Ultrasound for fetal assessment in early pregnancy

Cochrane Database of Systematic Reviews

Volumn 2015, Issue 7, 2015, Pages

  Whitworth, Melissa ^a   Bricker, Leanne ^b   Mullan, Clare ^a  

^a ST MARY S HOSPITAL   (United Kingdom)

^b Abu Dhabi Health Services Company SEHA   (United Arab Emirates)

Author keywords

[No Author keywords available]

Indexed keywords

CHILD DEATH; FETUS DISEASE; FETUS ECHOGRAPHY; FETUS MALFORMATION; FETUS OUTCOME; FIRST TRIMESTER PREGNANCY; GESTATIONAL AGE; HUMAN; LABOR INDUCTION; MENTAL DEVELOPMENT; MULTIPLE PREGNANCY; PERINATAL DEATH; PHYSICAL DEVELOPMENT; PRIORITY JOURNAL; REVIEW; STILLBIRTH; SYSTEMATIC REVIEW; CONGENITAL DISORDER; ECHOGRAPHY; FEMALE; FETUS MONITORING; META ANALYSIS; NEWBORN; PERINATAL MORTALITY; PREGNANCY; PROCEDURES; SECOND TRIMESTER PREGNANCY;

CONGENITAL ABNORMALITIES; FEMALE; FETAL MONITORING; GESTATIONAL AGE; HUMANS; INFANT, NEWBORN; PERINATAL MORTALITY; PREGNANCY; PREGNANCY TRIMESTER, FIRST; PREGNANCY TRIMESTER, SECOND; PREGNANCY, MULTIPLE; ULTRASONOGRAPHY, PRENATAL;

EID: 84957409844     PISSN: None     EISSN: 1469493X     Source Type: Journal    
DOI: 10.1002/14651858.CD007058.pub3     Document Type: Review

References (97)

