Figure 1.
Figure 2.
Figure 3.
Characteristics of the included papers
| Study characteristic | Location | Study design | Participants (mothers) | Fetus number | % Boys | Maternal iron assessment | Neonatal/infant assessment | Iron supplementation | Key findings |
|---|---|---|---|---|---|---|---|---|---|
| Hernández-Martínez et al. [7] | Spain | Prospective longitudinal | 216 | Singleton | 49.5% | SF andTS at 10-15, 24-27, and 33-34 weeks of gestation | NBAS at 48-72 h postpartum | Systematic iron supplementation from -week 15, mean dose 48.9 mg/d | ID in first/second trimesters weakly predicted NBAS ANS scores; in third trimester, predicted NBAS motor, state organization, and robustness/endurance scores. |
| Aranda et al. [22] | Spain | Prospective longitudinal | 210 | Singleton | 47.6% | Hb levels at third trimester and delivery | NBAS at 48-72 h postpartum | Systematic iron supplementation from -week 15, mean dose 43.9 mg/d | Hemoconcentration risk in third trimester related to decreased neonatal state regulation and alertness; at delivery, to decreased state regulation and poor robustness/endurance. |
| Berglund et al. [23] | Spain | Prospective observational | 331 | Singleton | 51.4% | Ferritin, Hb, transferrin saturation at 34 weeks and at delivery | Bayley III scales of neurodevelopment at 18 months | Iron supplementation at entry (34.4% of mothers) | Maternal ID at 34 weeks associated with lower composite motor scores at 18 months; ID at delivery associated with lower cognitive, receptive, expressive, and composite language scores. |
| Mireku et al. [11] | Benin, Africa | Prospective cohort | 636 | Singleton | N/A | Hb concentration at first and second ANC visits and at delivery | Mullen scales of early learning at 1 year | Oral iron and folic acid after first ANC visit | Inverted U-shaped relationship between maternal Hband infant GM function; Hb concentration between 90 g/L and 110 g/L appears optimal for early GM function; prenatal anemia associated with higher GM scores. |
| Menon etal. [15] | India | Cohort study | 211 (second trimester), 178 (third trimester) | Singleton | N/A | Hb, SF, sTfR at second and third trimester | Infant anthropometric data and neurobe-hav¡oral data at ~3 weeks postpartum | N/A | Infants of non-anemic mothers in the second trimester were heavier, taller and had larger head circumference. Infants of non-anemic mothers in third trimester had higher orientation scores. |
| Mireku et al. [24] | Benin, Africa | Prospective cohort | 636 | Singleton | N/A | Maternal ID was assessed through blood samples taken during the prenatal period | CBSF concentration, Mullen Scales of early learning at 1 year | Oral iron and folic acid after first ANC visit | No association between prenatal ID and CBSF levels or infant cognitive and motor development at 1 year of age. However, possession score and maternal education were related to cognitive development in the infants. |
Quality assessment table
| Study | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | Total stars |
|---|---|---|---|---|---|---|---|---|---|---|
| Hernández-Martínez et al. [7] | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | 9 |
| Aranda et al. [22] | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | 9 |
| Berglund et al. [23] | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | 9 |
| Mireku et al. [11] | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | 9 |
| Menon et al. [15] | Yes | Yes | Yes | Yes | Yes | - | Yes | Yes | Yes | 8 |
| Mireku et al. [24] | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | 9 |