Decision Making and Attitudes towards Invasive Prenatal Diagnosis in the Early Second Trimester

Zusammenfassung

Ziel: Untersuchung des Einflusses von vorbestehender Einstellung, ergebnisoffener Beratung sowie detaillierter Ultraschalldiagnostik auf die Entscheidung bezüglich einer invasiven Pränataldiagnostik im zweiten Trimenon. Material und Methoden: Eine prospektive Studie an einem Stufe-III-Zentrum von 2005 – 2007 unter Einschluss von 696 Hochrisiko-Schwangeren in der 15.–18. Schwangerschaftswoche. Die Einstellung der Schwangeren im Hinblick auf eine invasive Pränataldiagnostik wurde vor und nach genetischer Beratung sowie gezielter Ultraschalldiagnostik evaluiert. Ergebnisse: Zum Zeitpunkt der initialen Beratung waren 311 (44,7 %) Frauen a priori für eine invasive Diagnostik (Gruppe 1), 150 (21,5 %) dagegen (Gruppe 2) und 235 (33,8 %) wollten ihre Entscheidung in Abgängigkeit des Ultraschallbefunds treffen (Gruppe 3). Für eine Amniozentese entschieden sich 87,1 % in Gruppe 1, 5,3 % in Gruppe 2 und 13,6 % in Gruppe 3. Insgesamt wurde die A-priori-Einstellung nur wenig durch die Ultraschalluntersuchung beeinflusst. Lediglich 12,9 % der initial für eine Amniozentese und 5,3 % der initial ablehnend gegenüber einer Amniozentese eingestellten Schwangeren änderten ihre Einstellung. Im Gegensatz dazu entschieden sich in Gruppe 3 nach unauffälligem Ultraschall 86,7 % der Schwangeren gegen eine invasive Diagnostik. Schlussfolgerung: Die bereits bestehende Einstellung oder im Vorfeld gebildete Meinung der Schwangeren sind die stärksten Faktoren, die sich auf die Entscheidung für oder gegen eine Amniozentese auswirken, während die Ultraschalluntersuchung nur einen unwesentlichen Einfluss hat. Bei Schwangeren, die eine gezielte Ultraschalldiagnostik bewusst als Entscheidungshilfe in Anspruch nehmen, besitzt sie jedoch einen hohen Stellenwert.

Abstract

Purpose: To investigate the impact of the a priori attitude, nondirective counselling and targeted second trimester ultrasound examination on the decision process concerning invasive prenatal diagnosis in the second trimester. Material and Methods: A prospective study including 696 high-risk pregnancies at 15 to 18 weeks’ gestation, performed from 2005 – 2007. Attitudes towards invasive prenatal testing were explored before and after genetic counselling and targeted ultrasound examination in a tertiary referral centre. Results: Initially, 311 (44.7 %) women intended to have an invasive testing (group 1), 150 women (21.5 %) were against an invasive procedure (group 2), and 235 women (33.8 %) wanted to make their final decision depending on the sonographic result (group 3). The total rate of amniocentesis was 87.1 %, 5.3 % and 13.6 %, respectively. Overall, the a priori decision was sparsely influenced by the ultrasound examination. Only 12.9 % (40 / 311) and 5.3 % (8 / 150) of the primarily determined women (group 1, 2) changed their opinion. However, in the initially undecided group, 86.7 % declined an amniocentesis after a normal ultrasound scan. Conclusion: The referral indication and the a priori opinion are the strongest influencing factors with regard to invasive testing and the ultrasound scan has a low impact in those preselected patients. However, ultrasound has an important reassuring aspect in women willing to use ultrasound as assistance in the process of decision making.

