title: A systematic review of amniotic fluid assessments in twin pregnancies.
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).
authors: 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.).
authors: Danielle L
authors: DL
authors: Ippolito
authors: 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.).
authors: Jennifer E
authors: JE
authors: Bergstrom
authors: 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.).
authors: Monica A
authors: MA
authors: Lutgendorf
authors: 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.).
authors: Shannon K
authors: SK
authors: Flood-Nichols
authors: 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.). efmagann@uams.edu.
authors: Everett F
authors: EF
authors: Magann
mesh_terms: D000653:Amniotic Fluid / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D016104:Oligohydramnios / Q000000981:diagnostic imaging; D006831:Polyhydramnios / Q000000981:diagnostic imaging; D011247:Pregnancy; D011256:Pregnancy Outcome; D059285:Pregnancy, Twin; D015203:Reproducibility of Results; D014427:Twins; D016216:Ultrasonography, Prenatal / Q000379:methods*
keywords: amniotic fluid volume; obstetric ultrasound; sonography; twin pregnancies