1. Crowther CA. Trial to assess whether ultrasound examination at the booking antenatal visit reduces the number of repeat screenings and results in earlier diagnosis of non-viable pregnancy/congenital abnormality. Personal communication 1992.
2. Crowther CA, Kornman L, O'Callaghan S, George K, Furness M, Willson K. Is an ultrasound assessment of gestational age at the first antenatal visit of value? A randomised clinical trial. British Journal of Obstetrics and Gynaecology 1999;106(12):1273-9.
3. Eik-Nes SH. Effects of routine two-stage ultrasound screening in pregnancy: the Alesund randomised controlled trial revisited. Personal communication 1984.
4. Eik-Nes SH, Okland O. Ultrasound screening of pregnant women - a prospective randomized study. Diagnostic Ultrasound Imaging in Pregnancy. NIH Publication No.84-667. Washington: US Department of Health and Human Services, 1984:207-13.
5. Eik-Nes SH, Okland O, Aure JC, Ulstein M. Ultrasound screening in pregnancy: a randomised controlled trial. Lancet 1984;1:1347.
6. Eik-Nes SH, Salvesen KA, Okland O, Vatten LJ. Routine ultrasound fetal examination in pregnancy: the 'Alesund' randomized controlled trial. Ultrasound in Obstetrics & Gynecology 2000;15(6):473-8.
7. Salvesen KA. Routine Ultrasonography in Utero and Development in Childhood - a Randomized Controlled Follow-up Study [MSc thesis]. University of Trondheim, 1993.
8. Leivo T, Tuominen R, Saari-Kemppainen A, Ylostalo P, Karjalainen O, Heinonen OP. Cost-effectiveness of one-stage ultrasound screening in pregnancy: a report from the Helsinki ultrasound trial. Ultrasound in Obstetrics & Gynecology 1996;7(5):309-14.
9. Saari-Kemppainen A. Use of antenatal care services in a controlled ultrasound screening trial. Acta Obstetricia et Gynecologica Scandinavica 1995;74:12-4.
10. Saari-Kemppainen A, Karjalainen O, Ylostalo P. A randomised study of ultrasound screening during pregnancy. 12th FIGO World Congress of Gynecology and Obstetrics; 1988 October 23-28; Brazil. 1988:247-8.
11. Saari-Kemppainen A, Karjalainen O, Ylostalo P. Ultrasound screening and perinatal mortality: a controlled clinical trial. Proceedings of 12th European Congress of Perinatal Medicine; 1990 Sept 11-14; Lyon, France. 1990:36.
12. Saari-Kemppainen A, Karjalainen O, Ylostalo P, Heinonen OP. Fetal anomalies in a controlled one-stage ultrasound screening trial. A report from the Helsinki Ultrasound Trial. Journal of Perinatal Medicine 1994;22:279-89.
13. Saari-Kemppainen A, Karjalainen O, Ylostalo P, Heinonen OP. Ultrasound screening and perinatal mortality: controlled trial of systematic one-stage screening in pregnancy. Lancet 1990; Vol. 336:387-91.
14. van Dyk B, Motto JA, Buchmann EJ. Routine second-trimester ultrasound for low risk pregnancies in a South African community. International Journal of Gynecology & Obstetrics 2007;98(3):257-8.
15. van Dyk B, Motto JA, Buchmann EJ. The value of routine mid-trimester ultrasound in low-risk pregnancies at primary care level. Health SA Gesondheid 2008;13(4):41-9.
16. Bennett MJ, Little G, Dewhurst J, Chamberlain GVP. Predictive value of ultrasound measurement in early pregnancy: a randomized controlled trial. British Journal of Obstetrics and Gynaecology 1982;89:338-41.
17. Ewigman B, LeFevre M, Hesser J. A randomized trial of routine prenatal ultrasound. Obstetrics & Gynecology 1990;76:189-94.
18. Salvesen KA. Routine ultrasonography in utero and development in childhood - a randomized controlled follow-up study. Acta Obstetricia et Gynecologica Scandinavica 1995;74:166-7.
19. Salvesen KA, Bakketeig LS, Eik-Nes SH, Undheim JO, Okland O. Routine ultrasonography in utero and school performance at age 8-9 years. Lancet 1992;339:85-9.
20. Salvesen KA, Jacobsen G, Vatten LJ, Eik-Nes SH, Bakketeig LS. Routine ultrasonography in utero and subsequent growth during childhood. Ultrasound in Obstetrics & Gynecology 1993;3:6-10.
21. Salvesen KA, Vatten LJ, Eik-Nes SH, Hugdahl K, Bakketeig LS. Routine ultrasonography in utero and subsequent handedness and neurological development. BMJ 1993;307:159-64.
22. Salvesen KA, Vatten LJ, Jacobsen G, Eik-Nes SH, Okland O, Molne K, et al. Routine ultrasonography in utero and subsequent vision and hearing at primary school age. Ultrasound in Obstetrics & Gynecology 1992;2:243-7.
