Table 1.
Summary of study characteristics.
| Author, year, location | Study design | Participant characteristics | Methods and timing of data collection | Biomarker analyses | Biomarkers | Correlation r (95%CI)/mean | NOS quality score |
|---|---|---|---|---|---|---|---|
| Adams et al. [21], 1981, Nepal | Cross-sectional | Sample size: 151 Maternal age (a): NR Malaria setting: Yes Iron supplementation: NR |
Maternal venous blood at delivery Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Cyanmethemoglobin method | Maternal: Hb Newborn: Hb |
r = −0.06 (−0.22, 0.10) | 3 |
| Agrawal et al. [22] 1983, India | Cross-sectional | Sample size: 51 Maternal age (a) : NR Malaria setting: Yes Iron supplementation: NR |
Maternal venous blood at delivery Umbilical cord (placental end) at delivery Inflammation biomarkers: NR Factors adjusted:Groups compared had no racial, cultural and environmental differences. |
NR | Maternal: Serum iron Newborn: Serum iron |
r = 0.53 (0.30, 0.70) | 5 |
| Akhter et al. [23] 2010, Bangladesh | Cross-sectional | Sample size: 50 Maternal age (a): NR Malaria setting: Yes Iron supplementation: NR |
Maternal antecubital blood postpartum Umbilical cord (placental end) at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Cyanmethemoglobin for Hb, ELISA for ferritin | Maternal: Ferritin Newborn: Ferritin |
r = −0.94 (−0.97, −0.90) | 4 |
| Maternal: Hb Newborn: Ferritin |
r = 0.48 (0.23, 0.67) | ||||||
| Altinkaynak et al., [41] 1984, Turkey | Cross-sectional | Sample size: 52 Maternal age (a): 26±5.3 Malaria setting: Yes Iron supplementation: Some women |
Maternal peripheral blood at delivery Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Ferritin enzymatic testing kits from Medix Biotech | Maternal: Ferritin Newborn: Ferritin |
r = 0.68 (0.49, 0.80) | 4 |
| Awadallah et al. [75], 2004, Jordan | Prospective cohort | Sample size: 186 Maternal age (a): 27±4.9/ 17–45 Malaria setting: No Iron supplementation: All women |
Maternal blood at delivery Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Haematology cell counter | Maternal: Hb Newborn: Hb |
Maternal (anaemic 10.2 ± 0.6, non-anaemic 12.2 ± 1.2 g/dL); newborn (anaemic: 15.1 ± 2.0; non-anaemic 15.8 ± 2.3 g/dL) | 7 |
| Babay et al. [42] 2002, Saudi Arabia | Cros-sectional | Sample size: 82 Maternal age (a): 26.9 ± 5.79/ 16–40 Malaria setting: Yes Iron supplementation: None |
Maternal venous blood at delivery Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Radial immunodiffusion for Tf, Coulter Counter ZF6 for haematologic parameters | Maternal: Tf Newborn: Tf |
r = 0.40 (0.20, 0.57) | 6 |
| Maternal: Hb Newborn: Hb |
r = 0.14 (−0.08, 0.35) | ||||||
| Maternal: MCHb Newborn: MCHb |
r = 0.66 (0.52, 0.77) | ||||||
| Maternal: MCV Newborn: MCV |
r = 0.36 (0.16, 0.54) | ||||||
| Basu et al. [76] 2016, India | Prospective cohort | Sample size: 45 Maternal age (a): Anaemic: 25.3 ± 3.7; Non-anaemic: 26.3 ± 3.4 Malaria setting: Yes Iron supplementation: NR |
Maternal peripheral blood postpartum Umbilical cord (placental end) at delivery Inflammation biomarkers: NR Factors_adjusted: NR |
Auto analyser for serum iron, ferritin, TIBC, Tf Sat. ELISA for hepcidin | Maternal: Ferritin Newborn: Ferritin, Hepcidin, Serum iron, Tf Sat, TIBC, Hb |
r = 0.94 (0.89, 0.97), 0.46 (0.19, 0.66), 0.91 (0.84, 0.95), 0.88 (0.69, 0.90), −0.81 (−0.89, −0.68), 0.89 (0.80, 0.94) | 5 |
| Maternal: Hepcidin Newborn: Ferritin, Hepcidin, Serum iron, Tf Sat, TIBC, Hb |
