|
|
n |
(%) |
n |
RR |
(95%CI) |
Year of delivery |
2005–2008 |
12 226 |
(3.6) |
335 805 |
1.0 |
Reference |
|
2009–2012 |
12 370 |
(3.5) |
357 174 |
0.95 |
0.93–0.98 |
|
2013–2016 |
9987 |
(3.4) |
296 009 |
0.93 |
0.90–0.95 |
Maternal age (years) |
<20 |
349 |
(2.3) |
15 423 |
0.59 |
0.53–0.66 |
|
20–24 |
3959 |
(3.0) |
133 787 |
0.77 |
0.74–0.80 |
|
24–29 |
11 522 |
(3.8) |
300 127 |
1.0 |
Reference |
|
30–34 |
13 037 |
(3.8) |
341 750 |
0.99 |
0.97–1.02 |
|
34–39 |
4919 |
(3.0) |
165 330 |
0.78 |
0.75–0.80 |
|
≥40 |
797 |
(2.4) |
32 571 |
0.64 |
0.59–0.68 |
Parity |
1 |
25 576 |
(6.0) |
429 727 |
2.81 |
2.74–2.88 |
|
2 |
7871 |
(2.1) |
371 933 |
1.0 |
Reference |
|
≥3 |
1136 |
(0.6) |
187 338 |
0.29 |
0.27–0.31 |
Smoking |
Yes |
1077 |
(1.8) |
60340 |
0.49 |
0.47-0.52 |
|
No |
31891 |
(3.6) |
882298 |
1.0 |
Reference |
|
Not known |
1615 |
(3.5) |
46360 |
0.96 |
0.92-1.01 |
Body Mass Index (kg/m2) |
<18.5 |
951 |
(4.0) |
23543 |
1.12 |
1.05-1.19 |
|
20-24.9 |
20428 |
(3.6) |
563735 |
1.0 |
Reference |
|
25-29.9 |
7563 |
(3.4) |
222729 |
0.94 |
0.91-0.96 |
|
≥30 |
3022 |
(2.9) |
103740 |
0.80 |
0.77-0.84 |
|
Not known |
2600 |
(3.5) |
74627 |
0.96 |
0.92-1.00 |
Maternal height (cm) |
<155 |
1159 |
(4.2) |
27892 |
1.21 |
1.14-1.28 |
|
155-164 |
11704 |
(3.6) |
325729 |
1.05 |
1.02-1.07 |
|
165-174 |
16745 |
(3.4) |
488258 |
1.0 |
Reference |
|
≥175cm |
3332 |
(3.3) |
99815 |
0.97 |
0.94-1.01 |
|
Not known |
1643 |
(3.5) |
47298 |
1.01 |
0.96-1.07 |
Maternal educational level |
≤Primary/lower secondary |
1972 |
(2.3) |
86794 |
0.55 |
0.52-0.57 |
|
Upper secondary |
9675 |
(2.9) |
333887 |
0.70 |
0.68-0.72 |
|
<3 yrs higher education |
4280 |
(3.6) |
119622 |
0.86 |
0.83-0.89 |
|
≥3 yrs higher education |
15999 |
(4.2) |
385437 |
1.00 |
Reference |
|
Not known |
2657 |
(4.2) |
63258 |
1.01 |
0.97-1.05 |
Maternal country of birth |
Nordic countries |
30112 |
(3.5) |
860890 |
1.00 |
Reference |
|
Europe/USA/ Canada/Australia/NZ |
698 |
(3.4) |
20409 |
0.98 |
0.97-1.04 |
|
Other |
3773 |
(3.5) |
107699 |
1.00 |
0.97-1.05 |
Delivery mode |
Non-instrumental |
23946 |
(2.6) |
905290 |
1.00 |
Reference |
|
VE |
10314 |
(12.6) |
81932 |
4.76 |
4.66-4.87 |
|
Forceps |
323 |
(18.2) |
1776 |
6.88 |
6.23-7.59 |