23. Harrington DJ, MacKenzie IZ, Thompson K, Fleminger M, Greenwood C. Does a first trimester dating scan using crown rump length measurement reduce the rate of induction of labour for prolonged pregnancy? An uncompleted randomised controlled trial of 463 women. BJOG: an international journal of obstetrics and gynaecology 2006;113(2):171-6.
24. Harrington DJ, Mackenzie IZ, Chamberlain P, Greenwood C. Does a first trimester crown-rump length (CRL) measurement reduce the rate of elective timed delivery for post dates? A randomised control trial [abstract]. Journal of Obstetrics and Gynaecology 2004;24(Suppl 1):S22.
25. MacKenzie I. The effect of first trimester crown rump length (CRL) measurement rates of labour for postdates. Research Findings Register www.refer.nhs.uk (accessed 7 March 2006).
26. Crane JP, LeFevre ML, Winborn RC, Evans JK, Ewigman G, Bain RP, et al. A randomized trial of prenatal ultrasonographic screening: impact on the detection, management, and outcome of anomalous fetuses. American Journal of Obstetrics and Gynecology 1994;171:392-9.
27. Ewigman BG, Crane JP, Frigoletto FD, LeFevre ML, Bain RP, McNellis D, et al. Effect of prenatal ultrasound screening on perinatal outcome. New England Journal of Medicine 1993;329:821-7.
28. Frigoletto FD Jr, Ewigman BG, Crane JP, LeFevre ML, Bain RP, McNellis D. Routine ultrasound screening for all pregnant women: does it make a difference?. Acta Obstetrica Et Gynaecologica Japonica 1997;49:452.
29. Harlow BL, Frigoletto FD, Cramer DW, Evans JK, Bain RP, Ewigman B, et al. Epidemiologic predictors of Cesarean section in nulliparous patients at low risk. American Journal of Obstetrics and Gynecology 1995;172:156-62.
30. LeFevre ML, Bain RP, Ewigman BG, Frigoletto FD, Crane JP, McNellis D, et al. A randomized trial of prenatal ultrasonographic screening: impact on maternal management and outcome. American Journal of Obstetrics and Gynecology 1993;169:483-9.
31. LeFevre ML, Evans JK, Ewigman B. Is smoking an indication for prenatal ultrasonography? RADIUS Study Group;. Archives of Family Medicine 1995; Vol. 4:120-3.
32. Axelsson O. Estimation of gestational age by measurement of the biparietal diameter in the second trimester: preliminary results of a randomized trial. Proceedings of 6th Congress of the European Federation of Societies for Ultrasound in Medicine and Biology; 1987 June 14-18; Helsinki, Finland. 1987.
33. Kieler H, Ahlsten G, Haglund B, Salvesen K, Axelsson O. Routine ultrasound screening in pregnancy and the children's subsequent neurologic development. Obstetrics & Gynecology 1998;91(5 Pt 1):750-6.
34. Kieler H, Axelsson O, Haglund B, Nilsson S, Salvesen KA. Routine ultrasound screening in pregnancy and the children's subsequent handedness. Early Human Development 1998;50(2):233-45.
35. Kieler H, Haglund B, Waldenstrom U, Axelsson O. Routine ultrasound screening in pregnancy and the children's subsequent growth, vision and hearing. British Journal of Obstetrics and Gynaecology 1997;104(11):1267-72.
36. Stalberg K, Axelsson O, Haglund B, Hultman CM, Lambe M, Kieler H. Prenatal ultrasound exposure and school achievement in teenagers; follow-up of a randomized controlled trial. Ultrasound in Obstetrics and Gynecology 2008;32(3):306.
37. Stålberg K, Axelsson O, Haglund B, Hultman CM, Lambe M. Prenatal ultrasound exposure and children's school performance at age 15-16: follow-up of a randomized controlled trial. Ultrasound in Obstetrics and Gynecology 2009;34:297-303.
38. Waldenstrom U, Axelsson O, Nilsson S. Ultrasonic dating of pregnancies: effect on incidence of SGA diagnoses. A randomised controlled trial. Early Human Development 1992; Vol. 30:75-9.
39. Waldenstrom U, Axelsson O, Nilsson S, Eklund G, Fall O, Lindeberg S, et al. Effects of routine one-stage ultrasound screening in pregnancy: a randomised controlled trial. Lancet 1988;2:585-8.
40. Bakketeig LS, Jacobsen G, Brodtkorb CJ, Eriksen BC, Eik-Nes SH, Ulstein MK, et al. Randomised controlled trial of ultrasonographic screening in pregnancy. Lancet 1984;2:207-10.
41. Geerts L, Brand E, Theron GB. Routine obstetric ultrasound examinations in South Africa: Cost and effect on perinatal outcome - A prospective randomised controlled trial. Proceedings of the 14th Conference on Priorities in Perinatal Care in South Africa; 1995 March 7-10; South Africa. 1995:130-3.