r = 0.37 (0.09, 0.60), 0.72 (0.54, 0.83), 0.37 (0.09, 0.60), 0.33 (0.04, 0.57), −0.24 (−0.50, 0.06), 0.39 (0.11, 0.61) | ||||||
| Maternal: Serum iron Newborn Ferritin, Hepcidin, Serum iron, Tf Sat, TIBC, Hb |
r = 0.91 ( 0.78, 0.93), 0.401 (0.12, 0.62), 0.87 (0.78, 0.93), 0.87 (0.77, 0.92), −0.79 (−0.88, −0.65), 0.81 (0.67, 0.89) | ||||||
| Maternal: Tf Sat Newborn: Ferritin, Hepcidin, serum iron, Tf Sat, TIBC, Hb |
r = 0.90 (0.82, 0.94), 0.35 (0.06, 0.58), 0.81 (0.68, 0.89), 0.84 (0.73, 0.91), 0.80 (0.66, 0.89), 0.84 (0.73, 0.91) | ||||||
| Maternal: TIBC Newborn: Ferritin, Serum iron, Tf Sat, TIBC, ZPP, Hb |
r = −0.84 (−0.91, −0.73), −0.75 (−0.86, −0.59), −0.79 (−0.88, −0.64), 0.80 (0.67, 0.89), −0.404 (−0.62, −0.13), −0.838 (−0.91, −0.72) | ||||||
| Maternal: Hb Newborn: Ferritin, Hepcidin , Serum iron, Tf Sat, TIBC, Hb |
r = 0.92 (0.85, 0.95), 0.556 (0.31, 0.73), 0.88 (0.80, 0.93), 0.87 (0.77, 0.93), −0.78 (−0.87, −0.63), 0.83 (0.70, 0.90) | ||||||
| Best et al. [77] 2016, USA | Prospective cohort | Sample size: 255 Maternal age (a): 17.1 ± 1.1 Malaria setting: No Iron supplementation: NR |
Maternal venous blood at delivery Umbilical cord blood at delivery Inflammation biomarkers: IL-6 Factors adjusted: NR |
NR | Maternal: Ferritin Newborn: Ferritin |
r = 0.37 (0.26, 0.47) | 6 |
| Maternal: Hepcidin Newborn: Hepcidin |
r = 0.32 (0.21, 0.43) | ||||||
| Maternal: sTfR Newborn: sTfR |
r = 0.23 (0.11, 0.34) | ||||||
| Bratlid et al. [43] 1980, Norway | Cross-sectional | Sample size: 54 Maternal age (a): NR Malaria setting: No Iron supplementation: NR |
Maternal venous blood at delivery Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Radioimmunoassay for ferritin; method for Hb NR | Maternal: Ferritin Newborn: Ferritin |
r = 0.18 (−0.09, 0.43) | 3 |
| Maternal: Hb Newborn: Hb |
r = 0.33 (0.07, 0.55) | ||||||
| Butte et al. [44] 1982, USA | Cross-sectional | Sample size: 28 Maternal age (a): 16–33 Malaria setting: No Iron supplementation: NR |
Maternal venous blood postpartum Umbilical cord blood at delivery Inflammation biomarkers: None Factors adjusted: NR |
NR | Maternal: Ferritin Newborn: Ferritin |
r = −0.002 (−0.37, 0.37) | 3 |
| Celada et al. [45] Germany | Cross-sectional | Sample size: 64 Maternal age (a): 23±4/ 19–31 Malaria setting: No Iron supplementation: All women |
Maternal venous blood postpartum Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Radioimmunoassay for ferritin | Maternal: Ferritin Newborn: Ferritin |
r = 0.07 (−0.18, 0.31) | 4 |
| Custodio et al. [46] 2005, Portugal | Cross-sectional | Sample size: NR Maternal age (a): 15–39 Malaria setting: No Iron supplementation: NR |
Maternal blood postpartum Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Energy dispersive X-ray fluorescence spectrometry | Maternal: Serum iron Newborn: Serum iron |
r = 0.51 (0.31, 0.67) | 2 |
| Daouda et al. [24] 1991, Niger | Cross-sectional | Sample size: 364 Maternal age (a): 26.0 ± 6.4/ 15–47 Malaria setting: Yes Iron supplementation: None |
Maternal venous blood at delivery Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
ELISA for ferritin. Microcentrifugation for Ht | Maternal: Ferritin Newborn: Ferritin Maternal: Ht Newborn: Ht |
Maternal mean 41.8 ± 66.1 ug/L; cord mean 127.3 ± 62.9 ug/L | 6 |
| Maternal mean 32.8 ± 5.1%; cord mean 43.0 ± 5.7% | |||||||
| Dapper et al. [47] 2006, Nigeria | Cross-sectional | Sample size: 30 Maternal age (a): 19–40 Malaria setting: Yes Iron supplementation: NR |