Key words

down syndrome - fetus - screening - invasive testing - amniocentesis

References

• 1 Shohat M, Akstein E, Davidov B. et al . Amniocentesis rate and the detection of Down syndrome and other chromosomal anomalies in Israel.  Prenat Diagn. 1995;  15 967-970
• 2 Pandya P P, Snijders R J, Johnson S P. et al . Screening for fetal trisomies by maternal age and fetal nuchal translucency thickness at 10 to 14 weeks of gestation.  Br J Obstet Gynaecol. 1995;  102 957-962
• 3 Yagel S, Anteby E Y, Hochner-Celnikier D. et al . The role of midtrimester targeted fetal organ screening combined with the ”triple test” and maternal age in the diagnosis of trisomy 21: a retrospective study.  Am J Obstet Gynecol. 1998;  178 40-44
• 4 Wellesley D, Boyle T, Barber J. et al . Retrospective audit of different antenatal screening policies for Down’s syndrome in eight district general hospitals in one health region.  BMJ. 2002;  325 15
• 5 Leschot N J, Vejerslev L O. Proceedings of the EUROCROMIC. Workshop on Prenatal Diagnosis.  Eur J Hum Genet. 1997;  5 1-6
• 6 Clerici G, Donti E, Zacutti A. et al . Prenatal diagnosis in Italy.  Eur J Hum Genet. 1997;  5 42-47
• 7 Vintzileos A M, Guzman E R, Smulian J C. et al . Choice of second-trimester genetic sonogram for detection of trisomy 21.  Obstet Gynecol. 1997;  90 187-190
• 8 Kagan K O, Wright D, Baker A. et al . Screening for trisomy 21 by maternal age, fetal nuchal translucency thickness, free beta-human chorionic gonadotropin and pregnancy-associated plasma protein-A.  Ultrasound Obstet Gynecol. 2008;  31 618-624
• 9 Merz E, Thode C, Alkier A. et al . A new approach to calculating the risk of chromosomal abnormalities with first-trimester screening data.  Ultraschall in Med. 2008;  29 639-645
• 10 Mujezinovic F, Alfirevic Z. Procedure-related complications of amniocentesis and chorionic villous sampling: a systematic review.  Obstet Gynecol. 2007;  110 687-694
• 11 Kozlowski P, Knippel A, Stressig R. Individual risk of fetal loss following routine second trimester amniocentesis: a controlled study of 20,460 cases.  Ultraschall in Med. 2008;  29 165-172
• 12 Geipel A, Gembruch U, Ludwig M. et al . Genetic sonography as the preferred option of prenatal diagnosis in patients with pregnancies following intracytoplasmic sperm injection.  Hum Reprod. 1999;  14 2629-2634
• 13 Nicolaides K H. Screening for chromosomal defects.  Ultrasound Obstet Gynecol. 2003;  21 313-321
• 14 Bromley B, Lieberman E, Benacerraf B R. The incorporation of maternal age into the sonographic scoring index for the detection at 14 – 20 weeks of fetuses with Down’s syndrome.  Ultrasound Obstet Gynecol. 1997;  10 321-324
• 15 Salihu H M, Boos R, Schmidt W. Antenatally detectable markers for the diagnosis of autosomally trisomic fetuses in at-risk pregnancies.  Am J Perinatol. 1997;  14 257-261
• 16 DeVore G R. The genetic sonogram: its use in the detection of chromosomal abnormalities in fetuses of women of advanced maternal age.  Prenat Diagn. 2001;  21 40-45
• 17 Shipp T D, Benacerraf B R. Second trimester ultrasound screening for chromosomal abnormalities.  Prenat Diagn. 2002;  22 296-307
• 18 Nyberg D A, Luthy D A, Resta R G. et al . Age-adjusted ultrasound risk assessment for fetal Down’s syndrome during the second trimester: description of the method and analysis of 142 cases.  Ultrasound Obstet Gynecol. 1998;  12 8-14
• 19 Benacerraf B R. The role of the second trimester genetic sonogram in screening for fetal Down syndrome.  Semin Perinatol. 2005;  29 386-394
• 20 Priest J H, FitzGerald J M, Haag M M. et al . Acceptance of amniocentesis by women in the state of Montana (USA) who are screen positive for Down’s syndrome.  J Med Screen. 1998;  5 178-182
