Cochrane · systematic review · CD004736
Daily oral iron supplementation during pregnancy
Peña‐Rosas, JP, De‐Regil, LM, Garcia‐Casal, MN, et al. · Cochrane Database of Systematic Reviews · 2015 · Cochrane Library
SoF tableOnly the outcomes this review put in its Summary of Findings table are listed (the Cochrane Handbook caps them at about seven per comparison). Its other analyses are not shown here.
Questions
22
current version
GRADE rated
22
No studies
0
Included studies
NR
No studies 0 · 0%Ungraded 0 · 0%Very low 5 · 22.7%Low 12 · 54.5%Moderate 5 · 22.7%High 0 · 0%
Ungraded means an effect was reported without a GRADE rating; it is not a gap. No studies means the review found nothing to answer the question. The six categories are a display order, not a score.
Questions and results
Current version only(Infant outcomes) Any supplements containing iron compared with same supplements without iron or no treatment/placebo (no iron or placebo) for pregnant women
Population: Pregnant women of any gestational age and parity
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Low birthweight (less than 2500 g) (ALL) (Infant outcomes) Any supplements containing iron vs same supplements without iron or no treatment/placebo (no iron or placebo) | RR 0.84 [0.69, 1.03] | 11 studies · 17613 participants | Low |
Birthweight (g) (ALL) (Infant outcomes) Any supplements containing iron vs same supplements without iron or no treatment/placebo (no iron or placebo) | no estimate extracted | 15 studies · 18590 participants | Moderate |
Preterm birth (less than 37 weeks of gestation) (ALL) (Infant outcomes) Any supplements containing iron vs same supplements without iron or no treatment/placebo (no iron or placebo) | RR 0.93 [0.84, 1.03] | 13 studies · 19286 participants | Moderate |
Neonatal death (within 28 days after delivery) (ALL) (Infant outcomes) Any supplements containing iron vs same supplements without iron or no treatment/placebo (no iron or placebo) | RR 0.91 [0.71, 1.18] | 4 studies · 16603 participants | Low |
Congenital anomalies (ALL) (Infant outcomes) Any supplements containing iron vs same supplements without iron or no treatment/placebo (no iron or placebo) | RR 0.88 [0.58, 1.33] | 4 studies · 14636 participants | Low |
(Maternal outcomes) Any supplements containing iron compared with same supplements without iron or no treatment/placebo (no iron or placebo) for pregnant women
Population: Pregnant women of any gestational age and parity
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Maternal anaemia at term (Hb less than 110 g/L at 37 weeks' gestation or more) (ALL) (Maternal outcomes) Any supplements containing iron vs same supplements without iron or no treatment/placebo (no iron or placebo) | RR 0.3 [0.19, 0.46] | 14 studies · 2199 participants | Low |
Maternal iron deficiency at term (as defined by as defined by trialists, based on any indicator of iron status at 37 weeks's gestation or more) (ALL) (Maternal outcomes) Any supplements containing iron vs same supplements without iron or no treatment/placebo (no iron or placebo) | RR 0.43 [0.27, 0.66] | 7 studies · 1256 participants | Low Downgraded: imprecision, inconsistency |
Maternal death (death while pregnant or within 42 days of termination of pregnancy) (ALL) (Maternal outcomes) Any supplements containing iron vs same supplements without iron or no treatment/placebo (no iron or placebo) | RR 0.33 [0.01, 8.19] | 2 studies · 12560 participants | Very low Downgraded: imprecision, inconsistency |
Side effects (any reported throughout the intervention period) (ALL) (Maternal outcomes) Any supplements containing iron vs same supplements without iron or no treatment/placebo (no iron or placebo) | RR 1.29 [0.83, 2.02] | 11 studies · 2423 participants | Very low Downgraded: imprecision, inconsistency |
Maternal severe anaemia at any time during second and third trimester (Hb less than 70 g/L) (ALL) (Maternal outcomes) Any supplements containing iron vs same supplements without iron or no treatment/placebo (no iron or placebo) | RR 0.22 [0.01, 3.2] | 9 studies · 2125 participants | Very low Downgraded: imprecision, inconsistency |
Infection during pregnancy (including urinary tract infections) (ALL) (Maternal outcomes) Any supplements containing iron vs same supplements without iron or no treatment/placebo (no iron or placebo) | RR 1.21 [0.33, 4.46] | 1 study · 727 participants | Low Downgraded: imprecision, inconsistency |
(Infant outcomes) Any supplements containing iron and folic acid compared with same supplements without iron nor folic acid (no iron nor folic acid or placebo) for pregnant women
Population: Pregnant women of any gestational age and parity
