TABLE 3.
The effect of prenatal nutritional supplements on the risk of severely inadequate, inadequate, and excessive GWG1
| Intervention | ||
|---|---|---|
| Outcome | MMSs | Small-quantity LNSs |
| Severely inadequate | ||
| Studies, n | 14 | 4 |
| Participants, total n | 45,507 | 6237 |
| Participants, n by intervention/control arms | 22,940/22,567 | 2335/3902 |
| RR (95% CI), fixed-effects | 0.971 (0.956, 0.987) | 0.952 (0.903, 1.005) |
| RR (95% CI), random-effects | 0.959 (0.922, 0.997) | 0.935 (0.829, 1.055) |
| I2,2 % | 57.6 | 71.1 |
| P-heterogeneity | <0.01 | 0.02 |
| Inadequate | ||
| Studies, n | 14 | 4 |
| Participants, total n | 45,507 | 6237 |
| Participants, n by intervention/control arms | 22,940/22,567 | 2335/3902 |
| RR (95% CI), fixed-effects | 0.986 (0.978, 0.995) | 0.992 (0.962, 1.022) |
| RR (95% CI), random-effects | 0.982 (0.963, 1.002) | 0.976 (0.927, 1.028) |
| I2,2 % | 48.4 | 46.8 |
| P-heterogeneity | 0.02 | 0.13 |
| Excessive | ||
| Studies, n | 14 | 4 |
| Participants, total n | 45,507 | 6237 |
| Participants, n by intervention/control arms | 22,940/22,567 | 2335/3902 |
| RR (95% CI), fixed-effects | 1.042 (0.975, 1.113) | 1.131 (0.970, 1.318) |
| RR (95% CI), random-effects | 1.032 (0.944, 1.127) | 1.127 (0.946, 1.342) |
| I2,2 % | 18.3 | 15.6 |
| P-heterogeneity | 0.25 | 0.31 |
The percentage adequacy of GWG was calculated by dividing the actual GWG at the last weight measure during pregnancy by the recommended GWG according to the Institute of Medicine (IOM) 2009 guideline, multiplied by 100. Severely inadequate GWG was defined as percentage adequacy <70%, inadequate GWG as percentage adequacy <90%, and excessive GWG as percentage adequacy >125%. GWG, gestational weight gain; LNS, lipid-based nutrient supplement; MMS, multiple micronutrient supplement; RR, risk ratio.
I2 is a statistic index used to assess heterogeneity across trials, with thresholds of <30%, 30–60%, and >60% considered low, moderate, and high heterogeneity, respectively.