Table 3. Univariate analysis of short and long birth intervals, socioeconomic and reproductive health variables, and maternal morbidity.
| Variables | Short interval* | Long interval* | p-value |
|---|---|---|---|
| OR (95%CI) | OR (95%CI) | ||
| Skin color | 0.02 | ||
| White | Ref. | Ref. | |
| Nonwhite | 1.33 (0.98–1.80) | 0.86 (0,69–1,06) | |
| Age (years old) | < 0.01 | ||
| < 20 | 0.75 (0.52–1.08) | 0.05 (0.02–0.12) | |
| 20–34 | Ref. | Ref. | |
| ≥ 35 | 1.09 (0.74–1.62) | 2.66 (2.04–3.46) | |
| Education level (years) | |||
| < 9 | Ref. | Ref. | < 0.01 |
| ≥ 9 | 0.80 (0.65–1.00) | 1.43 (1.19–1.71) | |
| Economic status | < 0.01 | ||
| A–B | Ref. | Ref. | |
| C | 1.07 (0.76–1.50) | 0.76 (0.60–0.98) | |
| D–E | 1.05 (0.74–1.49) | 0.41 (0.32–0.53) | |
| Type of delivery | < 0.01 | ||
| Normal | Ref. | Ref. | |
| Cesarean section | 1.05 (0.85–1.30) | 1.50 (1.26–1.77) | |
| Number of prenatal visits | < 0.01 | ||
| < 6 | Ref. | Ref. | |
| ≥ 6 | 1.27 (1.00–1.62) | 0.45 (0.37–0.53) | |
| Number of births | < 0.01 | ||
| 2 | Ref. | Ref. | |
| ≥ 3 | 1.38 (1.11–1.70) | 0.68 (0.57–0.81) | |
| High blood pressure | 0.17 | ||
| No | Ref. | Ref. | |
| Yes | 1.00 (0.75–1.35) | 0.82 (0.65–1.02) | |
| Diabetes | < 0.01 | ||
| No | Ref. | Ref. | |
| Yes | 0.41 (0.18–0.93) | 0.25 (0.13–0.46) | |
| Bleeding in 3rd trimester | 0.69 | ||
| No | Ref. | Ref. | |
| Yes | 0.90 (0.63–1.29) | 0.89 (0.67–1.18) | |
| Anemia | 0.13 | ||
| No | Ref. | Ref. | |
| Yes | 0.98 (0.79–1.21) | 1.17 (0.99–1.38) |
Abbreviations: CI, confidence interval; OR, odds ratio.
*
Reference category: adequate birth interval.