Maternal venous blood postpartum Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Microcentrifugation for Ht. Cyanmethaemoglobin for Hb. Manual counting chamber for blood cell counts | Maternal: Hb Newborn: Hb |
r = 0.42 (0.08, 0.68) | 4 |
| Maternal: Ht Newborn: Ht |
r = 0.22 (−0.16, 0.53) | ||||||
| Maternal: MCHb Newborn: MCHb |
r = −0.05 (−0.40, 0.32) | ||||||
| Maternal: MCV Newborn: MCV |
r = 0.22 (−0.15, 0.54) | ||||||
| De Sa, [25] 2015, Brazil | Cross-sectional | Sample size: 54 Maternal age (a): 24.5 ± 4.1/ 20–38 Malaria setting: Yes Iron supplementation: NR |
Maternal venous blood at delivery Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Automatic device for haematologic analyses; ELISA for ferritin | Maternal: Ferritin Newborn: Ferritin |
Maternal mean: 9.6 ± 8.0 ug/L, cord mean: 122.9 ± 62.4 ug/L | 4 |
| Maternal: Hb Newborn: Ht |
r = 0.47 (0.23, 0.66) | ||||||
| Devi et al., [78] 1989, India | Prospective cohort | Sample size: 165 Maternal age (a): 26.8/ 18–42 Malaria setting: Yes Iron supplementation: All women |
Maternal blood postpartum Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Cyanomethaemoglobin method for Hb | Maternal: Hb Newborn: Hb |
r = 0.02 (−0.13, 0.18) | 5 |
| Ek et al., [26] 1982, Norway | Cross-sectional | Sample size: 139 Maternal age (a): NR Malaria setting: No Iron supplementation: All women |
Maternal venous blood postpartum Neonatal capillary blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
NR | Maternal: Hb Newborn: Hb |
r = 0.17 (0.004, 0.33) | 6 |
| El Guindi et al. [84] 2004, Guyana | Retrospective cohort | Sample size: 222 Maternal age (a): Anaemic: 24.9/ non-anaemic 26.7 Malaria setting: Yes Iron supplementation: NR |
Timing of maternal blood collection NR Neonatal blood source NR, collected at delivery Inflammation biomarkers: CRP Factors adjusted: NR |
NR | Maternal: hb Newborn: hb |
anaemic mothers 6.92 g/100 ml; non-anaemic mothers 11.54 g/100 ml; newborns of anaemic mothers 15.04 g/100 ml, newborns of non-anaemic mothers 15.75 g/100ml | 6 |
| El-Farrash et al. [27] 2012, Egypt | Cross-sectional | Sample size: 80 Maternal age (a): Anaemic: 25.2 ± 3.3; Non-anaemic: 26.8 ± 5.0 Malaria setting: No Iron supplementation: None |
Maternal blood postpartum Umbilical cord (placental end) at delivery Inflammation biomarkers: CRP Factors adjusted: CRP |
ELISA for ferritin; Commercial kit for TIBC; Hitachi 917 analyser for serum iron; haematologic indices by Coulter Counter GEN-S | Maternal: Ferritin Newborn: Ferritin, Serum iron, Tf Sat, TIBC, Hb, MCHb, MCV, |
r = 0.47 (0.28, 0.62), 0.39 (0.19, 0.56), 0.430 (0.21, 0.87), −0.39 (−0.56, −0.18), 0.67 (0.52, 0.77), 0.496 (0.31, 0.65), 0.39 (0.19, 0.56) | 5 |
| Maternal: Serum iron Newborn: Ferritin, Serum iron, Tf Sat, TIBC, Hb, MCHb, MCV |
r = 0.345 (0.25, 0.61), 0.45 (0.25, 0.61), 0.44 (0.25, 0.60), −0.36 (−0.54, −0.15), 0.58 (0.42, 0.71), 0.348 (0.14, 0.53), 0.327 (0.12, 0.51) | ||||||
| Maternal: Hb Newborn: Serum iron, Tf Sat, TIBC, Hb, MCV, |
r = 0.48 (0.29, 0.63), 0.51 (0.32, 0.65), −0.46 (−0.62, −0.27), 0.76 (0.65, 0.84), 0.55 (0.37, 0.69), | ||||||
| Erdem et al. [48] 2002, Turkey | Cross-sectional | Sample size: 44 Maternal age (a): NR Malaria setting: Yes Iron supplementation: Unclear |
Maternal blood at delivery Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: Controls matched for age, parity and gestational age |
