Fetal and umbilical Doppler ultrasound in high-risk pregnancies

Cochrane Database of Systematic Reviews

Volumn 2013, Issue 11, 2013, Pages

  Alfirevic, Zarko ^a   Stampalija, Tamara ^b   Gyte, Gillian M L ^a  

^a UNIVERSITY OF LIVERPOOL   (United Kingdom)

^b INSTITUTE FOR MATERNAL AND CHILD HEALTH IRCCS BURLO GAROFOLO   (Italy)

Author keywords

[No Author keywords available]

Indexed keywords

AIR CONDITIONING; APGAR SCORE; BIRTH WEIGHT; BRAIN HEMORRHAGE; CARDIOTOCOGRAPHY; CESAREAN SECTION; DOPPLER FLOWMETRY; ELECTIVE SURGERY; EMERGENCY SURGERY; FETUS DISTRESS; GESTATIONAL AGE; HIGH RISK PREGNANCY; HOSPITAL ADMISSION; HOSPITALIZATION; HUMAN; HYPERTENSION; HYPOXIC ISCHEMIC ENCEPHALOPATHY; INTERMETHOD COMPARISON; INTRAUTERINE GROWTH RETARDATION; INTUBATION; LABOR INDUCTION; LENGTH OF STAY; LEUKOMALACIA; NEONATAL INTENSIVE CARE UNIT; NEWBORN DEATH; NEWBORN JAUNDICE; NEWBORN MORBIDITY; OUTCOME ASSESSMENT; PERINATAL DEATH; PHOTOTHERAPY; PREECLAMPSIA; PREMATURE LABOR; PRIORITY JOURNAL; RESPIRATORY DISTRESS SYNDROME; REVIEW; SEIZURE; SMALL FOR DATE INFANT; STILLBIRTH; SYSTEMATIC REVIEW; VAGINAL DELIVERY; DIAGNOSTIC IMAGING; FEMALE; FETUS ECHOGRAPHY; FETUS MONITORING; META ANALYSIS; PERINATAL MORTALITY; PREGNANCY; PROCEDURES; RANDOMIZED CONTROLLED TRIAL (TOPIC); UMBILICAL CORD; UTILIZATION; VASCULARIZATION;

CESAREAN SECTION; FEMALE; FETAL MONITORING; HUMANS; LABOR, INDUCED; PERINATAL MORTALITY; PREGNANCY; PREGNANCY, HIGH-RISK; RANDOMIZED CONTROLLED TRIALS AS TOPIC; ULTRASONOGRAPHY, PRENATAL; UMBILICAL CORD;

MLCS; MLOWN;

EID: 84900772310     PISSN: 14651858     EISSN: None     Source Type: Journal    
DOI: 10.1002/14651858.CD007529.pub3     Document Type: Review

References (99)

