Table 1 Characteristic of children with Down syndrome (DS) and the reference population (REF)

Birth weight (g, mean)

2906.7^a

3409.8

2954.2^a

3428.6

2954.2^a

3389.4

2763.2^a

3396.7

Birth length (cm, mean)

47.4^a

50.2

46.1^a

50.3

47.5^a

50.1

46.9^a

50.1

Gestational age (weeks, mean)^b

36.7^a

39.1

36.7^a

39.2

37.8^a

39.0

37.0^a

39.0

Apgar ≥ 6 after 5 min^b

22 (66.7 %)^a

39694 (99.2 %)

12 (63.1 %)^a

37728 (98.9 %)

20 (76.9 %)^a

36079 (99.0 %)

30 (71.4 %)^a

36859 (99.3 %)

Intervention on delivery

6 (18.2 %)

8913 (19.9 %)

7 (36.8 %)

9224 (21.3 %)

7 (26.9 %)

7213 (17.5 %)

19 (45.2 %)

8845 (21.2 %)

Parity 1

6 (18.2 %)

15002 (33.6 %)

8 (42.1 %)

14776 (34.0 %)

8 (30.8 %)

14083 (34.1 %)

12 (28.6 %)

14359 (34.4 %)

Parity 2

6 (18.2 %)

5643 (12.6 %)

1 (5.3 %)

5289 (12.2 %)

5 (19.2 %)

5015 (12.1 %)

5 (11.9 %)

5116 (12.3 %)

Parity 3

3 (9.1 %)

1597 (3.6 %)

1 (5.3 %)

1525 (3.5 %)

3 (11.6 %)

1469 (3.6 %)

3 (7.1 %)

1483 (3.6 %))

Parity ≥4

3 (9.1 %)

1017 (2.3 %)

0 (0.0 %)

1044 (2.4 %)

1 (3.8 %)

1015 (2.5 %)

1 (2.4 %)

1024 (2.5 %)

Parity 0

15 (45.4 %)

21414 (47.9 %)

9 (47.4 %)

20766 (47.8 %)

9 (34.6 %)

19724 (47.8 %)

21 (50.0 %)

19779 (47.4 %)

Mother age (years, mean)

32.7^a

29.0

31.8^a

28.2

32.0^a

30.0

33.2^a

29.2

Breast feeding

21 (63.6 %)^a

42676 (95.5 %)

11 (57.9 %)^a

40812 (94.0 %)

19 (73.1 %)^a

39413 (95.4 %)

31 (73.80 %)^a

40268 (96.4 %)

Perinatal mortality (on 10000)

5 (1515.2)

343 (76.8)

3 (1578.9)

323 (74.4)

2 (769.2)

268 (64.9)

4 (952.4)

240 (57.5)

Fetal mortality (on 10000)

4 (1212.1)

191 (42.7)

1 (526.3)

210 (48.4)

1 (384.6)

158 (38.3)

3 (714.3)

162 (38.8)

Early neonatal mortality (on 10000 newborns)

1 (344.8)

152 (34.2)

2 (1111.1)

111 (25.7)

1 (400.0)

102 (24.8)

1 (256.4)

77 (18.5)