Table 5 Odds ratio (OR) for stillbirth (335 stillbirths) among 234 719 singleton births by size at birth (small-for-gestational-age [SGA] or non-SGA) and method of gestational age estimation, analyzed with fetus at risk approach, Norway, 1999-2006
Gestational age by last menstrual period | Stillbirths n (%) | |||||||
|---|---|---|---|---|---|---|---|---|
Non-SGA | SGA | |||||||
Gestational age in weeks | Stillbirths n (%) | Ongoing pregnancies (n) | Stillbirths per 1000 | Stillbirths n (%) | Ongoing pregnancies (n) | Stillbirths Per 1000 | AdjustedαOR (95% CI) | |
37 | 15 (6.0) | 221 151 | 0.07 | 8 (9.6) | 13 568 | 0.59 | 7.4 (3.1–17.7) | 23 (6.9) |
38 | 37 (14.7) | 213 617 | 0.17 | 15 (18.1) | 12 917 | 1.16 | 7.7 (4.1–13.8) | 52 (15.5) |
39 | 49 (19.5) | 191 764 | 0.26 | 24 (28.9) | 11 207 | 2.14 | 8.6 (5.2–14.1) | 73 (21.8) |
40 | 61(24.2) | 146 679 | 0.42 | 10 (12.0) | 8 029 | 1.25 | 3.1 (1.6–6.0) | 71 (21.2) |
41 | 52 (20.6) | 82 300 | 0.63 | 13 (15.7) | 4 258 | 3.05 | 4.8 (2.6–8.9) | 65 (19.4) |
≥42 | 38 (15.1) | 30 689 | 1.24 | 13 (15.7) | 1 522 | 8.54 | 7.0 (3.7–13.3) | 51 (15.2) |
Total | 252 (100) | - | - | 83 (100) | - | - | - | 335 (100) |
Gestational age by ultrasound | ||||||||
37 | 31 (12.3) | 221 151 | 0.14 | 11 (13.2) | 13 568 | 0.81 | 6.1 (3.0–12.2) | 42 (12.5) |
38 | 38 (15.0) | 212 557 | 0.18 | 25 (30.1) | 12 944 | 1.93 | 11.3 (6.7–18.8) | 63 (18.8) |
39 | 48 (19.1) | 185 384 | 0.26 | 19 (22.9) | 11 019 | 1.72 | 6.8 (4.0–11.7) | 67 (20.0) |
40 | 69 (27.4) | 132 559 | 0.52 | 13 (15.7) | 7 156 | 1.82 | 3.7 (2.0–6.7) | 82 (24.5) |
41 | 44 (17.5) | 64 786 | 0.68 | 10 (12.1) | 2 956 | 3.38 | 4.7 (2.3–9.3) | 54 (16.1) |
≥42 | 22 (8.7) | 18 779 | 1.17 | 5 (6.0) | 714 | 7.00 | 6.3 (2.3–16.9) | 27 (8.1) |
Total | 252 (100) | - | - | 83 (100) | - | - | - | 335 (100) |