Table 1.
Maternal characteristics at study entry (first birth in the included cohort)* for the within-women analysis (n = 1,233,688).
Table 2.
Interpregnancy interval distribution for births in within-women analyses across the four countries (n = 2,905,703).
Table 3.
Adjusted odds ratios (aOR) and 95% confidence intervals (CI) between interpregnancy interval and adverse birth outcomes among births in between-women* and within-women** analyses across the four countries.
Fig 1.
Adjusted odds ratios of within-women analysis for the association between interpregnancy interval and preterm birth as compared to 18–23 months interpregnancy interval by country.
IPI—Interpregnancy interval. *Adjusted Odds ratios (aOR) and corresponding 95% confidence intervals, adjusted for maternal age, parity, and birth year; the reference IPI category is 18–23 months. **Weights are derived from inverse-variance.
Fig 2.
Adjusted odds ratios for within-women analysis for the association between interpregnancy interval and spontaneous preterm birth as compared to 18–23 months of interpregnancy interval by country.
IPI—interpregnancy interval. *Adjusted Odds ratios (aOR) and corresponding 95% confidence intervals, adjusted for maternal age, parity, and birth year; the reference IPI category is 18–23 months. **Weights are derived from inverse-variance.
Fig 3.
Adjusted odds ratios for the within-women analysis for the association between interpregnancy interval and small-for-gestational age birth as compared to 18–23 months of interpregnancy interval by country.
IPI—interpregnancy interval. *Adjusted Odds ratios (aOR) and corresponding 95% confidence intervals, adjusted for maternal age, parity, and birth year; the reference IPI category is 18–23 months. **Weights are derived from inverse-variance.