42. Geerts LTGM, Brand EJ, Theron GB. Routine obstetric ultrasound examinations in South Africa: cost and effect on perinatal outcome - a prospective randomised controlled trial. British Journal of Obstetrics and Gynaecology 1996;103:501-7.
43. Belanger K, Hobbins JC, Muller JP, Howard S. Neurological testing in ultrasound exposed infants. American Journal of Obstetrics and Gynecology 1996;174(1 Pt 2):413.
44. Bennett K, Crane J, O'Shea P, Lacelle J, Hutchens D, Copel J. Combined first and second trimester ultrasound screening is effective in reducing postterm labor induction rates: a randomized controlled trial [abstract]. American Journal of Obstetrics and Gynecology 2002;187(6 Pt 2):S68.
45. Bennett KA, Crane JMG, O'Shea P, Lacelle J, Hutchens D, Copel JA. First trimester ultrasound screening is effective in reducing postterm labor induction rates: a randomized controlled trial. American Journal of Obstetrics and Gynecology 2004;190:1077-81.
46. DuffG. A randomised controlled trial in a hospital population of ultrasound measurement screening for the small for dates baby. Proceedings of 2nd International Scientific Meeting of the Royal College of Obstetricians and Gynaecologists; 1993 Sept 7-10; Hong Kong. 1993:90.
47. DuffGB. A randomized controlled trial in a hospital population of ultrasound measurement screening for the small for dates baby. Australian and New Zealand Journal of Obstetrics and Gynaecology 1993;33:374-8.
48. Georgsson Ohman S, Waldenstrom U, Georgsson Ohman S, Waldenstrom U. Effect of first-trimester ultrasound screening for Down syndrome on maternal-fetal attachment--a randomized controlled trial. Sexual & Reproductive Healthcare 2010;1(3):85-90.
49. Chen M, Lee CP, Lam YH, Tang RY, Chan BC, Wong SF, et al. Comparison of nuchal and detailed morphology ultrasound examinations in early pregnancy for fetal structural abnormality screening: a randomized controlled trial. Ultrasound in Obstetrics and Gynecology 2008;31(2):136-46.
50. Larsen T, Larsen JK, Petersen S, Greisen G. Detection of small-for-gestational-age fetuses by ultrasound screening in a high risk population: a randomized controlled study. British Journal of Obstetrics and Gynaecology 1992;99:469-74.
51. Leung KY, Ngai CS, Lee A, Chan HY, Leung WC, Lee CP, et al. The effects on maternal anxiety of two-dimensional versus two- plus three-/four-dimensional ultrasound in pregnancies at risk of fetal abnormalities: A randomized study. Ultrasound in Obstetrics and Gynecology 2006;28(3):249-54.
52. Owen P, Donnet L, Ogston S, Christie A, Patel N, Howie P. A study of fetal growth velocity. British Journal of Obstetrics and Gynaecology 1994;101:270.
53. Righetti PL, Dell'Avanzo M, Grigio M, Nicolini U. Maternal/paternal antenatal attachment and fourth-dimensional ultrasound technique: a preliminary report. British Journal of Psychology 2005;96(Pt 1):129-37.
54. Rustico MA, Mastromatteo C, Grigio M, Maggioni C, Gregori D, Nicolini U. Two-dimensional vs. two- plus four-dimensional ultrasound in pregnancy and the effect on maternal emotional status: a randomized study. Ultrasound in Obstetrics & Gynecology 2005;25:468-72.
55. Georgsson Ohman S, Saltvedt S, Grunewald C, Waldenstrom U. Does fetal screening affect the women's worries about the health of their baby? A randomized controlled trial of ultrasound screening for Down's syndrome versus routine ultrasound screening. Acta Obstetricia et Gynecologica Scandinavica 2004;83:634-40.
56. Saltvedt S, Almstrom H, Kublick M, Reilly M, Valentin L, Grunewald C. Ultrasound dating at 12-14 or 15-20 weeks of gestation? A prospective cross-validation of established dating formulae in a population of in-vitro fertilized pregnancies randomized to early or late dating scan. Ultrasound in Obstetrics & Gynecology 2004;24:42-50.
57. Saltvedt S, Almstrom H, Kublickas M, Valentin L, Bottinga R, Bui TH, et al. Screening for Down syndrome based on maternal age or fetal nuchal translucency: a randomized controlled trial in 39 572 pregnancies. Ultrasound in Obstetrics and Gynecology 2005;25:537-45.
58. Saltvedt S, Almstrom H, Kublickas M, Valentin L, Grunewald C. Detection of malformations in chromosomally normal fetuses by routine ultrasound at 12 or 18 weeks of gestation - a randomised controlled trial in 39, 572 pregnancies. BJOG: an international journal of obstetrics and gynaecology 2006;113(6):664-74.
