The association between stillbirth and pregnancy-related factors: frequencies, unadjusted and adjusted ORs
| Variables | Total births N=886 505 Frequency (%) | Stillbirths N=8429 Frequency (%) | Live births N=878 076 Frequency (%) | Unadjusted OR (95% CI*) | Adjusted OR† (95% CI*) |
| Number of antenatal care visit | |||||
| Four or more | 269 148 (28.9) | 2222 (24.6) | 266 926 (29.0) | 1.00 (Ref) | 1.00 (Ref) |
| Less than four | 518 288 (58.7) | 4939 (59.3) | 513 349 (58.6) | 1.19 (1 12 to 1.26) | 1.08 (1.01 to 1.15) |
| Missing | 99 069 (12.4) | 1268 (16.1) | 97 801 (12.4) | 1.53 (1.41 to 1.66) | 1.36 (1.25 to 1.48) |
| Timing of the first antenatal care visit | |||||
| Three or less | 534 118 (58.6) | 4678 (54.0) | 529 440 (58.7) | 1.00 (Ref) | – |
| More than three | 253 460 (28.9) | 2483 (29.9) | 250 977 (28.9) | 1.12 (1.06 to 1.19) | – |
| Missing | 98 927 (12.4) | 1268 (16.1) | 97 659 (12.4) | 1.41 (1.31 to 1.52) | – |
| Place of delivery | |||||
| Medical facility | 539 704 (60.5) | 5176 (61.9) | 534 528 (60.5) | 1.00 (Ref) | – |
| Home | 346 801 (39.5) | 3253 (38.1) | 343 548 (39.5) | 0.94 (0.89 to 0.99) | – |
| Number of pregnancies | |||||
| One | 158 886 (16.9) | 957 (10.6) | 157 929 (16.9) | 1.00 (Ref) | 1.00 (Ref) |
| Two to four | 414 938 (46.8) | 4409 (51.8) | 410 529 (46.7) | 1.77 (1.63 to 1.93) | 3.06 (2.42 to 3.86) |
| Five or more | 93 458 (11.7) | 1404 (19.0) | 92 024 (11.7) | 2.60 (2.36 to 2.87) | 4.98 (3.66 to 6.74) |
| Missing | 219 253 (24.7) | 1659 (18.6) | 217 594 (24.7) | 1.21 (1.10 to 1.32) | 1.40 (0.68 to 2.90) |
| Sex of the baby | |||||
| Female | 414 913 (46.6) | 3468 (41.2) | 411 445 (46.7) | 1.00 (Ref) | 1.00 (Ref) |
| Male | 471 592 (53.4) | 4961 (58.9) | 466 631 (53.3) | 1.25 (1.19 to 1.32) | 1.26 (1.20 to 1.33) |
| Multiple gestations (index pregnancy) | |||||
| Singleton | 878 556 (99.1) | 8267 (98.2) | 870 289 (99.1) | 1.00 (Ref) | 1.00 (Ref) |
| Twin pregnancy | 7949 (0.9) | 162 (1.8) | 7787 (0.9) | 2.03 (1.67 to 2.45) | 1.77 (1.47 to 2.15) |
| Mode of delivery | |||||
| Spontaneous vaginal | 805 430 (90.7) | 7146 (84.3) | 798 284 (90.8) | 1.00 (Ref) | 1.00 (Ref) |
| Assisted vaginal | 14 909 (1.8) | 390 (5.0) | 14 519 (1.7) | 3.13 (2.76 to 3.55) | 3.45 (3.02 to 3.93) |
| Caesarean section | 66 166 (7.6) | 893 (10.7) | 65 273 (7.5) | 1.53 (1.40 to 1.66) | 1.73 (1.58 to 1.89) |
| Any pregnancy complications | |||||
| No | 250 099 (28.1) | 2000 (23.5) | 250 099 (28.1) | 1.00 (Ref) | 1.00 (Ref) |
| Yes | 418 856 (47.5) | 4779 (58.0) | 414 077 (47.4) | 1.47 (1.38 to 1.56) | 1.42 (1.33 to 1.51) |
| Missing | 217 550 (24.5) | 1650 (18.5) | 215 900 (24.5) | 0.91 (0.84 to 0.98) | 1.99 (1.00 to 3.94) |
Frequencies are true counts, % and OR are weighted for design effects and non-response.
*Multivariable logistic regression, adjusting for the other variables in the model, except self-reported mental illness. The model also adjusts for the observed significant interaction between gravidity and asset index.
†The 95% CIs were calculated using linearised SEs.