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Low birthweight (less than 2500 g) (ALL) (Infant outcomes) Any supplements containing iron and folic acid vs same supplements without iron nor folic acid (no iron nor folic acid or placebo) | RR 1.07 [0.31, 3.74] | 2 studies · 1311 participants | Low |
Birthweight (ALL) (Infant outcomes) Any supplements containing iron and folic acid vs same supplements without iron nor folic acid (no iron nor folic acid or placebo) | no estimate extracted | 2 studies · 1365 participants | Moderate |
Preterm birth (less than 37 weeks of gestation) (ALL) (Infant outcomes) Any supplements containing iron and folic acid vs same supplements without iron nor folic acid (no iron nor folic acid or placebo) | RR 1.55 [0.4, 6] | 3 studies · 1497 participants | Low |
Neonatal death (within 28 days after delivery) (ALL) (Infant outcomes) Any supplements containing iron and folic acid vs same supplements without iron nor folic acid (no iron nor folic acid or placebo) | RR 0.81 [0.51, 1.3] | 3 studies · 1793 participants | Low |
Congenital anomalies (ALL) (Infant outcomes) Any supplements containing iron and folic acid vs same supplements without iron nor folic acid (no iron nor folic acid or placebo) | RR 0.7 [0.35, 1.4] | 1 study · 1652 participants | Low |
(Maternal outcomes) Any supplements containing iron and folic acid compared with same supplements without iron nor folic acid (no iron nor folic acid or placebo) for pregnant women
Population: Pregnant women of any gestational age and parity
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Maternal anaemia at term (Hb less than 110 g/L at 37 weeks' gestation or more) (ALL) (Maternal outcomes) Any supplements containing iron and folic acid vs same supplements without iron nor folic acid (no iron nor folic acid or placebo) | RR 0.34 [0.21, 0.54] | 3 studies · 346 participants | Moderate |
Maternal iron deficiency at term (as defined by trialists, based on any indicator of iron status at 37 weeks' gestation or more) (ALL) (Maternal outcomes) Any supplements containing iron and folic acid vs same supplements without iron nor folic acid (no iron nor folic acid or placebo) | RR 0.24 [0.06, 0.99] | 1 study · 131 participants | Low Downgraded: imprecision |
Maternal death (death while pregnant or within 42 days of termination of pregnancy) (ALL) (Maternal outcomes) Any supplements containing iron and folic acid vs same supplements without iron nor folic acid (no iron nor folic acid or placebo) | no estimate extracted | 1 study · 131 participants | Low Downgraded: imprecision |
Side effects (any reported throughout the intervention period) (ALL) (Maternal outcomes) Any supplements containing iron and folic acid vs same supplements without iron nor folic acid (no iron nor folic acid or placebo) | RR 44.32 [2.77, 709.09] | 1 study · 456 participants | Moderate Downgraded: imprecision |
Maternal severe anaemia at any time during second and third trimester (Hb less than 70 g/L) (ALL) (Maternal outcomes) Any supplements containing iron and folic acid vs same supplements without iron nor folic acid (no iron nor folic acid or placebo) | RR 0.12 [0.02, 0.63] | 4 studies · 506 participants | Very low |
Infection during pregnancy (including urinary tract infections) (ALL) (Maternal outcomes) Any supplements containing iron and folic acid vs same supplements without iron nor folic acid (no iron nor folic acid or placebo) | RR 1 [0.15, 6.53] | 1 study · 48 participants | Very low Downgraded: imprecision |
Any supplements containing iron versus same supplements without iron or no treatment/placebo (no iron or placebo) for women during pregnancy
Population: women during pregnancy
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Low birthweight (less than 2500 g) Any supplements containing iron vs same supplements without iron or no treatment/placebo (no iron or placebo) | RR 0.81 [0.68, 0.97] | 11 studies · 8480 participants | Moderate |
Birthweight (g) Any supplements containing iron vs same supplements without iron or no treatment/placebo (no iron or placebo) | no estimate extracted | 14 studies · 9385 participants | Low |
Premature birth (less than 37 weeks of gestation) Any supplements containing iron vs same supplements without iron or no treatment/placebo (no iron or placebo) | RR 0.88 [0.77, 1.01] | 13 studies · 10148 participants | Moderate |
Neonatal death (within 28 days after delivery) Any supplements containing iron vs same supplements without iron or no treatment/placebo (no iron or placebo) | RR 0.9 [0.68, 1.19] | 4 studies · 7465 participants | Low |
Congenital anomalies Any supplements containing iron vs same supplements without iron or no treatment/placebo (no iron or placebo) | RR 0.86 [0.55, 1.35] | 3 studies · 2702 participants | Low |
