Table 1.
Variables |
All cases (n = 31 016) |
||||
---|---|---|---|---|---|
# studies |
Total events/participants |
Pooled proportion (%) |
Heterogeneity (I2%) |
||
Age (years) |
Mean age (years) |
40 |
30.92 ± 0.65 |
99.7 |
|
<35 years |
12 |
20 476/25 256 |
54.9 (38.6 to 70.7) |
99.0 |
|
≥35 yearsa |
10 |
4546/24 883 |
31.3 (23.5 to 39.6) |
95.0 |
|
Gestational age (Weeks) |
Mean gestational age |
22 |
33.36 ± 0.71 |
99.6 |
|
First trimester |
9 |
184/1847 |
13.9 (6.4 to 23.3) |
94.5 |
|
Second trimester |
11 |
369/1887 |
20.7 (13.2 to 29.2) |
90.6 |
|
Third trimester |
15 |
1373/2184 |
77.7 (63.4 to 89.5) |
97.5 |
|
≥37 weeks |
4 |
360/1120 |
39.3 (9.3 to 74.5) |
99.0 |
|
<37 weeks |
3 |
602/1056 |
65.1 (22.9 to 96.9) |
99.3 |
|
Parity |
Nulliparous |
18 |
667/1821 |
34.7 (28.4 to 41.3) |
87.4 |
Multiparous |
9 |
464/887 |
51.6 (36.8 to 66.2) |
94.7 |
|
Ethnicity |
White |
8 |
5919/24 962 |
35.2 (16.9 to 55.9) |
99.3 |
Black |
6 |
3586/25 199 |
15.8 (7.4 to 26.5) |
98.5 |
|
Asian |
6 |
1246/24 987 |
61.8 (19.3 to 95.8) |
99.9 |
|
Central/Latin American |
4 |
7230/23 760 |
58.5 (28.1 to 85.7) |
98.8 |
|
Mixed |
2 |
62/488 |
10.6 (8.0 to 13.6) |
98.4 |
|
Others |
4 |
972/24 706 |
2.1 (0.4 to 5.0) |
93.8 |
|
Health insurance |
Private |
4 |
196/436 |
49.4 (39.0 to 59.9) |
75.1 |
Public |
4 |
265/476 |
53.4 (44.2 to 62.5) |
71.9 |
|
Body Mass Index | Mean BMI |
16 |
27.77 ± 0.72 |
99.0 |
|
<25 |
2 |
130/435 |
28.7 (24.2 to 33.3) |
32.4 |
|
25 to <30 |
3 |
480/1166 |
38.2 (28.6 to 48.3) |
89.2 |
|
≥30 | 13 | 735/26 170 | 19.3 (10.5 to 30.0) | 98.8 |