Trimester-Specific Diagnostic Accuracy of Amniotic Fluid α-Fetoprotein for Detecting Preterm Premature Rupture of Membranes Versus AmniSure
5 affiliations
- 1Iranian Society of Perinatology, Maternal-Fetal Medicine Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
- 2Maternal-Fetal Medicine Research Center, Department of Obstetrics and Gynecology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
- 3Anesthesiology and Critical Care Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
- 4Infertility Research Center, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
- 5Maternal-Fetal Medicine Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
Abstract
Background: Preterm premature rupture of membranes (PPROM) is a critical obstetric complication that accounts for 3-10% of pregnancies and a substantial proportion of preterm births, with considerable maternal and neonatal morbidity. Early and precise diagnosis remains challenging because of limitations in current clinical tests, increasing the need for reliable biochemical markers.
Materials and Methods: In this cross-sectional study, 177 pregnant women with clinical suspicion of PPROM before 37 weeks of gestation were enrolled and classified by trimester. Amniotic fluid alpha-fetoprotein (AFP), AmniSure, and Fern tests were performed on vaginal fluid samples. Sensitivity, specificity, and receiver operating characteristic (ROC) curve analyses were used to determine diagnostic performance, and optimal AFP thresholds were established for each trimester.
Results: AFP distinguished PPROM from non-PPROM cases in all trimesters, with area under the ROC curve values exceeding 0.92 and reaching 0.97 in the third trimester. Trimester-specific AFP cutoffs maximized sensitivity (80.5-97.1%) and specificity (83.3–100%). The Fern test showed lower sensitivity and more discrepancies, particularly in early gestation, while the overall agreement between AmniSure and Fern testing was strong (κ=0.85).
Conclusion: Vaginal fluid AFP measurement may be a practical and accurate diagnostic adjunct for PPROM across gestational ages, particularly when trimester-specific cutoffs are applied. AFP testing may be useful where access to proprietary assays is limited, but external validation is required before routine replacement of established diagnostic methods.
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BibTeX
@article{vafaei2026trimesterspecific,
title = {{Trimester-Specific Diagnostic Accuracy of Amniotic Fluid α-Fetoprotein for Detecting Preterm Premature Rupture of Membranes Versus AmniSure}},
author = {Homeira Vafaei and Vida Amiri and Naeimehossadat Asmarian and Behrouz Gharesi-Fard and Shaghayegh Moradi Alamdarloo and Nasrin Asadi and Azam Faraji and Shohreh Roozmeh and Khadije Bazrafshan},
journal = {Galen Medical Journal},
year = {2026},
month = oct,
doi = {10.31661/gmj.v15i.3627},
url = {https://doi.org/10.31661/gmj.v15i.3627},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Trimester-Specific Diagnostic Accuracy of Amniotic Fluid α-Fetoprotein for Detecting Preterm Premature Rupture of Membranes Versus AmniSure
AU - Homeira Vafaei
AU - Vida Amiri
AU - Naeimehossadat Asmarian
AU - Behrouz Gharesi-Fard
AU - Shaghayegh Moradi Alamdarloo
AU - Nasrin Asadi
AU - Azam Faraji
AU - Shohreh Roozmeh
AU - Khadije Bazrafshan
PY - 2026
DA - 2026/10/04
JO - Galen Medical Journal
DO - 10.31661/gmj.v15i.3627
UR - https://doi.org/10.31661/gmj.v15i.3627
AB - Background: Preterm premature rupture of membranes (PPROM) is a critical obstetric complication that accounts for 3-10% of pregnancies and a substantial proportion of preterm births, with considerable maternal and neonatal morbidity. Early and precise diagnosis remains challenging because of limitations in current clinical tests, increasing the need for reliable biochemical markers. Materials and Methods: In this cross-sectional study, 177 pregnant women with clinical suspicion of PPROM before 37 weeks of gestation were enrolled and classified by trimester. Amniotic fluid alpha-fetoprotein (AFP), AmniSure, and Fern tests were performed on vaginal fluid samples. Sensitivity, specificity, and receiver operating characteristic (ROC) curve analyses were used to determine diagnostic performance, and optimal AFP thresholds were established for each trimester. Results: AFP distinguished PPROM from non-PPROM cases in all trimesters, with area under the ROC curve values exceeding 0.92 and reaching 0.97 in the third trimester. Trimester-specific AFP cutoffs maximized sensitivity (80.5-97.1%) and specificity (83.3–100%). The Fern test showed lower sensitivity and more discrepancies, particularly in early gestation, while the overall agreement between AmniSure and Fern testing was strong (κ=0.85). Conclusion: Vaginal fluid AFP measurement may be a practical and accurate diagnostic adjunct for PPROM across gestational ages, particularly when trimester-specific cutoffs are applied. AFP testing may be useful where access to proprietary assays is limited, but external validation is required before routine replacement of established diagnostic methods.
SN - 2588-2767
SN - 2322-2379
ER -