59. Westin M, Saltvedt S, Bergman G, Kublickas M, Almstrom H, Grunewald C, et al. Routine ultrasound examination at 12 or 18 gestational weeks for prenatal detection of major congenital heart malformations? A randomised controlled trial comprising 36, 299 fetuses. BJOG: an international journal of obstetrics and gynaecology 2006;113(6):675-82.
60. Schifano M, Luchi C, Sceusa F, Nanini C, Pepe A, Mannella P, et al. Women's attitude towards ultrasound scanning in the first trimester of pregnancy: two-dimensional versus two-plus four-dimensional ultrasound effects on maternal emotional status. Journal of Psychosomatic Obstetrics and Gynecology 2010;31(s1):65.
61. Schwarzler P, Senat MV, Holden D, Bernard JP, Masroor T, Ville Y. Feasibility of the second-trimester ultrasound examination in an unselected population at 18, 20 or 22 weeks of pregnancy: a randomised trial. Ultrasound in Obstetrics & Gynecology 1999;14:92-7.
62. Votino C, Kacem Y, Dobrescu O, Dessy H, Cos T, Foulon W, et al. Use of a high-frequency linear transducer and MTI filtered color flow mapping in the assessment of fetal heart anatomy at the routine 11 to 13 + 6-week scan: a randomized trial. Ultrasound in Obstetrics & Gynecology 2012;39(2):145-51.
63. Wald NJ. Randomised controlled trial of routine dating ultrasound in pregnancy. Personal communication 1988.
64. Deverill M, Snaith V, Howel D, Hewison J, Sturgiss S, Robson S. The Newcastle randomised controlled trial of early screening for fetal abnormality - women's preferences for early information on fetal status and cost-effectiveness analysis [abstract]. Journal of Obstetrics and Gynaecology 2004;24(Suppl 1):S20.
65. Snaith V, Howel D, Deverill M, Hewison J, Sturgiss S, Robson S. The Newcastle randomised controlled trial of early ultrasound screening for fetal abnormality (FA) - termination of pregnancy for FA and psychological consequences [abstract]. Journal of Obstetrics and Gynaecology 2004;24(Suppl 1):S19.
66. Snaith VJ, Howel D, Chadwick T, Deverill M, Hewison J, Sturgiss SN, et al. First trimester ultrasound screening - the psychological consequences of termination of pregnancy for foetal abnormality. Journal of Reproductive and Infant Psychology 2004;22(3):239.
67. Sturgiss S, Howel D, Snaith V, Deverill M, Hewison J, Robson S. The Newcastle randomized controlled trial of early ultrasound screening for fetal abnormality: impact on gestation at diagnosis [abstract]. Journal of Obstetrics and Gynaecology 2005;25 Suppl 1:S20.
68. McClure EM, Nathan RO, Saleem S, Esamai F, Garces A, Chomba E, et al. First look: a cluster-randomized trial of ultrasound to improve pregnancy outcomes in low income country settings. BMC Pregnancy and Childbirth. NCT01990625 2014; Vol. 14, issue 1:73.
69. Barrett J, Brinson J. Evaluation of obstetric ultrasonography at the first prenatal visit. American Journal of Obstetrics and Gynecology 1991;165:1002-5.
70. Berghella V, Baxter JK, Hendrix NW. Cervical assessment by ultrasound for preventing preterm delivery. Cochrane Database of Systematic Reviews 2013, Issue 1. [DOI: 10.1002/14651858.CD007235.pub3]
71. Bricker L, Garcia J, Henderson J, Mugford M, Neilson J, Roberts T, et al. Ultrasound screening in pregnancy: a systematic review of the clinical effectiveness, cost-effectiveness and women's views. Health Technology Assessment 2000;4:1-193.
72. Bricker L, Neilson JP, Dowswell T. Routine ultrasound in late pregnancy (after 24 weeks' gestation). Cochrane Database of Systematic Reviews 2008, Issue 4. [DOI: 10.1002/14651858.CD001451.pub3]
73. Crane JM, Hutchens D, Crane JMG. Transvaginal sonographic measurement of cervical length to predict preterm birth in asymptomatic women at increased risk: a systematic review. Ultrasound in Obstetrics & Gynecology 2008;31(5):579-87.
74. Dodd JM, Crowther CA. Evidence-based care of women with a multiple pregnancy. Best Practice & Research. Clinical Obstetrics & Gynaecology 2005;19:131-53.
75. Drysdale K, Ridley D, Walker K, Higgins B, Dean T. First-trimester pregnancy scanning as a screening tool for high-risk and abnormal pregnancies in a district general hospital setting. Journal of Obstetrics and Gynaecology 2002;22(2):159-65.
