Table 2.
Exposure models of adverse outcomes of pregnancy by birth interval
| Birth interval (months) | N | Events | Crude OR* | 95% CI | Adjusted OR † | 95% CI | |||
|---|---|---|---|---|---|---|---|---|---|
| N | /1,000 | ||||||||
| Adverse outcome of pregnancy | |||||||||
| >45 | 3,173 | 143 | 45.1 | reference | reference | ||||
| 33-44 | 1,030 | 54 | 52.4 | 1.19 | 0.86 | 1.65 | 1.21 | 0.87 | 1.70 |
| 21-32 | 879 | 42 | 47.8 | 1.07 | 0.75 | 1.52 | 1.13 | 0.78 | 1.65 |
| <21 | 489 | 44 | 90.0 | 2.12 | 1.49 | 3.03 | 2.23 | 1.51 | 3.29 |
| Perinatal mortality | |||||||||
| >45 | 3,173 | 124 | 39.1 | reference | reference | ||||
| 33-44 | 1,030 | 50 | 48.5 | 1.29 | 0.92 | 1.82 | 1.31 | 0.92 | 1.87 |
| 21-32 | 879 | 37 | 42.1 | 1.09 | 0.75 | 1.59 | 1.15 | 0.77 | 1.71 |
| <21 | 489 | 41 | 83.8 | 2.31 | 1.60 | 3.35 | 2.33 | 1.55 | 3.50 |
| Still birth rate | |||||||||
| >45 | 3,173 | 79 | 24.9 | reference | reference | ||||
| 33-44 | 1,030 | 28 | 27.2 | 1.09 | 0.70 | 1.69 | 1.10 | 0.70 | 1.73 |
| 21-32 | 879 | 19 | 21.6 | 0.85 | 0.51 | 1.42 | 0.92 | 0.54 | 1.56 |
| <21 | 489 | 25 | 51.1 | 2.10 | 1.32 | 3.33 | 2.13 | 1.28 | 3.53 |
| Neonatal mortality | |||||||||
| >45 | 3094 | 64 | 20.7 | reference | reference | ||||
| 33-44 | 1002 | 26 | 25.9 | 1.31 | 0.82 | 2.09 | 1.35 | 0.83 | 2.20 |
| 21-32 | 860 | 23 | 26.7 | 1.32 | 0.82 | 2.16 | 1.38 | 0.83 | 2.32 |
| <21 | 464 | 19 | 40.9 | 2.10 | 1.24 | 3.55 | 2.28 | 1.28 | 4.05 |
| Early neonatal mortality | |||||||||
| >45 | 3094 | 45 | 14.5 | reference | reference | ||||
| 33-44 | 1002 | 22 | 22.0 | 1.66 | 0.98 | 2.81 | 1.68 | 0.65 | 1.84 |
| 21-32 | 860 | 18 | 20.9 | 1.51 | 0.87 | 2.65 | 1.54 | 0.55 | 2.23 |
| <21 | 464 | 16 | 34.5 | 2.63 | 1.46 | 4.74 | 2.59 | 0.53 | 2.73 |
*The crude analyses were adjusted for clustering.
†The OR’s were adjusted for maternal age, parity, previous birth outcome, maternal religion, education and household assets, tea garden residence and clustering.