Table 2.
Characteristics of women at recruitment, by group and centre
| Characteristic | All | 1o de Maio study centre | Machava study centre | |||
|---|---|---|---|---|---|---|
| n = 4326 | n = 2749 | n = 1577 | ||||
| Selective iron* | Routine iron † | Selective iron* | Routine iron † | Selective iron* | Routine iron † | |
| n = 2142 | n = 2184 | n = 1366 | n = 1383 | n = 776 | n = 801 | |
| Maternal age (years), mean (SD) ‡ | 24.8 (5.5) | 24.7 (5.5) | 24.5 (5.5) | 24.2 (5.4) | 25.2 (5.4) | 25.4 (5.5) |
| Maternal age, n (%) | ||||||
| < 20 | 357 (17) | 390 (18) | 247 (18) | 270 (20) | 110 (14) | 120 (15) |
| 20–24 | 859 (40) | 842 (39) | 566 (41) | 559 (40) | 293 (38) | 283 (35) |
| 25–29 | 502 (23) | 510 (23) | 297 (22) | 301 (22) | 205 (26) | 209 (26) |
| 30–34 | 257 (12) | 296 (13) | 145 (11) | 167 (12) | 112 (14) | 129 (16) |
| ≥35 | 146 (7) | 132 (6) | 98 (7) | 73 (5) | 48 (7) | 59 (8) |
| Missing | 21 (1) | 14 (1) | 13 (1) | 13 (1) | 8 (1) | 1 (0) |
| Gestational age (weeks), mean (SD) ‡ | 10.4 (6.0) | 10.2 (5.9) | 9.9 (5.8) | 9.6 (5.6) | 11.2 (6.1) | 11.2 (6.4) |
| Measurement of gestational age, n (%) | ||||||
| Last menstruation | 1850 (86) | 1900 (87) | 1138 (83) | 1165 (84) | 712 (92) | 735 (92) |
| Uterine height | 284 (13) | 272 (12) | 222 (16) | 211 (15) | 62 (8) | 61 (7) |
| Missing | 8 (1) | 12 (1) | 6 (1) | 7 (1) | 2 (0) | 5 (1) |
| Previous abortions, n (%) | ||||||
| Yes | 274 (13) | 298 (14) | 165 (12) | 180 (13) | 109 (14) | 118 (15) |
| No | 1861 (87) | 1881 (86) | 1197 (88) | 1201 (87) | 664 (86) | 680 (85) |
| Missing | 7 (0) | 5 (0) | 4 (0) | 2 (0) | 3 (0) | 3 (0) |
| Previous stillbirths, n (%) | ||||||
| Yes | 172 (8) | 176 (8) | 79 (6) | 94 (7) | 93 (12) | 82 (10) |
| No | 1962 (92) | 2002 (92) | 1284 (94) | 1287 (93) | 678 (87) | 715 (89) |
| Missing | 8 (0) | 6 (0) | 3 (0) | 2 (0) | 5 (1) | 4 (1) |
| Number of previous deliveries, n (%) | ||||||
| None | 631 (30) | 699 (32) | 429 (31) | 476 (34) | 202 (26) | 223 (28) |
| One | 671 (31) | 658 (30) | 434 (32) | 436 (32) | 237 (31) | 222 (28) |
| Two | 399 (19) | 397 (18) | 237 (17) | 236 (17) | 162 (21) | 161 (20) |
| Three or more | 435 (20) | 425 (20) | 262 (19) | 233 (17) | 173 (22) | 192 (24) |
| Missing | 6 (0) | 5 (0) | 4 (1) | 2 (0) | 2 (0) | 3 (0) |
| Number of previous live births, n (%) | ||||||
| None | 652 (30) | 719 (33) | 443 (32) | 493 (36) | 209 (27) | 226 (28) |
| One | 665 (31) | 658 (30) | 430 (32) | 434 (31) | 235 (30) | 224 (28) |
| Two | 402 (19) | 391 (18) | 240 (18) | 234 (17) | 162 (21) | 157 (20) |
| Three or more | 418 (20) | 411 (19) | 249 (18) | 220 (16) | 169 (22) | 191 (24) |