1. Almstrom H, Axelsson O, Cnattingius S, Ekman G, Maesel A, Ulmsten U, et al. Comparison of umbilical-artery velocimetry and cardiotocography for surveillance of small-for-gestational-age fetuses. Lancet 1992;340:936-40.
2. Almstrom H, Axelsson O, Ekman G, Ingemarsson I, Maesel A, Arstrom K, et al. Umbilical artery velocimetry may influence clinical interpretation of intrapartum cardiotocograms. Acta Obstetricia et Gynecologica Scandinavica 1995;74:526-9.
3. Marsal K, Almstrom H, Axelsson O, Cnattingius S, Ekman G, Maesel A, et al. Umbilical artery velocimetry is more effective than cardiotocography for surveillance of growth retarded fetuses. Journal of Perinatal Medicine 1991;19(Suppl 2):84.
4. Biljan M, Haddad N, McVey K, Williams J. Efficiency of continuous-wave Doppler in screening high risk pregnancies in a district general hospital (a prospective randomized study on 674 singleton pregnancies). Proceedings of 26th British Congress of Obstetrics and Gynaecology; 1992 July 7-10; Manchester, UK. 1992:6.
5. Biljan MM, McVey KP, Haddad NG. The value of continuous wave doppler assessment of fetal umbilical artery in management of "at risk" pregnancies. Proceedings of 2nd European Congress on Prostaglandins in Reproduction; 1991 April 30-May 3; The Hague, Netherlands. 1991:189.
6. Burke G, Stuart B, Crowley P, Ni Scanaill S, Drumm J. Does Doppler ultrasound alter the management of high-risk pregnancy?. Care concern and cure in perinatal medicine. 13th European Congress of Perinatal Medicine; 1992 May; Amsterdam, The Netherlands. Parthenon, 1992:597-604.
7. Burke G, Stuart B, Crowley P, Ni Scanaill S, Drumm J. Does Doppler ultrasound alter the management of high-risk pregnancy?. Journal of Perinatal Medicine 1992;20(Suppl 1):266.
8. de Rochambeau B, Jabbour N, Mellier G. Umbilical doppler velocimetry in prolonged pregnancies [La velocimetrie Doppler ombilicale dans les grossesses prolongees]. Revue Francaise de Gynecologie et d Obstetrique 1992;87(5):289-94.
9. Giles W, Bisits A, O'Callaghan S. The doppler assessment in multiple pregnancy study (damp) and metaanalyses of doppler and twins. American Journal of Obstetrics and Gynecology 2000;182(1 Pt 2):S17.
10. Giles W, Bisits A, O'Callaghan S, Gill A. The doppler assessment in multiple pregnancy randomised controlled trial of ultrasound biometry versus umbilical artery doppler ultrasound and biometry in twin pregnancy. BJOG: an international journal of obstetrics and gynaecology 2003;110(6):593-7.
11. Haley J, Tuffnell DJ, Johnson N. Randomised controlled trial of cardiotocography versus umbilical artery Doppler in the management of small for gestational age fetuses. British Journal of Obstetrics and Gynaecology 1997;104(4):431-5.
12. Hofmeyr GJ, Pattinson R, Buckley D, Jennings J, Redman CWG. Umbilical artery resistance index as a screening test for fetal well-being. II. Randomized feasibility study. Obstetrics & Gynecology 1991;78:359-62.
13. Johnstone FD, Prescott R, Hoskins P, Greer IA, McGlew T, Compton M. The effect of introduction of umbilical Doppler recordings to obstetric practice. British Journal of Obstetrics and Gynaecology 1993;100:733-41.
14. Neales K. A randomised controlled study to assess the use of Doppler ultrasound in the management of patients with intrauterine growth retardation. Personal communication 1994.
15. Newnham JP, O'Dea MRA, Reid KP, Diepeveen DA. Doppler flow velocity waveform analysis in high risk pregnancies: a randomized controlled trial. British Journal of Obstetrics and Gynaecology 1991;98:956-63.
16. Nienhuis SJ. Costs and effects of Doppler ultrasound measurements in suspected intrauterine growth retardation. A randomised clinical trial [thesis]. Maastricht: Universitaire Pers Maastricht, 1995.
17. Nienhuis SJ, Ruissen CJ, Hoogland HJ, Gerver JW, Vles J, de Haan J. Cost-effectiveness of a doppler policy in suspected intrauterine growth retardation - a randomized controlled trial. Proceedings of 13th World Congress of Gynaecology and Obstetrics (FIGO); 1991 Sept 15-20; Singapore. 1991:32.
18. Nienhuis SJ, Vles JS, Gerver WJ, Hoogland HJ. Doppler ultrasonography in suspected intrauterine growth retardation: a randomized clinical trial. Ultrasound in Obstetrics & Gynecology 1997;9(1):6-13.