Automated cytometer for Hb. Chemiluminescence technique for ferritin | Maternal: Ferritin Newborn: Ferritin |
r = 0.52 (0.27, 0.71) | 7 |
| Maternal: Hb Newborn: Hb |
Maternal mean: (anaemic 8.72±0.22; non-anaemic 16.11±0.39); cord mean: (anaemic 11.74±0.24; non-anaemic 16.57± | ||||||
| Esmailnasab et al. [49] 2012, Iran | Cross-sectional | Sample size: 604 Maternal age (a): NR Malaria setting: Yes Iron supplementation: NR |
Timing of maternal blood collection NR Timing of umbilical cord collection NR Inflammation biomarkers: NR Factors adjusted: NR |
Cell counter machine | Maternal: Hb Newborn: Hb |
r = 0.14 (0.06, 0.22) | 3 |
| Garcia-Valdes et al. [79] 2015, Spain | Prospective cohort | Sample size: 308 Maternal age (a): Control 30.8 ± 4.3, Overweight 31.8 ± 4.5, Obese = 29.0 ± 4.6 Malaria setting: No Iron supplementation: Some women |
Maternal blood at delivery Umbilical cord blood at delivery Inflammation biomarkers: CRP Factors adjusted: Inflammation |
ELISA | Maternal: Hepcidin Newborn: Hepcidin |
r = 0.70 (0.64, 0.75) | 6 |
| Gaspar et al. [28] 1993, Spain | Cross-sectional | Sample size: 157 Maternal age (a): 29.0 ± 0.5 Malaria setting: No Iron supplementation: NR |
Maternal blood at delivery Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Automated haematology cell counter | Maternal: Hb Newborn: Hb, Ht |
r = 0.36 (0.22, 0.49), 0.30 (0.15, 0.44) | 5 |
| Maternal: Ht Newborn: Hb, Ht |
r = 0.37 (0.23, 0.50), 0.33 (0.18, 0.46) | ||||||
| Huang et al. [50] 2017, Taiwan | Cross-sectional | Sample size: 150 Maternal age (a): 28.1 ± 5.2 Malaria setting: No Iron supplementation: NR |
Maternal venous blood at delivery Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Plasma mass spectrometry | Maternal: Serum iron Newborn: Serum iron |
r = 0.17 (95%CI 0.01, 0.32) | 5 |
| Hussain et al. [51] 1977, UK | Cross-sectional | Sample size: 51 Maternal age (a): 17–38 Malaria setting: No Iron supplementation: NR |
Maternal blood at delivery Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Immunoradiometric assay | Maternal: Ferritin Newborn: Ferritin |
r = 0.30 (0.03, 0.53) | 6 |
| Jaime-Perez et al. [52] 2005, Mexico | Cross-sectional | Sample size: 201 Maternal age (a): 23.0 ± 6.5 Malaria setting: Yes Iron supplementation: NR |
Maternal blood at delivery Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Automated blood cell counter | Maternal: Hb Newborn: Hb |
Newborns of anaemic 157±17 g/L and non-anaemic 159±14 g/L mothers | 7 |
| Jariwala et al. [53] 2014, India | Cross-sectional | Sample size: 42 Maternal age (a): NR Malaria setting: Yes Iron supplementation: NR |
Maternal venous blood at delivery Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
NR | Maternal: Serum iron Newborn: Serum iron |
r = 0.39 (0.09, 0.62) | 4 |
| Kaneshige et al. [80] 1981, Japan | Prospective cohort | Sample size: 80 Maternal age (a): 20–30 Malaria setting: No Iron supplementation: NR |
Maternal blood at delivery Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
NR | Maternal: Ferritin Newborn: Ferritin |
r = 0.75 (0.64, 0.84) | 7 |
| Maternal: Serum iron Newborn: Serum iron |
r = 0.52 (0.22, 0.73) | ||||||
| Katoh et al. [54], 1984, Japan | Cross-sectional | Sample size: NR Maternal age (a): NR Malaria setting: No Iron supplementation: NR |
Maternal blood at delivery Neonatal blood source unclear at delivery Inflammation biomarkers: NR Factors adjusted:NR |
NR | Maternal: Serum iron Newborn: Serum iron, Hb |
