Thickness of fetal membranes: a possible ultrasound marker for preterm delivery

Authors

  • F. M. Severi,

    1. Division of Obstetrics and Gynecology, Department of Pediatrics, Obstetrics and Reproductive Medicine, University of Siena, Siena, Italy
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  • C. Bocchi,

    1. Division of Obstetrics and Gynecology, Department of Pediatrics, Obstetrics and Reproductive Medicine, University of Siena, Siena, Italy
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  • C. Voltolini,

    1. Division of Obstetrics and Gynecology, Department of Pediatrics, Obstetrics and Reproductive Medicine, University of Siena, Siena, Italy
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  • L. E. Borges,

    1. Division of Obstetrics and Gynecology, Department of Pediatrics, Obstetrics and Reproductive Medicine, University of Siena, Siena, Italy
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  • P. Florio,

    1. Division of Obstetrics and Gynecology, Department of Pediatrics, Obstetrics and Reproductive Medicine, University of Siena, Siena, Italy
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  • F. Petraglia

    Corresponding author
    1. Division of Obstetrics and Gynecology, Department of Pediatrics, Obstetrics and Reproductive Medicine, University of Siena, Siena, Italy
    • Division of Obstetrics and Gynecology, University of Siena, Policlinico ‘Santa Maria alle Scotte’, Viale Bracci, 53100 Siena, Italy
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Abstract

Objective

To evaluate whether measurement of the thickness of the fetal membranes by high-resolution ultrasound is a useful marker to predict preterm delivery.

Methods

One hundred and fifty-eight women with singleton pregnancies at 18–35 gestational weeks were enrolled consecutively at our referral center for obstetric care and the thickness of their fetal membranes was measured using high-resolution ultrasound equipment. Data were analyzed to determine whether there were significant differences between those delivering at term and those delivering preterm. Receiver–operating characteristics (ROC) curves were used to determine the best cut-off point of membrane thickness for predicting preterm birth.

Results

Women who delivered preterm had greater fetal membrane thickness than did those who delivered at term (1.67 ± 0.27 mm vs. 1.14 ± 0.30 mm, P < 0.0001). For the best cut-off indicated by ROC curve analysis (1.2 mm), the sensitivity and specificity for predicting preterm birth were 100% (95% CI, 80.3–100) and 69.5% (95% CI, 61.2–77.0), respectively, and positive and negative likelihood ratios were 3.3 and 0.0, respectively.

Conclusion

Sonographic measurement of fetal membrane thickness could be helpful in the prediction of preterm delivery. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.

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