19. Ruissen CJ, Nienhuis SJ, Hoogland HJ, Vles JFH, Gerver WJ, De Haan J. Cost-effectiveness of a Doppler based policy of suspected intrauterine growth retardation - a randomised controlled trial. Journal of Maternal Fetal Investigation 1992;1:126.
20. Nimrod C, Yee J, Hopkins C, Pierce P, Lange I, Fick G, et al. The utility of pulsed Doppler studies in the evaluation of postdate pregnancies. Journal of Maternal Fetal Investigation 1992;1:127.
21. Norman K, Pattinson RC, Carstens E. Doppler velocimetry in recurrent pregnancy loss: is there a role?. Proceedings of 11th Conference on Priorities in Perinatal Care in South Africa; 1992 March; Caledon, South Africa. 1992:71-4.
22. Ott WJ, Mora G, Arias F, Sunderji S, Sheldon G. Comparison of the modified biophysical profile to a new biophysical profile incorporating the middle cerebral artery to umbilical artery velocity flow systolic/diastolic ratio. American Journal of Obstetrics and Gynecology 1998;178(6):1346-53.
23. Pattinson R, Norman K, Odendaal HJ. Management of fetuses suspected of IUGR but with EDVs of the umbilical artery: a randomised controlled trial. Proceedings of 26th British Congress of Obstetrics and Gynaecology; 1992 July 7-10; Manchester, UK. 1992:5.
24. Pattinson RC, Norman K, Odendaal HJ. The role of Doppler velocimetry in the management of high risk pregnancies. British Journal of Obstetrics and Gynaecology 1994;101:114-20.
25. Pattinson RC, Norman K, Odendaal HJ. The role of doppler velocimetry in the management of pregnancies: a randomized controlled trial. Proceedings of 11th Conference on Priorities in Perinatal Care in South Africa; 1992 March; Caledon, South Africa. 1992:59-63.
26. Trudinger BJ, Cook CM, Giles WB, Connelly AJ, Thompson RS. Umbilical artery flow velocity waveforms in high-risk pregnancy: randomised controlled trial. Lancet 1987;1:188-90.
27. Lilford RJ. Fetal assessment in laboratory vs standard management of high risk pregnancy. Personal communication 1989.
28. Tyrrell SN, Lilford RJ, MacDonald HN, Nelson EJ, Porter J, Gupta JK. Randomized comparison of routine vs highly selective use of Doppler ultrasound and biophysical scoring to investigate high risk pregnancies. British Journal of Obstetrics and Gynaecology 1990;97:909-16.
29. Williams K, Farquharson D, Bebbington M, Dansereau J, Galerneau F, Wilson RD, et al. A randomized controlled clinical trial comparing non stress testing versus doppler velocimetry as a screening test in a high risk population [abstract]. American Journal of Obstetrics and Gynecology 2000;182(1 Pt 2):S109.
30. Williams KP, Farquharson DF, Bebbington M, Dansereau J, Galerneau F, Wilson RD, et al. Screening for fetal well-being in a high-risk pregnant population comparing the nonstress test with umbilical artery doppler velocimetry: a randomized controlled clinical trial. American Journal of Obstetrics and Gynecology 2003;188(5):1366-71.
31. Davies JA, Gallivan S, Spencer JAD. Randomised controlled trial of doppler ultrasound screening of placental perfusion during pregnancy. Lancet 1992;340:1299-303.
32. Gonsoulin W. Umbilical artery Doppler waveform analysis: a randomized study on effect on outcome. American Journal of Obstetrics and Gynecology 1991;164:370.
33. Mason GC, Lilford RJ, Porter J, Nelson E, Tyrell S. Randomised comparison of routine vs highly selective use of Doppler ultrasound in low risk pregnancies. British Journal of Obstetrics and Gynaecology 1993;100:130-3.
34. McCowan LME, Harding J, Roberts AB, Barker S, Townend K. Perinatal morbidity in small for gestational age fetuses in relation to umbilical doppler. Proceedings of the 14th Annual Congress of the Australian Perinatal Society in conjunction with the New Zealand Perinatal Society; 1996 March 24-27; Adelaide, Australia. 1996:P10.
35. McParland P, Pearce JM. Doppler blood flow in pregnancy. Placenta 1988;9:427-50.
36. Newnham JP, Evans SF, Michael CA, Stanley FJ, Landau LI. Effects of frequent ultrasound during pregnancy: a randomised controlled trial. Lancet 1993;342:887-91.
