Appendix Table 1: Number of amniocentesis recorded from Wessex Regional Genetics Laboratory between 1971 and 1988 and the estimated proportion of Down’s syndrome pregnancies to women over 35 being prenatally diagnosed and subsequently terminated

Year of sample / Number of Amnio -centesis
(a) / Estimated proportion of women 35 and older with a Down’s syndrome pregnancy having a termination [a/2117*60] (%) † / Down’s syndrome live births
Estimated in absence of screening and subsequenttermination / Estimated after subsequent termination in women 35 and older
1971 / 5 / 0 / 1115 / 1112
1972 / 31 / 1 / 1009 / 1003
1973 / 59 / 2 / 910 / 902
1974 / 125 / 4 / 841 / 827
1975 / 344 / 10 / 789 / 759
1976 / 442 / 13 / 754 / 718
1977 / 706 / 20 / 738 / 686
1978 / 1037 / 29 / 815 / 733
1979 / 1093 / 31 / 847 / 753
1980 / 1162 / 33 / 879 / 773
1981 / 1370 / 39 / 865 / 737
1982 / 1526 / 43 / 870 / 721
1983 / 1649 / 47 / 890 / 721
1984 / 1832 / 52 / 909 / 714
1985 / 1888 / 54 / 940 / 732
1986 / 1941 / 55 / 952 / 735
1987 / 2104 / 60 / 998 / 747
1988 / 2117 / 60 / 1022 / 762

†: In 1988 60% of women over 35 with a Down’s syndrome diagnosis had had prenatal diagnosis and a subsequent termination.1 If 2117 amniocentesis corresponds to 60%, then the ratio of the number of amniocentesis on one year / 2117 * 60% estimates the proportion of Down’s syndrome pregnancies to women over 35 being prenatally diagnosed and subsequently terminated.

Appendix Table 2: Published studies of 1-, 5-, and 10-year survival rates of children with Down’s syndrome

Survival Rates
Study / Country / Period / n / 1 Year / 5 Year / 10 Year
Oster in Carter (1958)2 / Denmark / 1923-1949 / 72 / 47.00
Record & Smith in Maaskant (1993)3 / GB / 1942-1952 / 252 / 49.90 / 44.10
Carter (1958)2 / GB / 1944-1955 / 698 / 46.90 / 39.60 / 36.80
Collman&Stoller (1963a,b)4, 5 / Australia / 1948-1957 / 729 / 68.90 / 49.40 / 46.20
Lane & Stratford (1988)6 / GB / 1948-1958 / NA / 38.00 / 30.00
Fabia&Drolette in Maaskant (1993)3 / USA / 1950-1966 / 2421 / 76.80 / 68.50 / 64.50
Gallagher & Lowry in Fryers (1986)7 / Canada / 1952-1971 / 927 / 89.40 / 84.90 / 82.10
Baird &Sadovnick (1987)8 / Canada / 1952-1981 / 1341 / 82.79 / 79.05 / 76.66
Lunn in Maaskant (1993)3 / GB / 1953-1958 / 117 / 76.10
Elwood &Darragh in Maaskant (1993)3 / N Ireland / 1960-1969 / 101 / 64.40 / 60.23 / 58.74
Fryers & MacKay (1979)9 / GB / 1961-1977 / 50 / 83.30 / 68.80
Fryers (1986)7 / GB / 1961-1980 / 59 / 81.40 / 77.20 / 70.70
Glasson et al. (2002)10 / Australia / 1961-1970 / 154 / 94.00 / 86.70 / 84.00
Masaki et al. (1981)11 / Japan / 1966-1975 / 1052 / 93.60 / 87.10 / 86.00
Mulcahy in Fryers (1986)7 / Australia / 1966-1976 / 231 / 83.50
Glasson et al. (2002)10 / Australia / 1971-1980 / 186 / 94.00 / 90.70 / 89.00
Frid et al. (1999)12 / Sweden / 1973-1980 / 224 / 85.40 / 76.50
Bell, Pearn&Firman in Maaskant (1993)3 / Australia / 1976-1985 / 366 / 87.20
Dupont, Vaeth&Videbech (1986)13 / Denmark / 1976-1984 / 2412 / 91.97 / 83.99 / 82.40
Malone(1988)14 / Australia / 1976-1984 / 149 / 93.90
McGrother& Marshall in Maaskant (1993)3 / GB / 1976-1985 / 107 / 79.00 / 76.70
Mastroiacova, Bertollini&Corchia (1992)15 / Italy / 1978-1984 / 917 / 79.80 / 76.40
Maaskant (1993)3 / Netherland / 1979-1983 / NA / 89.60 / 88.25
Rasmussen et al. (2006)16 / USA / 1979-1998 / 645 / 92.90 / 90.00 / 88.60
Dastgiri, Gilmour & Stone (2003)17 / GB / 1980-1997 / 210 / 87.14 / 84.29 / 82.21
Hayes et al. (1997)18 / N Ireland / 1980-1989 / 389 / 88.00 / 83.50 / 83.00
Leonard et al. (2000)19 / Australia / 1980-1985 / 139 / 89.00 / 80.00 / 79.00
Mikkelsen, Poulsen& Nielsen (1990)20 / Denmark / 1980-1985 / 278 / 85.40
De Walle et al. (1995)21 / Netherland / 1981-1991 / 119 / 83.00 / 79.50 / 75.00
Glasson et al. (2002)10 / Australia / 1981-1990 / 236 / 94.00 / 91.90 / 89.00
Wang et al. (2011)22 / USA / 1983-2006 / 6819 / 91.95 / 89.88 / 89.00
Bell et al. (2003)23 / GB / 1985-1989 / 306 / 84.64
Irving et al. (2008)24 / GB / 1985-1994 / 374 / 87.00
Tennant et al. (2010)25 / GB / 1985-2003 / 1336 / 88.40 / 84.60 / 83.90
Forrester &Merz (2003)26 / USA / 1986-1999 / 231 / 92.00
Leonard et al. (2000)19 / Australia / 1986-1990 / 133 / 92.00 / 86.00 / 85.00
Bell et al. (2003)23 / GB / 1990-1994 / 256 / 83.20
Goldman et al. (2011)27 / USA / 1990-2006 / 1305 / 92.60
CCASN*28 / Canada / 1991-1999 / 4046 / 95.20
Glasson et al. (2002)10 / Australia / 1991-2000 / 254 / 97.80 / 97.30 / 95.00
Leonard et al. (2000)19 / Australia / 1991-1996 / 165 / 94.00 / 93.00
Bell et al. (2003)23 / GB / 1995-1999 / 241 / 88.80
Frid (2002)29 / Sweden / 1995-1998 / 90 / 97.50
Irving et al. (2008)24 / GB / 1995-2004 / 374 / 94.00
Nembhard et al. (2001)30 / USA / 1995-1997 / 456 / 92.30
CBS-table primary cause of death31 / Netherland / 1996-2005 / NA / 96.00
Vendola et al. (2010)32 / USA / 1999-2003 / 2041 / 95.00
Weijerman et al. (2008)33 / Netherland / 2003-2004 / 182 / 96.00