Maternal anaemia at term (Hb less than 110 g/L at 37 weeks gestation or more) Any supplements containing iron vs same supplements without iron or no treatment/placebo (no iron or placebo) | RR 0.3 [0.19, 0.46] | 14 studies · 2199 participants | Moderate |
Maternal iron deficiency at term (as defined by as defined by trialists, based on any indicator of iron status at 37 weeks' gestation or more) Any supplements containing iron vs same supplements without iron or no treatment/placebo (no iron or placebo) | RR 0.43 [0.27, 0.66] | 7 studies · 1256 participants | Moderate |
Maternal death (death while pregnant or within 42 days of termination of pregnancy) Any supplements containing iron vs same supplements without iron or no treatment/placebo (no iron or placebo) | no estimate extracted | 1 study · 47 participants | Low |
Side effects (any reported throughout the intervention period) Any supplements containing iron vs same supplements without iron or no treatment/placebo (no iron or placebo) | RR 2.36 [0.96, 5.82] | 11 studies · 4418 participants | Very low |
Maternal severe anaemia at any time during 2nd or 3rd trimester (Hb less than 70 g/L) Any supplements containing iron vs same supplements without iron or no treatment/placebo (no iron or placebo) | RR 0.22 [0.01, 3.2] | 9 studies · 2125 participants | Low |
Infection during pregnancy (including urinary tract infections and others) (ALL) Any supplements containing iron vs same supplements without iron or no treatment/placebo (no iron or placebo) | RR 1.16 [0.83, 1.63] | 2 studies · 3421 participants | Low |
Any supplements containing iron and folic acid versus same supplements without iron nor folic acid (no iron nor folic acid or placebo) for women during pregnancy
Population: women during pregnancy
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Low birthweight (less than 2500 g) Any supplements containing iron and folic acid vs same supplements without iron nor folic acid (no iron nor folic acid or placebo) | RR 1.07 [0.31, 3.74] | 2 studies · 1311 participants | Very low |
Birthweight (g) Any supplements containing iron and folic acid vs same supplements without iron nor folic acid (no iron nor folic acid or placebo) | no estimate extracted | 2 studies · 1365 participants | Very low |
Premature birth (less than 37 weeks of gestation) Any supplements containing iron and folic acid vs same supplements without iron nor folic acid (no iron nor folic acid or placebo) | RR 1.55 [0.4, 6] | 3 studies · 1497 participants | Very low |
Neonatal death (within 28 days after delivery) Any supplements containing iron and folic acid vs same supplements without iron nor folic acid (no iron nor folic acid or placebo) | RR 0.81 [0.51, 1.3] | 3 studies · 1793 participants | Low |
Congenital anomalies Any supplements containing iron and folic acid vs same supplements without iron nor folic acid (no iron nor folic acid or placebo) | RR 0.7 [0.35, 1.4] | 1 study · 1652 participants | Very low |
Maternal anaemia at term (Hb less than 110 g/L, at 37 weeks' gestation or more) Any supplements containing iron and folic acid vs same supplements without iron nor folic acid (no iron nor folic acid or placebo) | RR 0.34 [0.21, 0.54] | 3 studies · 346 participants | High |
Maternal iron deficiency at term (as defined by as defined by trialists, based on any indicator of iron status, at 37 weeks' gestation or more) Any supplements containing iron and folic acid vs same supplements without iron nor folic acid (no iron nor folic acid or placebo) | RR 0.24 [0.06, 0.99] | 1 study · 131 participants | Low |
Maternal death (death while pregnant or within 42 days of termination of pregnancy) Any supplements containing iron and folic acid vs same supplements without iron nor folic acid (no iron nor folic acid or placebo) | no estimate extracted | 1 study · 131 participants | Low |
Side effects (any reported throughout the intervention period) Any supplements containing iron and folic acid vs same supplements without iron nor folic acid (no iron nor folic acid or placebo) | RR 44.32 [2.77, 709.09] | 1 study · 456 participants | Low |
Maternal severe anaemia at any time during 2nd or 3rd trimester (Hb less than 70 g/L) Any supplements containing iron and folic acid vs same supplements without iron nor folic acid (no iron nor folic acid or placebo) | RR 0.12 [0.02, 0.63] | 4 studies · 506 participants | Low |
Infection during pregnancy (including urinary tract infections and others) (ALL) Any supplements containing iron and folic acid vs same supplements without iron nor folic acid (no iron nor folic acid or placebo) | RR 1 [0.15, 6.53] | 1 study · 48 participants | Very low |