37. Omtzigt AWJ. Clinical value of umbilical doppler velocimetry [thesis]. Utrecht: University of Utrecht, 1990.
38. Omtzigt AWJ, Bruinse HW, Reuwer PJHM. A randomized controlled trial on the clinical value of umbilical Doppler velocimetry. I. Obstetrical management. Proceedings of 12th European Congress of Perinatal Medicine; 1990 Sept 11-14; Lyon, France. 1990:210.
39. Omtzigt AWJ, Bruinse HW, Reuwer PJHM. A randomized controlled trial on the clinical value of umbilical Doppler velocimetry: neonatal outcome. Proceedings of 12th European Congress of Perinatal Medicine; 1990 Sept 11-14; Lyon, France. 1990:189.
40. Omtzigt AWJ, Reuwer PJHM, Bruinse HW. A randomized controlled trial on the clinical value of umbilical Doppler velocimetry in antenatal care. American Journal of Obstetrics and Gynecology 1994;170:625-34.
41. Pearce JM. The application of uteroplacental waveforms to complicated pregnancies. Doppler Ultrasound in Perinatal Medicine. Oxford: Oxford University Press, 1992:159-77.
42. Schneider KTM, Renz S, Furstenau U, Amberg-Wendland D, Prochaska D, GraeffH. Doppler flow measurements as a screening method during pregnancy: is it worth the effort?. Journal of Maternal Fetal Investigation 1992;1:125.
43. Whittle MJ, Hanretty KP, Primrose MH, Neilson JP. Screening for the compromised fetus: a randomized trial of umbilical artery velocimetry in unselected pregnancies. American Journal of Obstetrics and Gynecology 1994;170:555-9.
44. Cambridge Consortium. Trial of umbilical and fetal flow in Europe (TRUFFLE) (ongoing trial). National Research Register (www.nrr.nhs.uk) (accessed 6 July 2006).
45. Lees C, Baumgartner H. The TRUFFLE study - a collaborative publicly funded project from concept to reality: how to negotiate an ethical, administrative and funding obstacle course in the European Union. Ultrasound in Obstetrics and Gynecology 2005;25:105-7.
46. Al-Ghazali WH, Chapman MG, Rissik JM, Allan LD. The significance of absent end-diastolic flow in the umbilical artery combined with reduced fetal cardiac output estimation in pregnancies at high risk for placental insufficiency. Journal of Obstetrics and Gynaecology 1990;10:271-5.
47. Alfirevic Z, Neilson JP. Doppler ultrasonography in high-risk pregnancies: systematic review with meta-analysis. American Journal of Obstetrics and Gynecology 1995;172:1379-87.
48. Alfirevic Z, Roberts D, Martlew V. How strong is the association between maternal thrombophilia and adverse pregnancy outcome? A systematic review. European Journal Obstetetrics & Gynecology and Reproductive Biology 2002;101(1):6-14.
49. Alfirevic Z, Stampalija T, Gyte GML. Fetal and umbilical Doppler ultrasound in normal pregnancy. Cochrane Database of Systematic Reviews 2010, Issue 8. [DOI: 10.1002/14651858.CD001450.pub3]
50. Almstrom H, Axelsson O, Ekman G, Ingemarsson I, Maesel A, Arstrom K, et al. Umbilical artery velocimetry may influence clinical interpretation of intrapartum cardiotocograms. Acta Obstetricia et Gynecologica Scandinavica 1995;74:526-9.
51. Baschat AA, Gembruch U, Harman CR. The sequence of changes in Doppler and biophysical parameters as severe fetal growth restriction worsens. Ultrasound in Obstetrics & Gynecology 2001;18:571-7.
52. Baschat AA, Gembruch U. Evaluation of the fetal coronary circulation. Ultrasound in Obstetrics & Gynecology 2002;20:405-12.
53. Bernstein IM, Horbar JD, Badger GJ, Ohlsson A, Golan A. Morbidity and mortality among very-low-birth-weight neonates with intrauterine growth restriction. The Vermont Oxford Network. American Journal of Obstetrics and Gynecology 2000;182:198-206.
54. Bilardo CM, Nicolaides KH, Campbell S. Doppler measurements of fetal and uteroplacental circulations: relationship with umbilical venous blood gases measured at cordocentesis. American Journal of Obstetrics and Gynecology 1990;162:115-20.
55. Bilardo CM, Wolf H, Stigter RH, Ville Y, Baez E, Visser GHA, et al. Relationship between monitoring parameters and outcome in severe, early intrauterine growth restriction. Ultrasound in Obstetrics & Gynecology 2004;23:119-25.
56. Anonymous. Retraction of articles. British Journal of Obstetrics and Gynaecology 1995;102(11):853.
