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Magann EF, Whittington JR, Morrison JC, Chauhan SP. Amniotic Fluid Volume Assessment: Eight Lessons Learned. Int J Womens Health 2021; 13:773-779. [PMID: 34429662 PMCID: PMC8375311 DOI: 10.2147/ijwh.s316841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Accepted: 08/03/2021] [Indexed: 11/23/2022] Open
Abstract
Actual AFV can be determined by a dye-dilution technique or be directly measured at cesarean. This allows investigators to correlate estimated and actual AFVs. Lessons learned by assessing the relationship of estimated to actual AFVs. 1) Ultrasound estimates normal actual AFVs well, but abnormal AFVs poorly. 2) Quantile regression is a better statistical methodology to create a normal AFV curve across pregnancy. 3) There is no difference in the accuracy of the subjective (visualization without measurements) compared with the objective (visualization with measurements) technique in identifying normal and abnormal AFVs. 4) Color Doppler use leads to the over-diagnosis of oligohydramnios. 5) Intravenous hydration increases actual AFVs. 6) The estimation of AFV can be done with the transducer held perpendicular to the floor or perpendicular to the uterine contour. 7) The single deepest pocket should be used for identifying low AFVs. 8) The AFI should be used for identifying high AFVs.
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Affiliation(s)
- Everett F Magann
- Departments of Obstetrics and Gynecology of the University of Arkansas for the Medical Sciences, Little Rock, AR, USA
| | - Julie R Whittington
- Departments of Obstetrics and Gynecology of the University of Arkansas for the Medical Sciences, Little Rock, AR, USA
| | - John C Morrison
- Department of Obstetrics and Gynecology of the University of Mississippi Medical Center, Jackson, MS, USA
| | - Suneet P Chauhan
- Department of Obstetrics, Gynecology and Reproductive Sciences of the University of Texas Health Sciences Center at Houston, Houston, TX, USA
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Hughes DS, Magann EF. Antenatal fetal surveillance "Assessment of the AFV". Best Pract Res Clin Obstet Gynaecol 2016; 38:12-23. [PMID: 27756534 DOI: 10.1016/j.bpobgyn.2016.08.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 06/10/2016] [Accepted: 08/08/2016] [Indexed: 11/29/2022]
Abstract
The evaluation of amniotic fluid volume (AFV) is an established part of the antenatal surveillance of pregnancies at risk for an adverse pregnancy outcome. The two most commonly used ultrasound techniques to estimate AFV are the amniotic fluid index (AFI) and the single deepest pocket (SDP). Four studies have defined normal AFVs, and although their normal volumes have similarities, there are also differences primarily due to the statistical methodology used in each study. Dye-determined AFV correlates with ultrasound estimates for normal fluid volumes but correlates poorly for oligohydramnios and polyhydramnios. The addition of color Doppler in estimating AFV leads to the overdiagnosis of oligohydramnios. Neither the AFI nor the SDP is superior in identifying oligohydramnios, but the SDP is a better measurement choice as the use of AFI increases the diagnosis rate of oligohydramnios and labor inductions without an improvement in pregnancy outcomes.
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Affiliation(s)
- Dawn S Hughes
- Department of Obstetrics and Gynecology, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Everett F Magann
- Department of Obstetrics and Gynecology, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
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Aminotic Fluid Index and its Correlation with Fetal Growth and Perinatal Outcome. JOURNAL OF FETAL MEDICINE 2015. [DOI: 10.1007/s40556-015-0049-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Ippolito DL, Bergstrom JE, Lutgendorf MA, Flood-Nichols SK, Magann EF. A systematic review of amniotic fluid assessments in twin pregnancies. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2014; 33:1353-1364. [PMID: 25063400 DOI: 10.7863/ultra.33.8.1353] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The objectives of this systematic review were to examine the reproducibility of sonographic estimates of amniotic fluid volume (AFV) in twin pregnancies, compare the association of sonographic estimates of AFV with dye-determined AFV, and correlate AFV with antepartum, intrapartum, and perinatal outcomes in twin pregnancies. Studies were included if they were adequately powered and investigated antepartum, intrapartum, and/or perinatal adverse outcome parameters in twin gestations. Studies with comparable populations and exclusion criteria were merged into forest plots. Data comparing the accuracy of AFV assessment, correlation of AFV with gestational age, and adverse outcomes were tabulated. Five of the 6 studies investigating AFV by the amniotic fluid index as a function of gestational age reported data fitting a quadratic equation, with fluid volumes peaking at mid gestation and then declining. This trend was less pronounced when AFV was assessed by the single deepest pocket (2 of 4 studies reporting a quadratic fit). Polyhydramnios was associated with prematurity in 2 of 4 studies (1 amniotic fluid index and 1 single deepest pocket), and oligohydramnios was associated with prematurity in 1 single deepest pocket study. Stillbirth was the only intrapartum outcome reported in more than 1 study. Perinatal outcomes associated with polyhydramnios included neonatal death (P < .05 in 1 of 2 studies), low Apgar scores (1 of 2 studies), neonatal intensive care unit admission (1 of 2 studies), and low birth weight (2 of 3 studies).
