J. L. Goujard and . Trisome, Approche épidémiologique INSERM U 149, 1997.

E. Flori, B. Doray, and N. Carelle, Trisomie 21: de la conception à la naissance, Faculté de Médecine de Strasbourg, Février, 2007.

E. Bornstein, E. Lenchner, A. Donnenfeld, C. Jodicke, S. Keeler et al., Complete trisomy 21 vs translocation Down syndrome: a comparison of modes of ascertainment, American Journal of Obstetrics and Gynecology, vol.203, issue.4, pp.391-392, 2010.
DOI : 10.1016/j.ajog.2010.06.019

A. Mégarbané, A. Ravel, C. Mircher, F. Sturtz, Y. Grattau et al., The 50th anniversary of the discovery of trisomy 21: The past, present, and future of research and treatment of Down syndrome, Genetics in Medicine, vol.4, issue.9, pp.611-617, 2009.
DOI : 10.1097/GIM.0b013e3181b2e34c

M. Gautier, Fiftieth anniversary of trisomy 21: returning to a discovery, Human Genetics, vol.42, issue.7, pp.311-316, 2009.
DOI : 10.1007/s00439-009-0690-1

G. Neri and J. Opitz, Down syndrome: Comments and reflections on the 50th anniversary of Lejeune's discovery, American Journal of Medical Genetics Part A, vol.22, issue.12, pp.2647-54, 2009.
DOI : 10.1002/ajmg.a.33138

A. Toth and J. Szabo, Ethical aspects of prenatal screening for Down's syndrome. Orv Hetil, oct, vol.15141, issue.42, pp.2293-2301, 2000.

M. Flori and J. Gofette, Réflexions éthiques sur le dépistage de risque de la trisomie 21 par les marqueurs sériques. Exercer, Novembre/Décembre, issue.75, pp.126-129, 2005.

F. Muller, S. Dreux, J. Oury, D. Luton, S. Uzan et al., Down syndrome maternal serum marker screening after 18 weeks' gestation. Prenatal Diagnosis, pp.1001-1005, 2002.
DOI : 10.1002/pd.451

M. Bogart, M. Pandian, and O. Jones, Abnormal maternal serum chorionic gonadotropin levels in pregnancies with fetal chromosome abnormalities, Prenatal Diagnosis, vol.98, issue.9, pp.623-653, 1987.
DOI : 10.1002/pd.1970070904

M. Bogart, M. Golbus, N. Sorg, and O. Jones, Human chorionic gonadotropin levels in pregnancies with aneuploid fetuses, Prenatal Diagnosis, vol.297, issue.6, pp.379-84, 1989.
DOI : 10.1002/pd.1970090602

I. Merkatz, K. Martin, and J. Beal, Gastric secretion during pregnancy and lactation: Clinical and experimental studies, Obstet Gynecol, vol.24, pp.587-93, 1964.

S. Stone, R. Henley, T. Reynolds, and R. John, A comparison of total and free ??HCG assays in Down syndrome screening. Prenatal Diagnosis, pp.535-542, 1993.

N. Wald, H. Cuckle, and P. Royston, ANTENATAL SCREENING FOR DOWN SYNDROME, The Lancet, vol.332, issue.8624, p.1362, 1988.
DOI : 10.1016/S0140-6736(88)90891-4

J. Macri, R. Kasturi, D. Krantz, E. Cook, N. Moore et al., Maternal serum Down syndrome screening: Free ??-protein is a more effective marker than human chorionic gonadotropin, American Journal of Obstetrics and Gynecology, vol.163, issue.4, pp.1248-53, 1990.
DOI : 10.1016/0002-9378(90)90700-H

J. Canick, G. Knight, G. Palomaki, J. Haddow, H. Cuckle et al., Low second trimester maternal serum unconjugated oestriol in pregnancies with Down's syndrome, BJOG: An International Journal of Obstetrics and Gynaecology, vol.95, issue.4, pp.330-333, 1988.
DOI : 10.1016/S0140-6736(85)91071-2

N. Wald, H. Cuckle, J. Densem, K. Nanchahal, J. Canick et al., Maternal serum unconjugated oestriol as an antenatal screening test for Down's syndrome, BJOG: An International Journal of Obstetrics and Gynaecology, vol.26, issue.4, pp.334-375, 1988.
DOI : 10.1016/S0140-6736(84)92389-4

T. Faraut, C. Cans, M. Althuser, and P. S. Jouk, Utilisation conjointe de la clarté nucale, de l'âge gestationnel et de l'âge maternel pour l'estimation du risque de trisomie 21, J GynecolObstetBiolReprod, vol.28, pp.439-445, 1999.