57. Bricker L, Neilson JP. Routine Doppler ultrasound in pregnancy. Cochrane Database of Systematic Reviews 2007, Issue 2. [DOI: 10.1002/14651858.CD001450.pub2]
58. Burns PN. Principles of Doppler and color flow. Radiology in Medicine 1993;85:3-16.
59. Cheema R, Dubiel M, Breborowicz G, Gudmundsson S. Fetal cerebral venous Doppler velocimetry in normal and high-risk pregnancy. Ultrasound in Obstetrics & Gynecology 2004;24:147-53.
60. Chen JF, Fowlkes JB, Carson PL, Rubin JM, Adler RS. Autocorrelation of integrated power Doppler signals and its application. Ultrasound in Medicine and Biology 1996;22:1053-7.
61. Moher D, Schulz KF, Altman DG. The CONSORT statement: revised recommendations for improving the quality of reports of parallel-group randomised trials. Lancet 2001;357(9263):1191-4.
62. Deeks JJ, Altman DG, Bradburn MJ. Statistical methods for examining heterogeneity and combining results from several studies in meta-analysis. In: Egger M, Davey Smith G, Altman DJ editor(s). Systematic Reviews in Health Care: Meta-Analysis in Context. London: BMJ, 2001.
63. Devane D, Begley CM, Clarke M, Horey D, OBoyle C. Evaluating maternity care: a core set of outcome measures. Birth 2007;34(2):164-72.
64. Egger M, Smith GD, Schneider M, Minder C. Bias in meta-analysis detected by a simple, graphical test. BMJ 1997;315:629-34.
65. Ferrazzi E, Bozzo M, Rigano S, Bellotti M, Morabito A, Pardi G, et al. Temporal sequence of abnormal Doppler changes in the peripheral and central circulatory systems of the severely growth-restricted fetus. Ultrasound in Obstetrics & Gynecology 2002;19:140-6.
66. Figueras F, Eixarch E, Gratacos E, Gardosi J. Predictiveness of antenatal umbilical artery Doppler for adverse pregnancy outcome in small-for-gestational-age babies according to customised birthweight centiles: population-based study. BJOG: an international journal of obstetrics and gynaecology 2008;115:590-4.
67. Fisk NM, Smith RP. Fetal growth restriction; small for gestational age. In: Chamberlain G, Steer P editor(s). Turnbull's Obstetrics. 3rd Edition. Edinburgh: Churchill Livingstone, 2001:197-209.
68. Fitzgerald DE, Drumm JE. Non-invasive measurement of the human circulation using ultrasound: a new method. British Medical Journal 1977;2:1450-1.
69. Gates S, Brocklehurst P. How should randomised trial including multiple pregnancies be analysed?. BJOG: an international journal of obstetrics and gynaecology 2004;111:213-9.
70. Giles WB, Trudinger BJ, Baird PJ. Fetal umbilical artery flow velocity waveforms and placental resistance: pathological correlation. British Journal of Obstetrics and Gynaecology 1985;92:31-8.
71. Graves CR. Antepartum fetal surveillance and timing of delivery in the pregnancy complicated by diabetes mellitus. Clinical Obstetrics and Gynecology 2007;50(4):1007-13.
72. Greer IA. Thrombosis in pregnancy: maternal and fetal issues. Lancet 1999;353(9160):1258-65.
73. GRIT Study Group. A randomised trial of timed delivery for the compromised preterm fetus: short term outcomes and Bayesian interpretation. BJOG: an international journal of obstetrics and gynaecology 2002;110:27-32.
74. GRIT study group. Infant wellbeing at 2 years of age in the Growth Restriction Intervention Trial (GRIT): multicentred randomised controlled trial. Lancet 2004;364:513-20.
75. Harbord RM, Egger M, Sterne JA. A modified test for small-study effects in meta-analyses of controlled trials with binary endpoints. Statistics in Medicine 2006;25:3443-57.
76. Hecher K, Bilardo CM, Stigter RH, Ville Y, Hackeloer BJ, Kok HJ, et al. Monitoring of fetuses with intrauterine growth restriction: a longitudinal study. Ultrasound in Obstetrics & Gynecology 2001;18:564-70.
77. Higgins JPT, Green S, editors. Cochrane Handbook for Systematic Reviews of Interventions Version 5.0.0 [updated February 2008]. The Cochrane Collaboration, 2008. Available from www.cochrane-handbook.org.
78. Higgins JPT, Thompson SG, Spiegelhalter DJ. A re-evaluation of random-effects meta-analysis. Journal of the Royal Statistical Society, Series A 2009;172:137-59.