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Affiliation(s)
- Danielle L Ippolito
- Department of Clinical Investigation (D.L.I.) and Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology (M.A.L., S.K.F.-N.), Madigan Army Medical Center, Tacoma, Washington USA; Department of Obstetrics and Gynecology, Naval Medical Center, Portsmouth, Virginia USA (J.E.B.); and Department of Obstetrics and Gynecology, University of Arkansas for the Medical Sciences, Little Rock, Arkansas USA (E.F.M.)
| | - Jennifer E Bergstrom
- Department of Clinical Investigation (D.L.I.) and Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology (M.A.L., S.K.F.-N.), Madigan Army Medical Center, Tacoma, Washington USA; Department of Obstetrics and Gynecology, Naval Medical Center, Portsmouth, Virginia USA (J.E.B.); and Department of Obstetrics and Gynecology, University of Arkansas for the Medical Sciences, Little Rock, Arkansas USA (E.F.M.)
| | - Monica A Lutgendorf
- Department of Clinical Investigation (D.L.I.) and Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology (M.A.L., S.K.F.-N.), Madigan Army Medical Center, Tacoma, Washington USA; Department of Obstetrics and Gynecology, Naval Medical Center, Portsmouth, Virginia USA (J.E.B.); and Department of Obstetrics and Gynecology, University of Arkansas for the Medical Sciences, Little Rock, Arkansas USA (E.F.M.)
| | - Shannon K Flood-Nichols
- Department of Clinical Investigation (D.L.I.) and Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology (M.A.L., S.K.F.-N.), Madigan Army Medical Center, Tacoma, Washington USA; Department of Obstetrics and Gynecology, Naval Medical Center, Portsmouth, Virginia USA (J.E.B.); and Department of Obstetrics and Gynecology, University of Arkansas for the Medical Sciences, Little Rock, Arkansas USA (E.F.M.)
| | - Everett F Magann
- Department of Clinical Investigation (D.L.I.) and Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology (M.A.L., S.K.F.-N.), Madigan Army Medical Center, Tacoma, Washington USA; Department of Obstetrics and Gynecology, Naval Medical Center, Portsmouth, Virginia USA (J.E.B.); and Department of Obstetrics and Gynecology, University of Arkansas for the Medical Sciences, Little Rock, Arkansas USA (E.F.M.).
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Magann EF, Sandlin AT, Ounpraseuth ST. Amniotic fluid and the clinical relevance of the sonographically estimated amniotic fluid volume: oligohydramnios. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2011; 30:1573-1585. [PMID: 22039031 DOI: 10.7863/jum.2011.30.11.1573] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The amniotic fluid volume (AFV) is regulated by several systems, including the in-tramembranous pathway, fetal production (fetal urine and lung fluid) and uptake (fetal swallowing), and the balance of fluid movement via osmotic gradients. The normal AFV across gestation has not been clearly defined; consequently, abnormal volumes are also poorly defined. Actual AFVs can be measured by dye dilution techniques and directly measured at cesarean delivery; however, these techniques are time-consuming, are invasive, and require laboratory support, and direct measurement can only be done at cesarean delivery. As a result of these limitations, the AFV is estimated by the amniotic fluid index (AFI), the single deepest pocket, and subjective assessment of the AFV. Unfortunately, sonographic estimates of the AFV correlate poorly with dye-determined or directly measured amniotic fluid. The recent use of color Doppler sonography has not improved the diagnostic accuracy of sonographic estimates of the AFV but instead has led to overdiagnosis of oligohydramnios. The relationship between the fixed cutoffs of an AFI of 5 cm or less and a single deepest pocket of 2 cm or less for identifying adverse pregnancy outcomes is uncertain. The use of the single deepest pocket compared to the AFI to identify oligohydramnios in at-risk pregnancies seems to be a better choice because the use of the AFI leads to an increase in the diagnosis of oligohydramnios, resulting in more labor inductions and cesarean deliveries without any improvement in peripartum outcomes.
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Affiliation(s)
- Everett F Magann
- Department of Obstetrics and Gynecology, University of Arkansas for the Medical Sciences, Little Rock, AR 72205 USA.
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Magann EF, Doherty DA, Chauhan SP, Busch FWJ, Mecacci F, Morrison JC. 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; 190:164-9. [PMID: 14749654 DOI: 10.1016/s0002-9378(03)00859-7] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVE This study was undertaken to determine whether the amniotic fluid index (AFI) and single deepest pocket percentiles can reliably identify a dye-determined amniotic fluid volume. STUDY DESIGN Ultrasound measurements and dye-determined volumes were prospectively collected. Oligohydramnios predictors included AFI and single deepest pocket below the 3rd and 5th percentiles, and hydramnios predictors were based on AFI and single deepest pocket above the 95th and 97th percentiles. RESULTS Two hundred ninety-one women with singleton pregnancies participated, including 75 pregnancies (26%) with oligohydramnios and 31 pregnancies (10%) with hydramnios. The predictive ability of the AFI and single deepest pocket indices (<3rd and 5th percentiles) to identify oligohydramnios was between 11% and 27% and to identify hydramnios (>95th and 97th percentiles) ranged between 33% and 46%. The best prediction was for normal fluid volume with an accuracy of 83% to 94%. CONCLUSION Amniotic fluid indices perform best for the identifying normal AF volumes, whereas the identification of oligohydramnios or hydramnios is poor.
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Affiliation(s)
- Everett F Magann
- Department of Obstetrics and Gynecology, University of Western Australia, Perth, Australia
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