| Norway | Somalia | Iraq | Afghanistan | Kosovo | ||||
---|---|---|---|---|---|---|---|---|---|
 | n = 6826 | n = 278 | P-value* | n = 166 | P-value* | n = 71 | P-value* | n = 67 | P-value* |
Duration of residence in Norway prior birth, years, median (interquartile range) | 32 (6) | 6 (8) | <0.001†| 5 (5) | <0.001†| 2 (5) | <0.001†| 6 (6) | <0.001†|
 ≤1 | – | 60 (21.6) |  | 37 (22.3) |  | 22 (31.0) |  | 15 (22.4) |  |
 2–5 | – | 67 (24.1) |  | 60 (36.1) |  | 30 (42.3) |  | 16 (23.9) |  |
 6–10 | – | 87 (31.3) |  | 47 (28.3) |  | 16 (22.5) |  | 23 (34.3) |  |
 >10 | 6826 (100.0) | 64 (23.0) |  | 22 (13.3) |  | 3 (4.2) |  | 13 (19.4) |  |
Maternal age, years, mean (SD) | 31.8 (4.5) | 28.8 (6.0) | <0.001§ | 28.0 (5.7) | <0.001§ | 26.4 (4.9) | <0.001§ | 27.6 (5.9) | <0.001§ |
 Teenage mothers (17–19 years) | 24 (0.4) | 10 (3.6) | <0.001‡ | 11 (6.6) | <0.001‡ | 3 (4.2) | 0.003‡ | 3 (4.5) | 0.002‡ |
Marital status |  |  | <0.001 |  | 0.003 |  | 0.408‡ |  | <0.001‡ |
 Married/cohabiting | 6482 (95.0) | 180 (64.7) |  | 149 (89.8) |  | 66 (93.0) |  | 55 (82.1) |  |
 Single | 344 (5.0) | 98 (35.3) |  | 17 (10.2) |  | 5 (7.0) |  | 12 (17.9) |  |
Educational level |  |  | <0.001a,‡ |  | <0.001a,‡ |  | <0.001a,‡ |  | <0.001a,‡ |
 <12 years | 1905 (27.9) | 192 (69.1) |  | 89 (53.6) |  | 43 (60.6) |  | 35 (52.2) |  |
 ≥12 years | 4918 (72.0) | 10 (3.6) |  | 27 (16.3) |  | 7 (9.9) |  | 9 (13.4) |  |
 Undocumented | 3 (0.0) | 76 (27.3) |  | 50 (30.1) |  | 21 (29.6) |  | 23 (34.3) |  |
Parity | Â | Â | <0.001 | Â | 0.030 | Â | 0.972 | Â | 0.017 |
 Para 0 | 3543 (51.9) | 72 (25.9) |  | 72 (43.4) |  | 37 (52.1) |  | 25 (37.3) |  |
 Para +1 | 3283 (48.1) | 206 (74.1) |  | 94 (56.6) |  | 34 (47.9) |  | 42 (62.7) |  |
Previous stillbirthb | 12 (0.4) | 4 (1.9) | 0.012‡ | 0 | 1.000‡ | 0 | 1.000‡ | 0 | 1.000‡ |
Previous cesarean sectionb | 512 (15.6) | 41 (19.9) | 0.101 | 8 (8.5) | 0.061 | 4 (11.8) | 0.540 | 4 (9.5) | 0.280 |
Health issues before pregnancyc | 1369 (20.1) | 20 (7.2) | <0.001 | 23 (13.9) | 0.048 | 7 (9.9) | 0.032 | 9 (13.4) | 0.177 |
Health issues during pregnancyd | 999 (14.6) | 46 (16.5) | 0.378 | 21 (12.7) | 0.474 | 6 (8.5) | 0.142 | 3 (4.5) | 0.019 |
 Diabetes mellitus type 2 or gestational diabetes | 51 (0.7) | 6 (2.2) | 0.023‡ | 3 (1.8) | 0.136‡ | 1 (1.4) | 0.417‡ | 2 (3.0) | 0.094‡ |
 Anemia (hemoglobin level <9 g/dL) | 59 (0.9) | 31 (11.2) | <0.001‡ | 7 (4.2) | 0.001‡ | 4 (5.6) | 0.004‡ | 0 | 1.000‡ |
Twin birth | 59 (0.9) | 2 (0.7) | 1.000‡ | 3 (1.8) | 0.182‡ | 0 | 1.000‡ | 1 (1.5) | 0.455‡ |
Cigarette smokinge | Â | Â | Â | Â | Â | Â | Â | Â | Â |
 Start of pregnancy | 692 (10.1) | 7 (2.5) | <0.001 | 2 (1.2) | <0.001 | 1 (1.4) | 0.015 | 8 (11.9) | 0.627 |
 End of pregnancy | 205 (3.0) | 5 (1.8) | 0.245 | 1 (0.6) | 0.097 | 0 | 0.276 | 6 (9.0) | 0.016 |