r = 0.64 (0.37, 0.81), 0.71 (0.47, 0.85) | 4 |
| Maternal: Hb Newborn: Serum iron, Hb |
r = 0.22 (−0.14, 0.52), 0.68 (0.43, 0.83) | ||||||
| Koc et al. [55] 2006, Turkey | Cross-sectional | Sample size: 188 Maternal age (a): 27±5.8 Malaria setting: Yes Iron supplementation: NR |
Maternal venous blood at delivery Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Colorimetric method for serum iron, TIBC | Maternal: Serum iron Newborn: Serum iron |
r = 0.13 (−0.02, 0.26) | 4 |
| Maternal: Tf Sat Newborn: Tf Sat |
r = 0.11 (−0.04, 0.24) | ||||||
| Maternal: TIBC Newborn: TIBC |
r = 0.20 (0.06, 0.33) | ||||||
| Kulik-Rechberger et al. [56] 2016, Poland | Cross-sectional | Sample size: 44 Maternal age (a): 27.8 ± 5.5/ 18–42 Malaria setting: No Iron supplementation: NR |
Maternal peripheral blood at delivery Umbilical cord blood at delivery Inflammation biomarkers: CRP Factors adjusted: NR |
ELISA for sTfR and automated analyser for Hb | Maternal: Hb Newborn: sTfR |
r = 0.36 (0.07, 0.59) | 5 |
| Kumar et al. [57] 2008, India | Cross-sectional | Sample size: 75 Maternal age (a): NR Malaria setting: Yes Iron supplementation: NR |
Maternal blood at delivery Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Cyanmethaemoglobin method for Hb. Atomic absorption spectroscopy for serum iron. ELISA for ferritin | Maternal: Ferritin Newborn: Ferritin, Serum iron, Hb |
r = 0.44 (0.24, 0.61), 0.45 (0.24, 0.61), 0.49 (0.29, 0.64) | 7 |
| Maternal: Serum iron Newborn: Serum iron |
r = 0.76 (0.65, 0.84) | ||||||
| Maternal: Hb Newborn: Hb |
r = 0.62 (0.45, 0.74) | ||||||
| Lao et al. [58] 1991, China | Cross-sectional | Sample size: 96 Maternal age (a): 27.6 ± 3.6 Malaria setting: Yes Iron supplementation: NR |
Maternal blood at delivery Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted:NR |
Dye-binding analysis for serum iron and TIBC; Radioimmunoassay for ferritin; automated Technicon CBC counter for haematologic indices nalysis for serum iron and TIBC. Radioimmunoassay for ferritin |
Maternal: Ferritin Newborn: Ferritin, Serum iron, TIBC |
r = 0.10 (−0.10, 0.29), 0.18 (−0.02, 0.37), 0.22 (0.02, 0.40) | 3 |
| Maternal: Serum iron Newborn: Ferritin, Serum iron, TIBC |
r = 0.126 (−0.07, 0.34), 0.14 (−0.07, 0.33), 0.04 (−0.17, 0.25) | ||||||
| Maternal: TIBC Newborn: Ferritin, Serum iron, TIBC |
r = 0.10 (−0.10, 0.29), 0.18 (−0.02, 0.37), 0.20 (0.06, 0.33) | ||||||
| Maternal: Hb Newborn: Ferritin, Serum iron, TIBC |
r = 0.03 (−0.17, 0.23), 0.14 (−0.07, 0.33), 0.03 (−0.17, −0.23) | ||||||
| Maternal: Ht Newborn: Ferritin, Serum iron, TIBC |
r = −0.034 (−0.17, 0.23), 0.075 (−0.13, 0.27) | ||||||
| Maternal: MCHb Newborn: Ferritin, Serum iron, TIBC |
r = 0.056 (−0.15, 0.25), 0.248 (0.05, 0.43), 0.087 (−0.12, 0.28) | ||||||
| Maternal: MCV Newborn: Ferritin, Serum iron, TIBC |
r = 0.001(−0.20, 0.20), 0.238 (0.04, 0.42), 0.077 (−0.13, 0.27) | ||||||
| Lee et al. [81] 2016, USA | Prospective cohort | Sample size: 255 Maternal age (a): NR Malaria setting: No Iron supplementation: NR |
Timing of maternal blood sampling NR Umbilical cord blood at delivery Inflammation biomarkers: CRP, IL-6 Factors adjusted: NR |
Automated haematology analyser or HemoCue system for Hb; ELISA for sTfR, ferritin; method for hepcidin NR | Maternal: Ferritin Newborn: Ferritin |
r = 0.08 (−0.04, 0.20) | 6 |
| Maternal: Hepcidin Newborn: Hepcidin |
r = 0.13 (0.0073, 0.25) | ||||||
| Maternal: sTfR Newborn: sTfR |
