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

Pregnancy and Childbirth2 versionsAMSTAR 2: not assessed
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

Show all 2 versions

(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
5 questions
OutcomeEffectEvidenceStatus / 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 participantsLow
Birthweight (g) (ALL)
(Infant outcomes) Any supplements containing iron vs same supplements without iron or no treatment/placebo (no iron or placebo)
no estimate extracted15 studies · 18590 participantsModerate
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 participantsModerate
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 participantsLow
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 participantsLow

(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
6 questions
OutcomeEffectEvidenceStatus / 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 participantsLow
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 participantsLow
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 participantsVery 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 participantsVery 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 participantsVery 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 participantsLow
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
5 questions
OutcomeEffectEvidenceStatus / 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 participantsLow
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 extracted2 studies · 1365 participantsModerate
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 participantsLow
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 participantsLow
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 participantsLow

(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
6 questions
OutcomeEffectEvidenceStatus / 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 participantsModerate
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 participantsLow
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 extracted1 study · 131 participantsLow
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 participantsModerate
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 participantsVery 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 participantsVery low
Downgraded: imprecision