Objective: To determine if alpha-fetoprotein (AFP) concentration in vaginal blood, in the setting of dissolved fetal tissue, is significantly higher than its concentration in the maternal serum.
Design: A prospective cohort study.
Setting: Medical center.
Patient(s): Four groups of women were evaluated: 1) with missed/incomplete miscarriage with vaginal bleeding; 2) with threatened miscarriage; 3) with vaginal bleeding during cerclage placement; and 4) undergoing dilation and curettage (D&C).
Interventions(s): None.
Main outcome measure(s): In each patient, AFP concentration in the vaginal blood or in the liquid component of the evacuated products of conception (POC; D&C group) was compared with the AFP concentration in the maternal serum.
Result(s): The median (range) concentration ratios of AFP in vaginal blood (or POC) to AFP in maternal serum were 24.5 (5.1-8,620) and 957 (4.6-24,216) for the missed/incomplete (n = 30) and the D&C (n = 22) groups, respectively, whereas they were only 1.2 (0.4-13.4) and 1.01 (0.7-1.5) for the threatened miscarriage (n = 15) and cerclage (n = 9) groups, respectively. Receiver operating characteristic (ROC) analysis demonstrated 100% sensitivity and 86.7% specificity for the detection of the passage of fetal tissue (ratio 4.3, area under the ROC curve 0.96).
Conclusion(s): Higher concentrations of AFP in vaginal blood than in maternal serum may indicate the presence of dissolved fetal tissue (i.e., confirming a failed pregnancy).
Keywords: Alpha-fetoprotein; miscarriage; rapid test.
Copyright © 2018 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.