Participants' characteristics and risk factors for miscarriage
| Overall (N=1134) | Miscarriage (N=89) | Other pregnancy outcomes (n=1045) | HR (95% CI) | p Values | |
|---|---|---|---|---|---|
| Gestational age at pregnancy detection in weeks (mean (SD)) | 13.3 (6.9; 0–27.9) | 7.8 (4.4) | 13.7 (6.9) | 0.94 (0.88 to 1.01) | 0.094 |
| Age in years (mean (SD)) | 26.1 (6.8) | 29.5 (7.9) | 25.8 (6.6) | 1.08 (1.04 to 1.11) | <0.001 |
| Age categories | <0.001 | ||||
| 15–20 | 285 (25.1) | 14 (15.7) | 271 (25.9) | 1 | |
| 21–25 | 287 (25.3) | 14 (15.7) | 273 (26.1) | 0.9 (0.42 to 1.9) | |
| 26–30 | 255 (22.5) | 16 (18.0) | 239 (22.9) | 1.14 (0.57 to 2.3) | |
| 31–35 | 179 (15.8) | 21 (23.6) | 158 (15.1) | 2.31 (1.2 to 4.44) | |
| >35 | 128 (11.3) | 24 (27.0) | 104 (10.0) | 4.02 (2.08 to 7.76) | |
| Education level | 0.713 | ||||
| None/primary not completed | 495 (44.4) | 38 (43.7) | 457 (44.4) | 1 | |
| Primary completed | 533 (47.8) | 44 (50.6) | 489 (47.5) | 1.07 (0.69 to 1.66) | |
| Secondary completed | 88 (7.9) | 5 (5.8) | 83 (8.1) | 0.69 (0.23 to 2.04) | |
| Missing | 18 | 2 | 16 | ||
| Occupation | <0.001 | ||||
| Not working | 379 (34.4) | 22 (25.6) | 357 (35.1) | 1 | |
| Farming | 369 (33.5) | 39 (45.4) | 330 (32.5) | 1.47 (0.88 to 2.45) | |
| Small business/skilled labour/salaried | 335 (30.4) | 19 (22.1) | 316 (31.1) | 0.88 (0.48 to 1.6) | |
| Other | 20 (1.8) | 6 (7.0) | 14 (1.4) | 5.15 (2.15 to 12.34) | |
| Missing | 31 | 2 | 16 | ||
| Marital status | 0.224 | ||||
| Single | 240 (21.5) | 22 (25.3) | 218 (21.2) | 1 | |
| Married | 876 (78.51) | 65 (74.7) | 811 (78.8) | 0.74 (0.46 to 1.2) | |
| Missing | 18 | 2 | 16 | ||
| Household wealth quintiles | 0.024 | ||||
| Poorest | 105 (9.7) | 18 (20.5) | 87 (8.8) | 1 | |
| Very poor | 158 (14.6) | 9 (10.2) | 149 (15.0) | 0.33 (0.15 to 0.75) | |
| Poor | 220 (20.4) | 16 (18.2) | 204 (25.6) | 0.4 (0.2 to 0.81) | |
| Less poor | 269 (24.9) | 22 (25.0) | 247 (24.9) | 0.47 (0.25 to 0.88) | |
| Least poor | 328 (30.4) | 23 (26.1) | 305 (30.8) | 0.39 (0.21 to 0.74) | |
| Missing | 54 | 1 | 53 | ||
| Gravidity | <0.001 | ||||
| Primigravid | 219 (19.6) | 17 (19.3) | 202 (19.6) | 1 | |
| 1–3 pregnancies | 525 (47.0) | 23 (26.1) | 502 (48.8) | 0.49 (0.26 to 0.91) | |
| 4+ pregnancies | 374 (33.5) | 49 (55.1) | 325 (31.6) | 1.63 (0.95 to 2.79) | |