Y. Liu, L. Li, and Y. Wu, Analysis of Down syndrome screening by maternal serum detection in mid-pregnancy. Nan Fang Yi Ke Da XueXueBao, pp.532-536, 2010.

K. Nicolaides, Nuchal translucency and other first-trimester sonographic markers of chromosomal abnormalities, American Journal of Obstetrics and Gynecology, vol.191, issue.1, pp.45-67, 2004.
DOI : 10.1016/j.ajog.2004.03.090

H. Jou, J. Shih, S. Wu, T. Li, C. Tzeng et al., First-trimester Down's syndrome screening by fetal nuchal translucency measurement in Taiwan, J. Formos. Med. Assoc, vol.100, issue.4, pp.257-61, 2001.

G. Susanne, S. Sissel, U. W. , C. G. Sonja, and O. , Pregnant women's responses to information about an increased risk of carrying a baby with Down syndrome, Birth, vol.33, issue.1, pp.64-73, 2006.

V. Seror and Y. Ville, Women's attitudes to the successive decisions possibly involved in prenatal screening for Down syndrome: how consistent with their actual decisions?, Prenatal Diagnosis, vol.20, issue.33, pp.1086-93, 2010.
DOI : 10.1002/pd.2616

V. Seror and Y. Ville, Prenatal screening for Down syndrome: women's involvement in decision-making and their attitudes to screening, Prenatal Diagnosis, vol.27, issue.6, pp.120-128, 2009.
DOI : 10.1002/pd.2183

K. Tyzack and E. Wallace, Down syndrome screening: what do health professionals know? Aust N Z J ObstetGynaecol, pp.217-238, 2003.
DOI : 10.1046/j.0004-8666.2003.00070.x

M. Ekelin and E. Crang-svalenius, Midwives' attitudes to and knowledge about a newly introduced foetal screening method, Scandinavian Journal of Caring Sciences, vol.1, issue.3, pp.287-93, 2004.
DOI : 10.1054/midw.2000.0243

URL : http://lup.lub.lu.se/record/127521/file/624087.pdf

M. Koster, E. Wortelboer, P. Stoutenbeek, G. Visser, and P. Schielen, Modeling Down syndrome screening performance using first-trimester serum markers. UltrasoundObstetGynecol, pp.134-143, 2011.

Y. Ville, How to improve the screening and diagnosis of fetal aneuploidy?, Bull. Acad. Natl. Med, vol.189, issue.8, pp.1773-1784, 2005.

C. Vestergaard, Ø. Lidegaard, and A. Tabor, Invasive prenatal diagnostic practice in Denmark 1996 to 2006, Acta Obstetricia et Gynecologica Scandinavica, vol.88, issue.3, pp.362-367, 1996.
DOI : 10.1080/00016340902730367

H. Madsen, S. Ball, D. Wright, N. Tørring, O. Petersen et al., A reassessment of biochemical marker distributions in trisomy 21-affected and unaffected twin pregnancies in the first trimester, Ultrasound in Obstetrics & Gynecology, vol.25, issue.1, pp.38-47, 2011.
DOI : 10.1002/uog.8845

A. Garchet-beaudron, S. Dreux, N. Leporrier, J. Oury, and F. Muller, Second-trimester Down syndrome maternal serum marker screening: a prospective study of 11 040 twin pregnancies, Prenatal Diagnosis, vol.98, issue.12, pp.1105-1114, 2008.
DOI : 10.1002/pd.2145

A. Cahill, G. Macones, D. Stamilio, J. Dicke, J. Crane et al., Pregnancy loss rate after mid-trimester amniocentesis in twin pregnancies, American Journal of Obstetrics and Gynecology, vol.200, issue.3, pp.257-258, 2009.
DOI : 10.1016/j.ajog.2008.09.872

G. Simonazzi, A. Curti, A. Farina, G. Pilu, L. Bovicelli et al., Amniocentesis and chorionic villus sampling in twin gestations: which is the best sampling technique? American Journal of Obstetrics and Gynecology, pp.365-366, 2010.

