Skip to main content

Table 3 Chromosome abnormalities by maternal age, risk of trisomy 21 (T21), nuchal translucency (NT), pregnancy associated plasma protein A (PAPP-A) and free β-human chorionic gonadotropin (fβ-hCG)

From: Factors associated with common and atypical chromosome abnormalities after positive combined first-trimester screening in Chinese women: a retrospective cohort study

 

Total pregnancies

Total abnormalities

T21,18 or 13 or SCA

Atypical abnormalities

p

High risk for T21 ≥ 1 in 250

1799

99

79 (4.4%)

20 (1.1%)

< 0.001*

High risk for 18 ≥ 1 in 180

5

4

3 (60.0%)

0 (0%)

 

High risk for T21 and 18

51

34

33 (64.7%)

2 (3.9%)

Risk of T21 > 1 in 100

793

111

97 (12.2%)

13 (1.6%)

< 0.001*

Risk of T21 < 1 in 100

1062

26

18 (1.7%)

9 (0.8%)

Age ≥ 45

20

2

2 (10.0%)

0 (0%)

0.899

Age ≥ 35 < 45

1190

87

74 (6.2%)

14 (1.2%)

 

Age < 35

645

48

39 (6.0%)

8 (1.2%)

NT (mm) median (range)

1855

137

3.8 (1.1–12.2)

2.4 (1.4–12.6)

NT MoM

1855

137

2.26 (0.68–7.19)

1.31 (0.82–7.15)

NT ≥ 3.5 mm

216

65

55 (25.5%)

9 (4.2%)

< 0.001*

NT < 3.5 mm

1639

72

60 (3.7%)

13 (0.8%)

PAPP-A MoM

1855

137

0.32 (0.05–2.32)

0.39 (0.09–1.64)

 

Low PAPP-A

68

27

23 (33.8%)

5 (7.4%)

< 0.001*

Normal PAPP-A

1787

110

92 (5.1%)

17 (1.0%)

fβ-hCG MOM

1855

137

1.44 (0.03–9.75)

1.60 (0.24–4.07)

 

Low or high fβ-hCG

98

7

7 (7.1%)

0 (0%)

0.503

Normal fβ-hCG

1757

130

108 (6.1%)

22 (1.3%)

  1. T trisomy, SCA sex chromosome aneuploidies, Atypical abnormalities abnormalities other than trisomies 21, 18, and 13 and sex chromosome abnormalities, MoM multiple of medians, low < 0.2, high ≥5.0 MoM. N (%), median (range), as appropriate.
  2. Chi-square test, *p < 0.05: significant