| Missing | 16 | 0 | 16 | ||
| Previous pregnancy loss | 160 (14.3) | 22 (25.0) | 138 (13.4) | 2.23 (1.4 to 3.56) | 0.001 |
| Missing n=17 | Missing n=1 | Missing n=16 | |||
| ANC summary | |||||
| Gestational age at first ANC visit in weeks (mean (SD)) | 20.8 (7.8), range 1.7–41.0 | 10.4 (4.9), missing n=71 | 21.0 (7.7), missing n=227 | 0.85 (0.79 to 0.91) | <0.001 |
| Number of ANC visit | <0.001 | ||||
| None | 89 (8.1) | 66 (74.2) | 23 (2.3) | 1 | |
| 1 | 90 (8.2) | 18 (20.2) | 72 (7.2) | 0.17 (0.1 to 0.29) | |
| 2 | 155 (14.2) | 1 (1.1) | 154 (15.3) | 0 (0 to 0.03) | |
| 3 | 244 (22.3) | 3 (3.4) | 241 (24.0) | 0.01 (0 to 0.03) | |
| 4+ | 517 (47.2) | 1 (1.1) | 516 (51.3) | 0 (0 to 0.01) | |
| Missing | 39 | 0 | 39 | ||
| IPTp doses (HIV negative) | <0.001 | ||||
| None | 242 (28.3) | 73 (98.7) | 169 (21.7) | 1 | |
| 1 | 95 (11.1) | 1 (1.4) | 94 (12.1) | 0.04 (0.01 to 0.31) | |
| 2 | 175 (20.5) | 0 | 175 (22.4) | 0 (0 to 0) | |
| 3 | 222 (26.0) | 0 | 222 (28.5) | 0 (0 to 0) | |
| 4 | 120 (14.1) | 0 | 120 (15.4) | 0 (0 to 0) | |
| Missing | 280 | 18 | 265 | 0 (0 to 0) | |
| Vaginal bleeding | <0.001 | ||||
| No | 813 (97.3) | 14 (77.8) | 799 (97.7) | 1 | |
| Yes | 23 (2.8) | 4 (22.2) | 19 (2.3) | 11.57 (4 to 33.46) | |
| Missing | 298 | 71 | 227 | ||
| ANC profile at first ANC visit | |||||
| HIV positive | <0.001 | ||||
| Negative | 771 (68.0) | 17 (19.0) | 754 (72.2) | 1 | |
| Positive | 262 (23.1) | 27 (30.3) | 235 (22.5) | 4.83 (2.62 to 8.9) | |
| Unknown | 101 (8.9) | 45 (50.6) | 56 (5.4) | 25.83 (14.7 to 45.39) | |
| Hb (mean (SD; range)) | 11.2 (1.9; 4.3–17.2) | 12.4 (1.9) | 11.2 (1.9) | 1.31 (1.05 to 1.63) | 0.017 |
| Missing n=309 | Missing n=72 | Missing n=237 | |||
| Anaemia (Hb <11 g/dL) | 0.184 | ||||
| No | 476 (57.7) | 13 (76.5) | 463 (57.3) | 1 | |
| Yes | 349 (42.3) | 4 (23.5) | 345 (42.7) | 0.47 (0.15 to 1.44) | |
| Missing | 309 | 72 | 237 | ||
| Syphilis reactive test | 0.750 | ||||
| Negative | 838 (92.3) | 20 (95.2) | 818 (92.2) | 1 | |
| Positive | 70 (7.7) | 1 (4.8) | 69 (7.8) | 0.79 (0.18 to 3.47) | |
| Missing | 226 | 68 | 158 | ||
| Malaria slide positive at first ANC visit | 0.651 | ||||
| Negative | 712 (86.0) | 16 (88.9) | 696 (85.9) | 1 | |
| Positive | 116 (14.0) | 2 (11.1) | 114 (14.1) | 0.63 (0.09 to 4.61) | |
| Missing | 306 | 71 | 235 | ||
ANC, antenatal care; Hb, haemoglobin.