Table 4.
Model for logistic regression assessing risk of still births, preterms, and small for gestational age, according to maternal hemoglobin value in Peruvian pregnant women, 2003–2006
| Characteristic | Stillbirth (666) |
Preterm Births (2,880) |
SGA Births (6,011) |
||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| n | % | (CI 95%) | OR | CI 95% | n | % | (CI 95%) | OR | CI 95% | n | % | (CI 95%) | OR | CI 95% | |
| Hemoglobin, g/dl | |||||||||||||||
| <9 | 29 | 7.2 | (4.8–10.1) | 4.42 | 2.82–6.71 | 75 | 18.6 | (14.9–22.7) | 2.5 | 1.9–3.2 | 68 | 16.9 | (13.3–20.8) | 1.4 | 1.1–1.9 |
| 9–10.9 | 71 | 1.9 | (1.5–2.4) | 1.78 | 1.32–2.38 | 313 | 8.5 | (7.6–9.4) | 1.2 | 1.1–1.4 | 389 | 10.6 | (9.6–11.6) | 0.9 | 0.8–1.1 |
| 11–12.9 | 183 | 1.4 | (1.2–1.6) | 1.0 | referent | 978 | 7.6 | (7.2–8.1) | 1.0 | referent | 1724 | 13.4 | (12.8–14.0) | 1.0 | referent |
| >12.9 | 383 | 2.1 | (1.8–2.3) | 1.07 | 0.89–1.29 | 1514 | 8.2 | (7.7–8.6) | 0.9 | 0.8–1.01 | 3830 | 20.7 | (20.1–21.2) | 1.3 | 1.2–1.4 |
| Altitude | |||||||||||||||
| Low | 64 | 0.8 | (0.5–1.0) | 1.0 | referent | 539 | 6.4 | (5.8–6.9) | 1.0 | referent | 721 | 8.5 | (7.9–9.2) | 1.0 | referent |
| High | 602 | 2.2 | (2.0–2.4) | 3.90 | 2.89–5.28 | 2342 | 8.7 | (8.3–8.9) | 1.83 | 1.6–2.1 | 5287 | 19.6 | (19.1–20.0) | 2.2 | 2.0–2.4 |
| Age (years) | |||||||||||||||
| <20 | 96 | 1.6 | (1.2–1.8) | 0.84 | 0.65–1.08 | 573 | 9.2 | (8.4–9.9) | 1.24 | 1.1–1.4 | 1375 | 22.0 | (21.0–23.1) | 1.0 | 0.9–1.1 |
| 20–34 | 429 | 1.7 | (1.5–1.8) | 1.0 | referent | 1859 | 7.4 | (7.1–7.7) | 1.0 | referent | 4002 | 15.9 | (15.5–16.4) | 1.0 | referent |
| >34 | 141 | 3.5 | (2.8–3.9) | 1.20 | 0.96–1.52 | 449 | 10.7 | (9.8–11.7) | 1.16 | 1.02–1.3 | 631 | 15.1 | (14.0 16.2) | 1.1 | 1.0–1.3 |
| Education | |||||||||||||||
| None | 71 | 7.9 | (6.2–9.8) | 3.19 | 2.37–4.31 | 132 | 14.6 | (12.3–17.4) | 1.56 | 1.3–1.9 | 193 | 21.4 | (18.7–24.2) | 1.3 | 1.1–1.6 |
| Primary | 198 | 3.6 | (3.0–3.9) | 1.71 | 1.40–2.08 | 617 | 10.7 | (9.9–11.5) | 1.26 | 1.1–1.4 | 1178 | 20.5 | (19.4–21.5) | 1.2 | 1.1–1.3 |
| Secondary | 280 | 1.5 | (1.3–1.7) | 1.0 | referent | 1421 | 7.72 | (7.3–8.1) | 1.00 | referent | 3053 | 16.6 | (16.1–17.1) | 1.0 | referent |
| Superior | 117 | 1.1 | (0.9–1.3) | 0.73 | 0.58–0.91 | 711 | 6.83 | (6.3–7.3) | 0.92 | 0.8–1.02 | 1584 | 15.2 | (14.5–15.9) | 0.8 | 0.7–0.9 |
| Parity | |||||||||||||||
| None | 223 | 1.5 | (1.2–1.7) | 1.0 | referent | 1171 | 7.7 | (7.2–8.1) | 1.0 | referent | 3164 | 20.6 | (20.0 21.3) | 1.0 | referent |
