TABLE 2.
Meta‐analysis II for the associations between interpregnancy interval and risk of adverse pregnancy and birth outcomes subsequent to preterm birth or pregnancy loss (miscarriage, stillbirth, or induced abortion).
| Adverse outcomes | No. of studies | <6 months | 6–11 months | 12–17 months | 18–23 months | 24–59 months | ≥60 months | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Pooled OR (95% CI) | I 2 (%) | Pooled OR (95% CI) | I 2 (%) | Pooled OR (95% CI) | I 2 (%) | OR | Pooled OR (95% CI) | I 2 (%) | Pooled OR (95% CI) | I 2 (%) | ||
| After preterm births | ||||||||||||
| Preterm birth | 5 studies 18 , 54 , 71 , 90 , 105 | 1.45 (1.25–1.68) | 71.3 | 1.10 (1.00–1.21) | 56.1 | 1.03 (0.97–1.09) | 3.8 | 1.00 | 1.03 (0.94–1.14) | 75.0 | 1.29 (1.03–1.63) | 70.9 |
| After pregnancy losses | ||||||||||||
| Birth outcomes | ||||||||||||
| Preterm birth | 7 studies 12 , 14 , 65 , 70 , 91 , 103 , 121 | 1.21 (0.7–1.86) | 98.2 | 0.97 (0.88–1.06) | 84.1 | 0.99 (0.95–1.03) | 0.0 | 1.00 | 0.99 (0.96–1.01) | 0.0 | 1.03 (0.96–1.10) | 63.9 |
| Low birthweight | 5 studies 14 , 65 , 70 , 91 , 121 | 1.64 (1.10–2.44) | 93.8 | 1.03 (0.93–1.14) | 57.5 | 1.00 (0.96–1.05) | 0.0 | 1.00 | 1.02 (0.97–1.06) | 0.0 | 1.08 (0.93–1.24) | 93.0 |
| Small for gestational age | 5 studies 14 , 70 , 91 , 103 , 121 | 1.03 (0.83–1.29) | 70.2 | 1.00 (0.87–1.15) | 89.7 | 1.00 (0.86–1.17) | 19.1 | 1.00 | 0.99 (0.94–1.04) | 34.1 | 1.07 (0.99–1.15) | 31.3 |
| Fetal death | 3 studies 65 , 103 , 121 | 1.07 (0.83–1.38) | 0.0 | 1.00 (0.87–1.16) | 0.0 | 1.01 (0.87–1.16) | 0.0 | 1.00 | 1.01 (0.88–1.16) | 0.0 | — | — |
| Pregnancy outcomes | ||||||||||||
| Miscarriage | 3 studies 11 , 65 , 93 | 0.76 (0.54–1.08) | 16.7 | — | — | 1.07 (0.81–1.41) | 2.2 | 1.00 | 0.98 (0.77–1.26) | 0.0 | — | — |
| Preeclampsia | 2 studies 65 , 121 | 1.04 (0.90–1.20) | 0.0 | 1.04 (0.87–1.23) | 33.2 | 1.10 (0.96–1.25) | 0.0 | 1.00 | 1.06 (0.94–1.20) | 0.0 | — | — |
Abbreviations: CI, confidence interval; OR, odds ratio.