79. Higgins JPT, Green S, editors. Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [updated March 2011]. The Cochrane Collaboration, 2011. Available from www.cochrane-handbook.org.
80. Lalor JG, Fawole B, Alfirevic Z, Devane D. Biophysical profile for fetal assessment in high risk pregnancies. Cochrane Database of Systematic Reviews 2008, Issue 1. [DOI: 10.1002/14651858.CD000038.pub2]
81. Mari G. Doppler ultrasonography in obstetrics: from the diagnosis of fetal anemia to the treatment of intrauterine growth-restricted fetuses. American Journal of Obstetrics and Gynecology 2009;200(6):613.e1-613.e9.
82. Mires GJ, Patel NB, Dempster J. Review: The value of fetal umbilical artery flow velocity waveforms in the prediction of adverse fetal outcome in high risk pregnancies. Journal of Obstetrics and Gynaecology 2000;10:261-70.
83. Neilson JP. Doppler ultrasound. British Journal of Obstetrics and Gynaecology 1987;94:929-34.
84. Nicholaides KH, Bilardo CM, Soothill PW, Campbell S. Absence of end diastolic frequencies in umbilical artery: a sign of fetal hypoxia and acidosis. BMJ 1988;297(6655):1026-7.
85. Nienhuis SJ. Costs and effects of Doppler ultrasound measurements in suspected intrauterine growth retardation. A randomised clinical trial [thesis]. Maastricht: Universitaire Pers Maastricht, 1995.
86. Ortibus E, Lopriore E, Deprest J, Vandenbussche FP, Walther FJ, Diemert A, et al. The pregnancy and long-term neurodevelopmental outcome of monochorionic diamniotic twin gestations: a multicenter prospective cohort study from the first trimester onward. American Journal of Obstetrics and Gynecology 2009;200(5):494.e1-494.e8.
87. Owen P. Fetal assessment in the third trimester: fetal growth and biophysical methods. In: Chamberlain G, Steer P editor(s). Turnbull's Obstetrics. 3rd Edition. Edinburgh: Churchill Livingstone, 2001.
88. Pattison N, McCowan L. Cardiotocography for antepartum fetal assessment. Cochrane Database of Systematic Reviews 1999, Issue 1. [DOI: 10.1002/14651858.CD001068]
89. The Nordic Cochrane Centre: The Cochrane Collaboration. Review Manager (RevMan). 5.0. Copenhagen: The Nordic Cochrane Centre: The Cochrane Collaboration, 2008.
90. The Nordic Cochrane Centre, The Cochrane Collaboration. Review Manager (RevMan). 5.2. Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, 2012.
91. Stampalija T, Gyte GML, Alfirevic Z. Utero-placental Doppler ultrasound for improving pregnancy outcome. Cochrane Database of Systematic Reviews 2010, Issue 9. [DOI: 10.1002/14651858.CD008363.pub2]
92. Thompson RS, Trudinger BJ. Doppler waveform pulsatility index and resistance, pressure and flow in the umbilical placental circulation: an investigation using a mathematical model. Ultrasound in Medicine and Biology 1990;16:449.
93. Trudinger BJ, Giles WB, Cook CM, Bombardieri J, Collins L. Fetal umbilical artery flow velocity waveforms and placental resistance: clinical significance. British Journal of Obstetrics and Gynaecology 1985;92:23-30.
94. Trudinger BJ, Giles WB, Cook CM. Uteroplacental blood flow velocity-time waveform in normal and complicated pregnancy. British Journal of Obstetrics and Gynaecology 1985;92:39-45.
95. Weiner CP. The relationship between the umbilical artery systolic/diastolic ratio and umbilical blood gas measurements in specimens obtained by cordocentesis. American Journal of Obstetrics and Gynecology 1990;162:1198-202.
96. Westergaard HB, Langhoff-Roos J, Lingman G, Marsal K, Kreiner S. A critical appraisal of the use of umbilical artery Doppler ultrasound in high-risk pregnancies: use of meta-analyses in evidence-based obstetrics. Ultrasound in Obstetrics & Gynecology 2001;17:466-76.
97. Alfirevic Z, Stampalija T, Gyte GML. Fetal and umbilical Doppler ultrasound in high-risk pregnancies. Cochrane Database of Systematic Reviews 2010, Issue 1. [DOI: 10.1002/14651858.CD007529.pub2]
98. Neilson JP, Alfirevic Z. Doppler ultrasound for fetal assessment in high risk pregnancies. Cochrane Database of Systematic Reviews 1995, Issue 1. [DOI: 10.1002/14651858.CD000073]
99. Neilson JP, Alfirevic Z. Doppler ultrasound for fetal assessment in high risk pregnancies. Cochrane Database of Systematic Reviews 1996, Issue 4. [DOI: 10.1002/14651858.CD000073.pub2]