*Canadian Congenital Anomalies Surveillance NetworkNA: data not given in the paper
Appendix Table 3:Live births with Down’s syndrome between 1971 and 2008 reported by National Congenital Anomaly Statistics and National Down Syndrome Register34

Year / Live births with Down’s syndrome from NCAS / Live birth with Down’s syndrome from NDSCR since 1989
1971 / 582
1972 / 560
1973 / 523
1974 / 419
1975 / 454
1976 / 399
1977 / 425
1978 / 444
1979 / 463
1980 / 481
1981 / 475
1982 / 527
1983 / 497
1984 / 505
1985 / 442
1986 / 445
1987 / 459
1988 / 428
1989 / 487 / 750
1990 / 415 / 739
1991 / 440 / 737
1992 / 394 / 663
1993 / 311 / 621
1994 / 314 / 640
1995 / 315 / 581
1996 / 319 / 607
1997 / 282 / 667
1998 / 373 / 633
1999 / 337 / 604
2000 / 393 / 596
2001 / 360 / 576
2002 / 355 / 591
2003 / 374 / 620
2004 / 456 / 664
2005 / 453 / 741
2006 / 309 / 760
2007 / 300 / 713
2008 / 364 / 742

Appendix Table 4:Age distribution of people in 2011 with Down’s syndrome in England and Wales.

Age band / Number of people with Down’s syndrome
0 –4 / 3314
5 – 9 / 2816
10 – 14 / 2704
15 – 19 / 2765
20 – 24 / 3099
25 – 29 / 2905
30 – 34 / 2827
35 – 39 / 3356
40 – 44 / 4254
45 – 49 / 4293
50 – 54 / 3016
55 – 59 / 1876
60 – 64 / 1089
65 – 69 / 464
70 – 74 / 101

Figure 1Published studies on survival rates between age 1 and 5 for babies with Down’s syndrome according to year of birth with 95% confidence intervals and fitted regression curve

Figure 2Published studies on survival rates between age 5 and 10 for babies with Down’s syndrome according to year of birth with 95% confidence intervals and fitted regression curve

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