r = 0.18 (0.06, 0.30) | ||||||
| Maternal: Hb Newborn: Hb |
r = −0.08 (−0.20, 0.04) | ||||||
| MacPhail et al. [59] 1980, South Africa | Cross-sectional | Sample size: 103 Maternal age (a): 24.7/16–39 Malaria setting: Yes Iron supplementation: NR |
Maternal venous blood at delivery Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Cyanomethaemoglobin method for Hb; Colorimetric chromogen for serum iron; radioimmunoassay for ferritin;, coated charcoal assay for unsaturated iron-binding capacity | Maternal: Ferritin Newborn: Ferritin, Serum iron, Tf Sat, TIBC |
r = 0.21 (0.02, 0.39), −0.19 (−0.37, 0.003), −0.11 (0.02, 0.25), 0.20 (0.005, 0.38) | 3 |
| Maternal: Serum iron Newborn: Ferritin, Serum iron, Tf Sat, TIBC |
r = 0.07 (0.02, 0.39), 0.21 (0.02, 0.39), 0.18 (−0.02, 0.36) 0.07 (−0.13, 0.26) |
||||||
| Maternal: Tf Sat Newborn: Ferritin, Serum iron, Tf Sat, TIBC |
r = 0.14 (−0.06, 0.32), 0.09 (−0.11, 0.28), 0.10 (−0.10, 0.29), 0.02 (−0.17, 0.21) | ||||||
| Maternal: TIBC Newborn: Ferritin, Serum iron, Tf Sat, TIBC |
r = 0.18 (−0.01, 0.36), 0.11 (−0.09, 0.30), 0.02 (−0.17, 0.21), 0.10 (−0.10, 0.29) | ||||||
| Maternal: Hb Newborn: Hb |
r = 0.40 (0.22, 0.55) | ||||||
| Malcolm et al. [60] 1973, Papua New Guinea | Cross-sectional | Sample size: 98 Maternal age (a): NR Malaria setting: Yes Iron supplementation: NR |
Maternal blood postpartum Umbilical cord blood at delivery Inflammation biomarkers: IgM, IgA Factors adjusted: NR |
EEL colorimetry | Maternal: Hb Newborn: Hb |
r = 0.32 (0.13, 0.49) | 2 |
| Mezdoud et al. [29] 2017, Algeria | Cross-sectional | Sample size: 97 Maternal age (a): 31.7 ± 4.7/ 22–42 Malaria setting: No Iron supplementation: NR |
Maternal venous blood at delivery Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Automated counter for Hb and Ht. Colorimetric method for serum iron. ELISA for ferritin | Maternal: Serum iron Newborn: Serum iron |
r = 0.39 (0.21, 0.55) | 4 |
| Maternal: Tf Sat Newborn: Tf Sat |
r = 0.26 (0.06, 0.44) | ||||||
| Maternal: TIBC Newborn: TIBC |
r = 0.20 (−0.0005, 0.38) | ||||||
| Maternal: Hb Newborn: Hb |
r = 0.22 (0.22, 0.02, 0.40) | ||||||
| Maternal: Ht Newborn: Ht |
r = 0.60 (0.46, 0.71) | ||||||
| Milman et al. [62] 1987, Denmark | Cross-sectional | Sample size: 85 Maternal age (a): Median: 27/ 15–38 Malaria setting: No Iron supplementation: NR |
Maternal venous blood at delivery Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Coulter-S for Hb. Radioimmunoassay for ferritin. | Maternal: Ferritin Newborn: Ferritin |
r = 0.36 (0.16, 0.53) | 5 |
| Maternal: Hb Newborn: Ferritin |
r = −0.31 (−0.49, −0.10) | ||||||
| Milman et al. [61] 1988, Denmark | Cross-sectional | Sample size: 78 Maternal age (a): Median: 27/ 16–38 Malaria setting: No Iron supplementation: NR |
Maternal venous blood at delivery Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Haematofluorometry | Maternal: ZPP Newborn: ZPP |
r = 0.04 (−0.18, 0.26) | 3 |
| Montemagno et al. [63] 1995, UK | Cross-sectional | Sample size: 64 Maternal age (a): NR Malaria setting: No Fe supplementation: NR |
Maternal blood at delivery Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Coulter cell ounter | Maternal: Hb Newborn: Hb |
r = 0.22 (−0.03, 0.44) | 4 |
| Maternal: MCV Newborn: MCV |
r = 0.24 (−0.006, 0.46) | ||||||
| Nemet et al. [30] 1986, Hungary | Cross-sectional | Sample size: 156 Maternal age: Fer <10 µg/l: 26.1 ± 5.0, Fer >20 µg/l: 27.2 ± 4.6 Malaria setting: No Iron supplementation: NR |
