical length measurement in short-term prediction of preterm delivery,” the authors wrote.
On the other hand, maternal characteristics including age, body mass index (BMI), gravidity, gestational age at blood sampling, and C-reactive protein (CRP) and hemoglobin (Hb) levels, were not dramatically different between the three groups (P > 0.05). The authors said endocan might play an important role in the vascular contribution to organ-specific inflammation, as well as being a novel endothelial cell dysfunction marker.
Previous studies have shown that serum endocan concentration is higher in some patients with sepsis and at the onset of infection compared to healthy individuals. “We speculate that increased maternal serum endocan levels may be related to the inflammatory process which is the predominant feature of preterm delivery,” the current study authors wrote.
Successfully identifying women at high risk for PTB will facilitate treatment, according to the authors, such as targeted use of steroids or in utero transfer. Due to the relatively small sample size of the study groups, however, additional studies with larger sample sizes and complicated pregnancies are needed to validate the results.