Association of sociodemographic factors with recurrent preterm birth in subsequent births in Matlab, Bangladesh, 1990–2019 (n=2515)
| No of birth in second pregnancy | Recurrent preterm birth odds | |||
| Live birth | Preterm birth | Model 1* OR (95% CI) | Model 2†‡ OR (95% CI) | |
| Maternal age in years | ||||
| <20 | 195 | 69 | 1.90 (1.36 to 2.64) | 1.38 (0.95 to 2.01) |
| 20–24 | 1347 | 368 | 1.30 (1.17 to 1.58) | 1.18 (0.96 to 1.45) |
| ≥25§ | 973 | 218 | 1 | 1 |
| Education in years | ||||
| 0 | 764 | 233 | 1.57 (1.27 to 1.94) | 1.20 (0.93 to 1.54) |
| 1–5 | 722 | 194 | 1.29 (1.03 to 1.61) | 1.09 (0.86 to 1.39) |
| ≥6§ | 1029 | 228 | 1 | 1 |
| Wealth quintiles | ||||
| 1-poorest | 519 | 155 | 1.67 (1.25 to 2.25) | 1.53 (1.12 to 2.10) |
| 2 | 475 | 129 | 1.93 (1.45 to 2.56) | 1.78 (1.32 to 2.41) |
| 3 | 509 | 128 | 1.37 (1.03 to 1.82) | 1.30 (0.97 to 1.75) |
| 4 | 551 | 146 | 1.48 (1.12 to 1.96) | 1.49 (1.12 to 1.99) |
| 5-wealthiest§ | 461 | 97 | 1 | 1 |
| Birth interval in months | ||||
| <18 | 180 | 75 | 2.23 (1.62 to 3.08) | 1.81 (1.27 to 2.58) |
| 18–23 | 152 | 48 | 1.44 (1.00 to 2.08) | 1.13 (0.77 to 1.68) |
| 24–47 | 851 | 209 | 1.02 (0.83 to 1.24) | 0.89 (0.72 to 1.10) |
| ≥48§ | 1332 | 323 | 1 | 1 |
| Calendar year of second birth | ||||
| 1990–1999 | 912 | 279 | 1.64 (1.29 to 2 .09) | 1.38 (1.04 to 1.82) |
| 2000–2009 | 1009 | 250 | 1.22 (0.96 to 1 .56) | 1.16 (0.90 to 1.50) |
| 2010–2019§ | 594 | 126 | 1 | 1 |
*Model 1: crude OR.
†Model 2: adjusted for maternal age, education, socioeconomic status by wealth quintiles, birth interval and calendar year of second birth.
‡Hosmer and Lemeshow goodness-of-fit test p=0.343.
§Reference category.