Maternal venous blood during labour Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Ferrozine colour agent for serum iron and TIBC. Radioimmunoassay for ferritin | Maternal: Ferritin Newborn: Ferritin, Serum iron, Tf Sat, TIBC |
r = 0.15 (−0.007, 0.30), 0.09 (−0.07, 0.24), −0.10 (−0.22, −0.02), −0.17 (−0.32, −0.01), | 3 |
| Maternal: Tf Sat Newborn: Ferritin, serum iron, Tf Sat, TIBC |
r = −0.12 (−0.27, 0.04), 0.04 (−0.12, 0.20), 0.04 (−0.12, 0.20), 0.04 (−0.12, 0.20) | ||||||
| Maternal: TIBC Newborn: Ferritin, serum iron, Tf Sat, TIBC |
r = 0.07 (−0.09, 0.22), 0.07 (−0.09, 0.22), 0.05 (−0.11, 0.21), −0.02 (−0.18, 0.14), | ||||||
| Nhonoli et al. [31] 1975, Tanzania | Cross-sectional | Sample size: 580 Maternal age (a): NR Malaria setting: Yes Iron supplementation: NR |
Maternal venous blood at delivery Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Chromogen for serum iron | Maternal: Serum iron Newborn: Serum iron |
r = 0.59 (0.53, 0.64) | 4 |
| Norimah et al. [32] 2010, Malaysia | Cross-sectional | Sample size: 70 Maternal age (a): 25.6 ± 4.9/ 17–40 Malaria setting: Yes Iron supplementation: NR |
Maternal venous blood at delivery Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Cyanmethaemoglobin for Hb. Radioimmunoassay for ferritin | Maternal: Ferritin Newborn: Ferritin, Hb |
r = 0.01 (−0.22, 0.25), 0.06 (−0.18, 0.29) | 5 |
| Maternal: Hb Newborn: Ferritin, Hb |
r = 0.06 (−0.18, 0.29), 0.42 (0.21, 0.60) | ||||||
| Maternal: Ht Newborn: Ferritin, Hb |
r = 0.008 (−0.23, 0.24), 0.23 (−0.007, 0.44) | ||||||
| Paiva Ade et al. [64] 2007, Brazil | Cross-sectional | Sample size: 95 Maternal age (a): anaemic: 22.9; iron deficient: 23.1; control: non-iron deficient: 24.8 Malaria setting: Yes Iron supplementation: NR |
Maternal venous blood at delivery Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Colorimetric method for serum iron. Turbidimetric method for TIBC. Chemiluminescence for ferritin. Haematofluorometry for ZPP. Method for haematologic indices NR |
Maternal: Ferritin Newborn: Ferritin, Tf Sat, TIBC, ZPP, Hb, MCV |
r = 0.07 (−0.13, 0.27), −0.02 (−0.22, 0.18), −0.02 (−0.22, 0.18), 0.10 (−0.10, 0.30) 0.05 (−0.15, 0.25), 0.12 (−0.08, 0.31) | 7 |
| Maternal: Serum iron Newborn: Ferritin, Serum iron, Tf Sat, TIBC, ZPP, Hb, MCV |
r = 0.04 (0.03, 0.44), 0.26 (0.06, 0.44), 0.20 (−0.001, 0.39), −0.08 (−0.39, 0.09), 0.10 (−0.10, 0.30), 0.00 (−0.20, 0.20), −0.11 (−0.30, 0.09) | ||||||
| Maternal: Tf Sat Newborn: Ferritin, Serum iron, Tf Sat, TIBC, ZPP, Hb, MCV |
r = −0.07 (−0.27, 0.13), 0.22 (0.02, 0.40), 0.23 (0.03, 0.41), −0.23 (−0.41, −0.03), −0.03 (−0.17, 0.23), 0.06 (−0.14, 0.26), −0.04 (−0.24, 0.16) | ||||||
| Maternal: TIBC Newborn: Ferritin, serum iron, Tf Sat, TIBC |
r = 0.20 (−0.0001, 0.39), 0.05 (−0.15, 0.25), −0.12 (0.31, 0.08), 0.42 (0.24, 0.57) | ||||||
| Maternal: ZPP Newborn: Ferritin, serum iron, Tf Sat, TIBC, ZPP, Hb, MCV |
r = −0.23 (−0.41, −0.03), −0.13 (−0.32, 0.07), 0.15 (−0.34, 0.05), 0.17 (−0.03, 0.36), −0.04 (−0.16, 0.24), 0.08 (−0.12, 0.28), 0.08 (−0.12, 0.28) | ||||||
| Maternal: Hb Newborn: Serum iron, Tf Sat, TIBC, ZPP, Hb, MCV |
r = 0.02 (−0.18, 0.22), −0.03 (−0.23, 0.17), 0.01 (−0.19, 0.21), 0.08 (−0.12, 0.28), 0.08 (−0.12, 0.28), 0.03 (−0.17, 0.23) | ||||||
| Pope et al. [33] 2014, Australia | Cross-sectional | Sample size: 91 Maternal age (a): 33.7 ± 4.9 Malaria setting: No Iron supplementation: NR |