R. Bahado-singh, A. Oz, K. Gomez, D. Hunter, J. Copel et al., Combined ultrasound biometry, serum markers and age for Down syndrome risk estimation, Ultrasound in Obstetrics and Gynecology, vol.175, issue.3, pp.199-204, 2000.
DOI : 10.1002/(SICI)1097-0223(199904)19:4<351::AID-PD546>3.3.CO;2-O

P. Rozenberg, L. Bussières, and M. Senat, Down syndrome screening in France: the worst consensus, J GynecolObstetBiolReprod, vol.36, issue.2, pp.95-103, 2007.

J. Egan, P. Benn, A. Borgida, J. Rodis, W. Campbell et al., Efficacy of screening for fetal Down syndrome in the United States from 1974 to 1997, Obstet Gynecol, vol.96, issue.6, pp.979-85, 2000.

F. Audibert, M. Dommergues, C. Benattar, J. Taieb, J. Thalabard et al., Screening for Down syndrome using first-trimester ultrasound and second-trimester maternal serum markers in a low-risk population: a prospective longitudinal study, Ultrasound in Obstetrics and Gynecology, vol.179, issue.1, pp.26-31, 2001.
DOI : 10.1046/j.1469-0705.1999.13030167.x

P. Rozenberg, L. Malagrida, H. Cuckle, I. Durand-zaleski, I. Nisand et al., Down's syndrome screening with nuchal translucency at 12+0-14+0 weeks and maternal serum markers at 14+1-17+0 weeks: a prospective study, Human Reproduction, vol.17, issue.4, pp.1093-1101, 2002.
DOI : 10.1093/humrep/17.4.1093

URL : http://humrep.oxfordjournals.org/cgi/content/short/17/4/1093

C. De-vigan, B. Khoshnood, E. Cadio, V. Vodovar, and F. Goffinet, Prenatal diagnosis and prevalence of Down syndrome in the Parisian population, pp.146-50, 2001.

C. Hörmansdörfer, M. Golatta, A. Scharf, P. Hillemanns, and P. Schmidt, Age-independent first trimester screening for Down syndrome: analysis of three modified software programs with 6,508 pregnancies, Archives of Gynecology and Obstetrics, vol.19, issue.9, pp.749-54, 2011.
DOI : 10.1007/s00404-010-1452-y

S. Wasden, B. Adams, and S. Chasen, Are age cutoffs still used to identify candidates for invasive testing for chromosomal abnormalities?, J Reprod Med, vol.56, pp.3-4113, 2011.
DOI : 10.1016/j.ajog.2009.10.729

P. Muller, R. Cocciolone, E. Haan, C. Wilkinson, H. Scott et al., Trends in state/population-based Down syndrome screening and invasive prenatal testing with the introduction of first-trimester combined Down syndrome screening, South Australia, Am. J. Obstet. Gynecol, vol.196, issue.4, pp.315-316, 1995.

V. Davies, J. Gledhill, A. Mcfadyen, B. Whitlow, and D. Economides, Psychological outcome in women undergoing termination of pregnancy for ultrasound-detected fetal anomaly in the first and second trimesters: a pilot study, Ultrasound in Obstetrics and Gynecology, vol.1, issue.4, pp.389-92, 2005.
DOI : 10.1002/uog.1854

F. Muller, D. Thibaud, F. Poloce, M. Gelineau, M. Bernard et al., Risk of amniocentesis in women screened positive for Down syndrome with second trimester maternal serum markers, Prenatal Diagnosis, vol.297, issue.11, pp.1036-1045, 2002.
DOI : 10.1002/pd.449

P. Gaudry, G. Grangé, A. Lebbar, A. Choiset, S. Girard et al., Fetal Loss after Amniocentesis in a Series of 5,780 Procedures, Fetal Diagnosis and Therapy, vol.23, issue.3, pp.217-238, 2008.
DOI : 10.1159/000116744

M. Dufeu and . Thèse-pour-le-doctorat-en-médecine, Dépistage de la trisomie 21 par le test combiné du premier trimestre : enjeux et bénéfices, 2011.

L. Learman, E. Drey, E. Gates, M. Kang, A. Washington et al., Abortion attitudes of pregnant women in prenatal care, American Journal of Obstetrics and Gynecology, vol.192, issue.6, pp.1939-1945, 2005.
DOI : 10.1016/j.ajog.2005.02.042

M. Korenromp, G. Christiaens, J. Van-den-bout, E. Mulder, J. Hunfeld et al., Long-term psychological consequences of pregnancy termination for fetal abnormality: a cross-sectional study, Prenatal Diagnosis, vol.22, issue.3, pp.253-60, 2005.
DOI : 10.1002/pd.1127