Assessment of amniotic fluid volume
- Everett Magann, MD
Everett Magann, MD
- Professor of Obstetrics and Gynecology, Division Director
- Department of Obstetrics and Gynecology
- University of Arkansas for the Medical Sciences (UAMS)
- Michael G Ross, MD, MPH
Michael G Ross, MD, MPH
- Distinguished Professor of Obstetrics and Gynecology
- David Geffen School of Medicine at UCLA
- Section Editors
- Deborah Levine, MD
Deborah Levine, MD
- Section Editor — Imaging
- Professor of Radiology
- Director of Ob/Gyn Ultrasound
- Department of Radiology
- Beth Israel Deaconess Medical Center
- Lynn L Simpson, MD
Lynn L Simpson, MD
- Section Editor — Obstetrics
- Professor of Obstetrics and Gynecology
- Columbia University College of Physicians and Surgeons
Normal amniotic fluid volume (AFV) varies across gestation (figure 1). The sonographic assessment of AFV will be discussed here. Factors that influence AFV and specific disorders of AFV (oligohydramnios and polyhydramnios) are reviewed separately:
WHEN TO ASSESS AFV
Qualitative or semi-quantitative assessment of AFV is a standard component of every second- and third-trimester ultrasound examination [1,2].
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- Locatelli A, Zagarella A, Toso L, et al. Serial assessment of amniotic fluid index in uncomplicated term pregnancies: prognostic value of amniotic fluid reduction. J Matern Fetal Neonatal Med 2004; 15:233.
- Chauhan SP, Sanderson M, Hendrix NW, et al. Perinatal outcome and amniotic fluid index in the antepartum and intrapartum periods: A meta-analysis. Am J Obstet Gynecol 1999; 181:1473.
- Dildy GA 3rd, Lira N, Moise KJ Jr, et al. Amniotic fluid volume assessment: comparison of ultrasonographic estimates versus direct measurements with a dye-dilution technique in human pregnancy. Am J Obstet Gynecol 1992; 167:986.
- Magann EF, Whitworth NS, Files JC, et al. Dye-dilution techniques using aminohippurate sodium: do they accurately reflect amniotic fluid volume? J Matern Fetal Neonatal Med 2002; 11:167.
- Magann EF, Perry KG Jr, Chauhan SP, et al. The accuracy of ultrasound evaluation of amniotic fluid volume in singleton pregnancies: the effect of operator experience and ultrasound interpretative technique. J Clin Ultrasound 1997; 25:249.
- Magann EF, Chauhan SP, Washington W, et al. Ultrasound estimation of amniotic fluid volume using the largest vertical pocket containing umbilical cord: measure to or through the cord? Ultrasound Obstet Gynecol 2002; 20:464.
- Reddy UM, Abuhamad AZ, Levine D, et al. Fetal imaging: executive summary of a joint Eunice Kennedy Shriver National Institute of Child Health and Human Development, Society for Maternal-Fetal Medicine, American Institute of Ultrasound in Medicine, American College of Obstetricians and Gynecologists, American College of Radiology, Society for Pediatric Radiology, and Society of Radiologists in Ultrasound Fetal Imaging workshop. Obstet Gynecol 2014; 123:1070.
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- Magann EF, Nolan TE, Hess LW, et al. Measurement of amniotic fluid volume: accuracy of ultrasonography techniques. Am J Obstet Gynecol 1992; 167:1533.
- Horsager R, Nathan L, Leveno KJ. Correlation of measured amniotic fluid volume and sonographic predictions of oligohydramnios. Obstet Gynecol 1994; 83:955.
- Rutherford SE, Phelan JP, Smith CV, Jacobs N. The four-quadrant assessment of amniotic fluid volume: an adjunct to antepartum fetal heart rate testing. Obstet Gynecol 1987; 70:353.
- ACOG Committee on Practice Bulletins-Obstetrics. ACOG Practice Bulletin. Clinical management guidelines for obstetricians-gynecologists. Number 55, September 2004 (replaces practice pattern number 6, October 1997). Management of Postterm Pregnancy. Obstet Gynecol 2004; 104:639.
- Phelan JP, Ahn MO, Smith CV, et al. Amniotic fluid index measurements during pregnancy. J Reprod Med 1987; 32:601.
- Magann EF, Chauhan SP, Hitt WC, et al. Borderline or marginal amniotic fluid index and peripartum outcomes: a review of the literature. J Ultrasound Med 2011; 30:523.
- Magann EF, Morton ML, Nolan TE, et al. Comparative efficacy of two sonographic measurements for the detection of aberrations in the amniotic fluid volume and the effect of amniotic fluid volume on pregnancy outcome. Obstet Gynecol 1994; 83:959.
- Chauhan SP, Magann EF, Morrison JC, et al. Ultrasonographic assessment of amniotic fluid does not reflect actual amniotic fluid volume. Am J Obstet Gynecol 1997; 177:291.
