Table 1.
Description of 17 randomized controlled trials on the association between prenatal zinc supplementation and birthweight, 1984-2009
| Author and year of publication | Country | Dose | Type | Intervention Group | Control group | Mean difference (g) (95% CI) | Total sample-size | ||
|---|---|---|---|---|---|---|---|---|---|
| Mean birthweight (g) (SD) | Samplesize | Mean birthweight (g) (SD) | Sample-size | ||||||
| Goldenberg RL et al., 1995 (11) | USA | 25 mg | HIB | 3,214 (669) | 294 | 3,088 (728) | 286 | 126 (12.1, 239.9) | 580 |
| Hunt IF et al., 1985 (15) | USA | 20 mg | HIB | 3,352 (430) | 55 | 3,338 (592) | 51 | 14 (-184.3, 212.3) | 106 |
| Tamura T et al., 2003 (12) | USA | 25 mg | HIB | 3,267 (592) | 173 | 3,117 (666) | 182 | 150 (19.1, 280.9) | 355 |
| Hunt IF et al., 1984 (16) | USA | 20 mg | HIB | 3,430 (509) | 81 | 3,368 (442) | 64 | 62 (-93.0, 217.0) | 145 |
| Mahomed K et al., 1989 (17) | UK | 20 mg | HIB | 3,291 (581) | 247 | 3,319 (531) | 244 | -28 (-126.4, 70.4) | 491 |
| Simmer K et al., 1991 (18) | UK | 23 mg | HIB | 2,990 (540) | 30 | 2,820 (600) | 22 | 170 (-146.5, 486.5) | 52 |
| Robertson JS et al., 1991 (19) | UK | 62 mg | HIB | 3,264 (722) | 72 | 3,220 (871) | 62 | 44 (-229.5, 317.5) | 134 |
| Caulfield LE et al., 1999 (20) | Peru | 15 mg | CB | 3,267 (461) | 488 | 3,300 (498) | 469 | -33 (-93.9,27.9) | 957 |
| Merialdi M et al., 2004 (21) | Peru | 25 mg | CB | 3,351 (427) | 94 | 3,319 (389) | 101 | 32 (-82.9,146.9) | 195 |
| Hafez A et al., 2004 (22) | Pakistan | 20 mg | HIB | 3,023 (456) | 121 | 3,061 (444) | 121 | -38 (-151.4,75.4) | 242 |
| Christian P et al., 2003 (32) | Nepal | 25 mg | CB | 2,598 (428) | 553 | 2,652 (429) | 522 | -54 (-105.3,−2.7) | 1,075 |
| Danesh A et al., 2009 (14) | Iran | 30 mg | HIB | 2,961(498) | 42 | 2,819 (609) | 42 | 142 (-95.9,379.9) | 84 |
| Dijkhuizen MA et al., 2004 (23) | Indonesia | 25 mg | CB | 3,200 (500) | 84 | 3,150 (400) | 80 | 50 (-88.3, 188.3) | 164 |
| Saaka M et al., 2009 (24) | Ghana | 40 mg | HIB | 3,105 (490) | 272 | 3,120 (486) | 271 | -15 (-97.1, 67.1) | 543 |
| Duran CC et al., 2001 (13) | Chile | 20 mg | CB | 3,319 (460) | 249 | 3,250 (514) | 258 | 69 (-15.8, 153.8) | 507 |
| Osendarp JM et al., 2009 (25) | Bangladesh | 30 mg | CB | 2,513 (390) | 194 | 2,554 (393) | 216 | -41 (-116.9, 34.9) | 410 |
| Garg HK et al., 1993 (10) | India | 45 mg | CB | 3,000 (513) | 106 | 2,600 (541) | 62 | 400 (233.6, 566.4) | 168 |
CB=Community-based
CI=Confidence interval
HIB=Health institution-based
SD=Standard deviation