• 21 Santalahti P, Aro A R, Hemminki E. et al . On what grounds do women participate in prenatal screening?.  Prenat Diagn. 1998;  18 153-165
• 22 Berg van den M, Timmermans D R, Kleinveld J H. et al . Accepting or declining the offer of prenatal screening for congenital defects: test uptake and women’s reasons.  Prenat Diagn. 2005;  25 84-90
• 23 Cicero S, Sonek J D, McKenna D S. et al . Nasal bone hypoplasia in trisomy 21 at 15 – 22 weeks’ gestation.  Ultrasound Obstet Gynecol. 2003;  21 15-18
• 24 Odibo A O, Sehdev H M, Stamilio D M. et al . Defining nasal bone hypoplasia in second-trimester Down syndrome screening: does the use of multiples of the median improve screening efficacy?.  Am J Obstet Gynecol. 2007;  197 361.e1-361.4
• 25 Gray D L, Crane J P. Optimal nuchal skin-fold thresholds based on gestational age for prenatal detection of Down syndrome.  Am J Obstet Gynecol. 1994;  171 1282-1286
• 26 DeVore G R. The role of fetal echocardiography in genetic sonography.  Semin Perinatol. 2003;  27 160-172
• 27 Cho R C, Chu P, Smith-Bindman R. Second trimester prenatal ultrasound for the detection of pregnancies at increased risk of Trisomy 18 based on serum screening.  Prenat Diagn. 2009;  29 129-139
• 28 Breathnach F M, Fleming A, Malone F D. The second trimester genetic sonogram.  Am J Med Genet C Semin Med Genet. 2007;  145C 62-72
• 29 Maiz N, Valencia C, Kagan K O. et al . Ductus venosus Doppler in screening for trisomies 21, 18 and 13 and Turner syndrome at 11 – 13 weeks of gestation.  Ultrasound Obstet Gynecol. 2009;  33 512-517
• 30 Yeo L, Vintzileos A M. The use of genetic sonography to reduce the need for amniocentesis in women at high-risk for Down syndrome.  Semin Perinatol. 2003;  27 152-159
• 31 Vergani P, Locatelli A, Biffi A. et al . Factors affecting the decision regarding amniocentesis in women at genetic risk because of age 35 years or older.  Prenat Diagn. 2002;  22 769-774
• 32 Rosen D J, Kedar I, Amiel A. et al . A negative second trimester triple test and absence of specific ultrasonographic markers may decrease the need for genetic amniocentesis in advanced maternal age by 60 %.  Prenat Diagn. 2002;  22 59-63
• 33 Vintzileos A M, Guzman E R, Smulian J C. et al . Down syndrome risk estimation after normal genetic sonography.  Am J Obstet Gynecol. 2002;  187 1226-1229
• 34 Bahado-Singh R, Deren O, Oz U. et al . An alternative for women initially declining genetic amniocentesis: individual Down syndrome odds on the basis of maternal age and multiple ultrasonographic markers.  Am J Obstet Gynecol. 1998;  179 514-519
• 35 Sharda S, Phadke S R. Uptake of invasive prenatal diagnostic tests in women after detection of soft markers for chromosomal abnormality on ultrasonographic evaluation.  J Perinatol. 2007;  27 550-555
• 36 Geipel A, Daiss T, Katalinic A. et al . Changing attitudes towards non-invasive aneuploidy screening at advanced maternal age in a German tertiary care center.  Ultraschall in Med. 2007;  28 67-70
• 37 Zoppi M A, Ibba R M, Putzolu M. et al . Nuchal translucency and the acceptance of invasive prenatal chromosomal diagnosis in women aged 35 and older.  Obstet Gynecol. 2001;  97 916-920
• 38 Caughey A B, Musci T J, Belluomini J. et al . Nuchal translucency screening: how do women actually utilize the results?.  Prenat Diagn. 2007;  27 119-123
• 39 Chasen S T, McCullough L B, Chervenak F A. Is nuchal translucency screening associated with different rates of invasive testing in an older obstetric population?.  Am J Obstet Gynecol. 2004;  190 769-774
• 40 Nadel A S, Bromley B, Frigoletto F DJ. et al . Can the presumed risk of autosomal trisomy be decreased in fetuses of older women following a normal sonogram?.  J Ultrasound Med. 1995;  14 297-302