| 1–3 | 305 | 1.8 | (1.5–2.0) | 1.03 | 0.84–1.25 | 1332 | 7.8 | (7.4–8.2) | 1.07 | 0.98–1.2 | 2392 | 14.0 | (13.5–14.5) | 2.0 | 1.8–2.3 |
| >3 | 138 | 4.4 | (3.7–5.2) | 1.26 | 0.93–1.70 | 378 | 12.1 | (11–13.3) | 1.28 | 1.1–1.5 | 452 | 14.5 | (13.3–15.8) | 1.3 | 1.1–1.5 |
| Prev Perin death/preterm* | 88 | 4.9 | (4.1–7.3) | 2.05 | 1.46–2.87 | 269 | 15.0 | (12–17.1) | 1.71 | 1.4–2.1 | 342 | 19.0 | (15.4–20.8) | 1.2 | 1.1–1.5 |
| Placental abruption | 17 | 13.9 | (8.9–22.3) | 7.52 | 4.40–12.8 | 44 | 36.0 | (27–45.2) | 5.42 | 3.6–8.0 | 25 | 20.4 | (13.7–15.7) | 1.3 | 0.8–2.0 |
| Gestational hypertension | 30 | 2.4 | (1.2–1.6) | 1.23 | 0.84–1.80 | 280 | 22.7 | (20.3–25) | 3.88 | 3.4–4.5 | 294 | 23.9 | (21.5–26.4) | 1.6 | 1.4–1.8 |
| Prenatal care | |||||||||||||||
| None | 211 | 3.13 | (2.7–3.5) | 3.08 | 2.52–3.76 | 762 | 11.3 | (10.5–12.1) | 2.81 | 2.5–3.1 | 1119 | 16.6 | (15.7–17.5) | 1.2 | 1.1–1.3 |
| 1–5 | 227 | 2.55 | (2.2–2.8) | 2.12 | 1.75–2.56 | 1141 | 12.8 | (12.1–13.5) | 3.15 | 2.9–3.5 | 1570 | 17.6 | (16.8 18.4) | 1.0 | 0.96–1.1 |
| >5 | 228 | 1.15 | (1.0–1.3) | 1.0 | referent | 978 | 4.9 | (4.6–5.2) | 1.0 | referent | 3319 | 16.7 | (16.2–17.3) | 1.0 | referent |
| BMI, kg/m2 | |||||||||||||||
| <19.9 | 67 | 1.87 | (1.4–2.3) | 0.98 | 0.74–1.31 | 335 | 9.4 | (8.4–10.3) | 1.13 | 1.0–1.3 | 765 | 21.3 | (20.0–22.7) | 1.3 | 1.2–1.4 |
| 19.9–25 | 413 | 1.83 | (1.6–2.0) | 1.0 | referent | 1865 | 8.3 | (7.9–8.6) | 1.0 | referent | 4018 | 17.8 | (17.3–18.3) | 1.0 | referent |
| >25 | 186 | 1.99 | (1.7–2.3) | 1.03 | 0.85–1.23 | 681 | 7.3 | (6.7–7.8) | 0.83 | 0.8–0.9 | 1225 | 13.1 | (16.2–17.3) | 0.7 | 0.6–0.8 |
| Measurement of Hb | |||||||||||||||
| 1st trimester | 72 | 1.4 | (1.1–1.8) | 1.0 | referent | 386 | 7.7 | (6.9–8.5) | 1.0 | referent | 741 | 14.8 | (13.8–15.8) | 1.0 | referent |
| 2nd trimester | 279 | 1.6 | (1.4–1.8) | 1.0 | 0.7–1.3 | 1394 | 8.3 | (7.9–8.8) | 1.1 | 0.9–1.2 | 2628 | 15.8 | (15.2–16.3) | 0.9 | 0.8–1.1 |
| 3rd trimester | 315 | 2.2 | (2.0–2.5) | 1.1 | 0.8–1.4 | 1100 | 7.9 | (7.5–8.4) | 0.7 | 0.6–0.8 | 2642 | 19.2 | (18.5–19.8) | 1.23 | 1.1–1.4 |
n = number of cases with fetal adverse outcome.
*
Previous perinatal death and/or preterm births. Marital status was also included in the model but it has no impact on the outcome. Then, it was removed. OR, Odds ratio; CI 95%, confidence interval at 95%; BMI, body mass index.