76. European Federation of Societies for Ultrasound in Medicine and Biology. Watchdog Committee, 1994 clinical safety statement. European Journal of Ultrasound 1995;2:77.
77. Garcia J, Bricker L, Henderson J, Martin MA, Mugford M, Neilson J, et al. Women's views of pregnancy ultrasound: a systematic review. Birth 2002;29(4):225-50.
78. Geirsson R, Busby-Earle R. Certain dates may not provide a reliable estimate of gestational age. British Journal of Obstetrics and Gynaecology 1991;98:108-9.
79. McMaster University. GRADEpro. [Computer program on www.gradepro.org]. 2015. McMaster University, 2014.
80. Gulmezoglu AM, Crowther CA, Middleton P, Heatley E. Induction of labour for improving birth outcomes for women at or beyond term. Cochrane Database of Systematic Reviews 2012, Issue 6. [DOI: 10.1002/14651858.CD004945.pub3]
81. Henderson J, Bricker L, Roberts T, Mugford M, Garcia J, Neilson J. British National Health Service's and women's costs of antenatal ultrasound screening and follow-up tests. Ultrasound in Obstetrics & Gynecology 2002;20(2):154-62.
82. 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.
83. Lalor JG, Devane D. Information, knowledge and expectations of the routine ultrasound scan. Midwifery 2007;23(1):13-22.
84. Lee YM, Cleary-Goldman J, Thaker HM, Simpson LL. Antenatal sonographic prediction of twin chorionicity. American Journal of Obstetrics and Gynecology 2006;195:863-7. [MEDLINE: 16949427]
85. LeFevre ML, Bain RP, Ewigman BG, Frigoletto FD, Crane JP, McNellis D, et al. A randomized trial of prenatal ultrasonographic screening: impact on maternal management and outcome. American Journal of Obstetrics and Gynecology 1993;169:483-9.
86. Leivo T, Tuominen R, Saari Kemppainen A, Ylostalo P, Karjalainen O, Heinonen OP. Cost-effectiveness of one-stage ultrasound screening in pregnancy: a report from the Helsinki ultrasound trial. Ultrasound in Obstetrics & Gynecology 1996;7(5):309-14.
87. Neilson JP. High vs low feedback to mother at fetal ultrasound. [revised 12 May 1994]. In: Enkin MW, Keirse MJNC, Neilson JP, Crowther CA (eds) Pregnancy and Childbirth Module. In: The Cochrane Pregnancy and Childbirth Database [database on disk and CDROM] The Cochrane Collaboration; Issue 2, Oxford: Update Software; 1995.
88. Owen J, Wenstrom K. The effect of inaccurate gestational age estimation on the multiple marker screening test (MMST) for fetal Down Syndrome. American Journal of Obstetrics and Gynecology 1997;176:A297.
89. Paneth N. Prenatal sonography - safe or sinister?. Lancet 1998;352:5-6.
90. Peek M, Devonald K, Beilby R, Ellwood D. The value of routine early pregnancy ultrasound in the antenatal booking clinic. Australian and New Zealand Journal of Obstetrics and Gynaecology 1994;34:140-3.
91. Persson PH, Kullander S. Long-term experience of general ultrasound screening in pregnancy. American Journal of Obstetrics and Gynecology 1983;146:942-7.
92. The Nordic Cochrane Centre, The Cochrane Collaboration. Review Manager (RevMan). 5.3. Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, 2014.
93. Roberts T, Henderson J, Mugford M, Bricker L, Neilson J, Garcia J, et al. Antenatal ultrasound screening for fetal abnormalities: a systematic review of studies of cost and cost effectiveness. BJOG: an international journal of obstetrics and gynaecology 2002;109(1):44-56.
94. Rossi AC, Prefumo F. Accuracy of ultrasonography at 11-14 weeks of gestation for detection of fetal structural anomalies: a systematic review. Obstetrics and Gynecology 2013;122(6):1160-7.
95. Saari-Kemppainen A, Karjalainen O, Ylostalo P, Heinonen OP. Ultrasound screening and perinatal mortality: controlled trial of systematic one-stage screening in pregnancy. Lancet 1990;336:387-91.
96. Schunemann HJ. GRADE: from grading the evidence to developing recommendations. A description of the system and a proposal regarding the transferability of the results of clinical research to clinical practice [GRADE: Von der Evidenz zur Empfehlung. Beschreibung des Systems und Losungsbeitrag zur Ubertragbarkeit von Studienergebnissen]. Zeitschrift fur Evidenz, Fortbildung und Qualitat im Gesundheitswesen 2009;103(6):391-400. [PUBMED: 19839216]
97. Whitworth M, Bricker L, Neilson JP, Dowswell T. Ultrasound for fetal assessment in early pregnancy. Cochrane Database of Systematic Reviews 2010, Issue 4. [DOI: 10.1002/14651858.CD007058.pub2]