| Missing | 5 (0) | 5 (0) | 4 (0) | 2 (0) | 1 (0) | 3 (0) |
| HIV status, n (%) | ||||||
| Positive | 446 (21) | 428 (20) | 271 (20) | 251 (18) | 175 (23) | 177 (22) |
| Negative | 1696 (79) | 1756 (80) | 1095 (80) | 1132 (82) | 601 (77) | 624 (78) |
| Haemoglobin by HemoCue (g/dL), mean (SD) ‡ | 9.6 (1.7) | 9.6 (1.7) | 9.7 (1.7) | |||
| Haemoglobin by HemoCue (g/dL), n (%) | ||||||
| < 7.0 | 141 (7) | 102 (8) | 39 (5) | |||
| 7.0–8.90 | 535 (25) | 343 (25) | 192 (25) | |||
| 9.0–9.90 | 512 (24) | 336 (25) | 176 (23) | |||
| 10.0–10‐90 | 462 (22) | 294 (22) | 168 (22) | |||
| 11.0–11.90 | 298 (14) | 168 (12) | 130 (17) | |||
| ≥12.0 | 174 (8) | 110 (8) | 64 (8) | |||
| Not measured | 20 (1) | 13 (1) | 7 (1) | |||
| Iron + folic acid given, n (%) | ||||||
| Yes | 708 (33) | 2164 (99) | 464 (34) | 1368 (99) | 244 (32) | 796 (99) |
| No | 1421 (66) | 14 (1) | 892 (65) | 11 (1) | 529 (68) | 3 (0) |
| Missing | 13 (1) | 6 (0) | 10 (1) | 4 (0) | 3 (0) | 2 (0) |
| Only folic acid given, n (%) | ||||||
| Yes | 1426 (67) | 15 (1) | 894 (65) | 10 (1) | 532 (69) | 5 (1) |
| No | 701 (33) | 2159 (99) | 460 (34) | 1367 (99) | 241 (31) | 792 (99) |
| Missing | 15 (0) | 10 (0) | 12 (1) | 6 (0) | 3 (0) | 4 (0) |
| Fever during current pregnancy, n (%) | ||||||
| Yes | 550 (26) | 527 (24) | 405 (30) | 377 (27) | 145 (19) | 150 (19) |
| Headache during current pregnancy, n (%) | ||||||
| Yes | 917 (43) | 944 (43) | 634 (46) | 682 (49) | 283 (37) | 262 (33) |
| Cold/chills during current pregnancy, n (%) | ||||||
| Yes | 412 (19) | 406 (19) | 299 (22) | 298 (22) | 113 (15) | 108 (14) |
| Vomit/nausea during current pregnancy, n (%) | ||||||
| Yes | 612 (29) | 605 (28) | 434 (32) | 444 (32) | 178 (23) | 161 (20) |
| Body aches during current pregnancy, n (%) | ||||||
| Yes | 487 (23) | 488 (22) | 361 (26) | 379 (27) | 126 (16) | 109 (14) |
| Malaria prophylaxis during current pregnancy, n (%) | ||||||
| Yes | 856 (40) | 923 (42) | 481 (35) | 499 (36) | 375 (48) | 424 (53) |
| Malaria during current pregnancy, n (%) | ||||||
| Yes | 125 (6) | 135 (6) | 84 (6) | 86 (6) | 41 (5) | 49 (6) |
| Had malaria test, n (%) | ||||||
| Yes | 159 (7) | 164 (8) | 107 (8) | 107 (8) | 52 (7) | 57 (7) |
*Policy 2: daily intake of 400 μg of folic acid and received iron (120 mg) if their haemoglobin was <9 g/dL. †Policy 1: daily intake of 60 mg ferrous sulphate plus 400 μg of folic acid. ‡Missing data excluded when calculating the mean and standard deviation: maternal age (Selective n = 21, Routine n = 14); gestational age (Selective n = 8, Routine n = 12); haemoglobin (Selective n = 20).