Zonulin is a novel
biomarker of intestinal permeability. The existing data suggest that upregulation of
zonulin might be linked to systemic
inflammation and
pregnancy complications. A systematic search was performed in medical electronic databases to identify eligible studies that reported circulating
zonulin levels in complicated pregnancies compared to controls. Eight studies with 1196 serum samples of pregnant women were included in the systematic review. Meta-analysis on four studies revealed a significant increase in serum
zonulin in women with
Gestational diabetes mellitus (GDM) compared to healthy controls (Cohen's d = 2.06; 95% Confidence Interval (CI): 0.15, 3.98). By pooling four studies that investigated
zonulin levels in Hypertensive disorders of pregnancy (HDP), higher
zonulin concentrations were found in cases, while the difference was not significant (Cohen's d = 0.86; 95% CI: -0.04, 1.75). Current evidence suggests that higher levels of
zonulin during pregnancy seem to be associated with
inflammation-related complications, including GDM and HDP.Impact StatementWhat is already known on this subject? Increased
zonulin levels are considered as a marker of intestinal hyper-permeability. Upregulation of
zonulin and concurrent systemic
inflammation, are known to be associated with some
pregnancy complications.What do the results of this study add? We performed a meta-analysis to evaluate changes in serum
zonulin levels in pregnancies complicated with
Gestational diabetes mellitus (GDM), Hypertensive disorders of pregnancy (HDP), and
Intrahepatic cholestasis of pregnancy (ICP). According to our results,
zonulin levels were significantly higher in complicated pregnancies than in normal pregnancies, particularly for GDM.What are the implications of these findings for clinical practice and/or further research? Our findings revealed a probable association between increased
zonulin levels and
inflammation-related complications during pregnancy. Moreover,
zonulin could serve as a reliable diagnostic clinical
biomarker to identify (or predict) complications during pregnancy. Further studies are needed to examine the clinical accuracy of
zonulin for detecting pregnancy-related complications.