Carcinoembryonic antigen as a biomarker for meconium-stained amniotic fluid

Objective: To assess whether elevated carcinoembryonic antigen (CEA) concentration in amniotic fluid can indicate meconium-stained amniotic fluid (MSAF). Methods: In a prospective cohort study, women with a term singleton pregnancy who were in labor but had intact membranes were recruited at a center in Israel over a 5-month period in 2013. Only women who subsequently underwent artificial rupture of membranes following a clear medical indication were included. Samples of amniotic fluid, urine, and serum were collected. Amniotic fluid was examined by sight and classified as clear, MSAF, or undetermined. CEA concentration in the samples was measured. Results: Among 81 participants, 45 had clear amniotic fluid, 28 had MSAF, and eight had undetermined amniotic fluid. Mean CEA concentration was more than 10 times higher in MSAF (2658 mu g/L, standard error 250) than in clear amniotic fluid (238 mu g/L, standard error 29; P < 0.001). Receiver operating characteristic curve analysis demonstrated a sensitivity of 96% and a specificity of 100% for distinguishing MSAF from clear amniotic fluid at a CEA cutoff of 799.2 mu g/L. CEA concentrations in urine and serum were all within the normal range (<= 5 mu g/L), irrespective of amniotic fluid status. Conclusion: High CEA concentrations in amniotic fluid can assist in the diagnosis of MSAF. These findings could provide the basis for a bedside test to detect MSAF following rupture of membranes. (C) 2015 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.