- Magann EF, Doherty DA, Chauhan SP, et al. How well do the amniotic fluid index and single deepest pocket indices (below the 3rd and 5th and above the 95th and 97th percentiles) predict oligohydramnios and hydramnios? Am J Obstet Gynecol 2004; 190:164.
- Magann EF, Isler CM, Chauhan SP, Martin JN Jr. Amniotic fluid volume estimation and the biophysical profile: a confusion of criteria. Obstet Gynecol 2000; 96:640.
- Magann EF, Nevils BG, Chauhan SP, et al. Low amniotic fluid volume is poorly identified in singleton and twin pregnancies using the 2 x 2 cm pocket technique of the biophysical profile. South Med J 1999; 92:802.
- Bianco A, Rosen T, Kuczynski E, et al. Measurement of the amniotic fluid index with and without color Doppler. J Perinat Med 1999; 27:245.
- Goldkrand JW, Hough TM, Lentz SU, et al. Comparison of the amniotic fluid index with gray-scale and color Doppler ultrasound. J Matern Fetal Neonatal Med 2003; 13:318.
- Magann EF, Chauhan SP, Barrilleaux PS, et al. Ultrasound estimate of amniotic fluid volume: color Doppler overdiagnosis of oligohydramnios. Obstet Gynecol 2001; 98:71.
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- Magann EF, Doherty DA, Field K, et al. Biophysical profile with amniotic fluid volume assessments. Obstet Gynecol 2004; 104:5.
- Nabhan AF, Abdelmoula YA. Amniotic fluid index versus single deepest vertical pocket as a screening test for preventing adverse pregnancy outcome. Cochrane Database Syst Rev 2008; :CD006593.
- Kehl S, Schelkle A, Thomas A, et al. Single deepest vertical pocket or amniotic fluid index as evaluation test for predicting adverse pregnancy outcome (SAFE trial): a multicenter, open-label, randomized controlled trial. Ultrasound Obstet Gynecol 2016; 47:674.
- Moore TR, Cayle JE. The amniotic fluid index in normal human pregnancy. Am J Obstet Gynecol 1990; 162:1168.
- Magann EF, Sanderson M, Martin JN, Chauhan S. The amniotic fluid index, single deepest pocket, and two-diameter pocket in normal human pregnancy. Am J Obstet Gynecol 2000; 182:1581.
- Magann EF, Chauhan SP, Whitworth NS, et al. Subjective versus objective evaluation of amniotic fluid volume of pregnancies of less than 24 weeks' gestation: how can we be accurate? J Ultrasound Med 2001; 20:191.
- Magann EF, Whitworth NS, Bass JD, et al. Amniotic fluid volume of third-trimester diamniotic twin pregnancies. Obstet Gynecol 1995; 85:957.
- Ippolito DL, Bergstrom JE, Lutgendorf MA, et al. A systematic review of amniotic fluid assessments in twin pregnancies. J Ultrasound Med 2014; 33:1353.
- Magann EF, Chauhan SP, Whitworth NS, et al. Determination of amniotic fluid volume in twin pregnancies: ultrasonographic evaluation versus operator estimation. Am J Obstet Gynecol 2000; 182:1606.
- Magann EF, Doherty DA, Ennen CS, et al. The ultrasound estimation of amniotic fluid volume in diamniotic twin pregnancies and prediction of peripartum outcomes. Am J Obstet Gynecol 2007; 196:570.e1.
- Chau AC, Kjos SL, Kovacs BW. Ultrasonographic measurement of amniotic fluid volume in normal diamniotic twin pregnancies. Am J Obstet Gynecol 1996; 174:1003.
- Porter TF, Dildy GA, Blanchard JR, et al. Normal values for amniotic fluid index during uncomplicated twin pregnancy. Obstet Gynecol 1996; 87:699.
- Hill LM, Krohn M, Lazebnik N, et al. The amniotic fluid index in normal twin pregnancies. Am J Obstet Gynecol 2000; 182:950.
- Magann EF, Chauhan SP, Whitworth NS, et al. The accuracy of the summated amniotic fluid index in evaluating amniotic fluid volume in twin pregnancies. Am J Obstet Gynecol 1997; 177:1041.
- WHEN TO ASSESS AFV
- CLINICAL SIGNIFICANCE OF ABNORMAL AFV
- DYE DILUTION AND COLLECTION OF AMNIOTIC FLUID: THE REFERENCE STANDARDS
- ULTRASOUND ESTIMATION OF AFV
- Qualitative assessment
- Semi-quantitative methods
- - Single deepest pocket
- - Amniotic fluid index
- - Two-diameter pocket technique
- - 2 by 1 cm or 2 by 2 cm pocket technique
- Use of concurrent color Doppler
- Our approach
- SPECIAL POPULATIONS
- Gestational age 14 to 20 weeks
- Multifetal pregnancy
- SUMMARY AND RECOMMENDATIONS