Maternal blood at delivery Umbilical cord blood at delivery Inflammation biomarkers: CRP Factors adjusted: NR |
Biochemistry analyser for serum iron, TIBC; automated haematology analyser for haematologic indices | Maternal: Ferritin Newborn: Ferritin |
r = −0.05 (−0.25, 0.16) | 4 |
| Maternal: Serum iron Newborn: Serum iron |
r = 0.15 (−0.06, 0.34) | ||||||
| Maternal: Tf Sat Newborn: Tf Sat |
r = 0.12 (−0.09, 0.32) | ||||||
| Maternal: TIBC Newborn: TIBC |
r = −0.18 (−0.37, 0.03) | ||||||
| Maternal: Hb Newborn: Hb |
r = 0.02 (−0.19, 0.22) | ||||||
| Maternal: MCHb Newborn: MCHb |
r = 0.07 (−0.14, 0.27) | ||||||
| Maternal: MCV Newborn: MCV |
r = −0.09 (−0.29, 0.12) | ||||||
| Qaiser et al. [65] 2013, Pakistan | Cross-sectional | Sample size: 404 Maternal age (a): 15–45 Malaria setting: Yes Iron supplementation: NR |
Maternal venous blood during labour Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Standard coultergram using Beckman Coulter Max M | Maternal: Hb Newborn: Hb |
r = 0.12 (0.02, 0.22) | 6 |
| Maternal: Ht Newborn: Ht |
r = 0.23 (0.14, 0.32) | ||||||
| Maternal: MCHb Newborn: MCHb |
r = 0.17 (0.07, 0.26) | ||||||
| Maternal: MCV Newborn: MCV |
r = 0.30 (0.21, 0.39) | ||||||
| Ramirez-Cardich et al. [34] 2004, Peru | Cross-sectional | Sample size: 36 Maternal age (a): 28.1 ± 1.1 Malaria setting: Yes Iron supplementation: NR |
Maternal blood <12 h prior to delivery Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Microcapillary method | Maternal: Ht Newborn: Ht |
r = −0.57 (−0.76, −0.30) | 5 |
| Rioux et al. [85] 2001, Canada | Retrospective cohort | Sample size: 952 Maternal age (a): NR Malaria setting: No Iron supplementation: NR |
Maternal blood collected at 1st, 2nd and 3rd trimester and 12 hrs postpartum Neonatal blood <48 hrs after delivery Inflammation biomarkers: NR Factors adjusted: NR |
NR | Maternal: Hb Newborn: Hb, Ht |
r = 0.13 (0.07, 0.19), 0.08 (0.02, 0.14) | 5 |
| Maternal: Ht Newborn: Hb, Ht |
r = 0.10 (0.04, 0.16), 0.08 (0.02, 0.14) | ||||||
| Rusia et al. [35] 1996, India | Cross-sectional | Sample size: 100 Maternal age (a): 17–39 Malaria setting: Yes Iron supplementation: NR |
Maternal venous blood during labour Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Automated particle counter for haematologic indices. ELISA for ferritin Method for serum iron NR |
Maternal: Ferritin Newborn: Ferritin |
r = 0.14 (−0.06, 0.32) | 4 |
| Maternal: Serum iron Newborn: Serum iron |
r = 0.44 (0.27, 0.58) | ||||||
| Maternal: Tf Sat Newborn: Tf Sat |
r = 0.30 (0.11, 0.47) | ||||||
| Maternal: Hb Newborn: Hb |
r = 0.41 (0.23, 0.56) | ||||||
| Shao et al. [66] 2012, China | Cross-sectional | Sample size: 3891 Maternal age (a): 26.4 ± 3.6/ 20–35 Malaria setting: Yes Iron supplementation: NR |
Timing of maternal blood collection NR Umbilical cord blood at delivery Inflammation biomarkers: CRP Factors adjusted: NR |
Auto analyser for haematologic indices. Chemiluscent assay for ferritin. | Maternal: Ferritin Newborn: Ferritin, Hb |
r = 0.07 (0.04, 0.10), 0.01 (−0.02, 0.04) | 6 |
| Maternal: Hb Newborn: Hb |
r = 0.10 (0.07, 0.13) | ||||||
| Shukla et al. [83] 2019, India | Prospective cohort | Sample size: 163 Maternal age (a): NR Malaria setting: Yes Fe supplementation: NR |
Timing of maternal blood collection NR Venous blood at 14 weeks Inflammation biomarkers: NR Factors adjusted: NR |
NR | Maternal: Ferritin Newborn: Ferritin |
r = 0.23 (0.08, 0.37) | 7 |
| Maternal: Hb Newborn: Hb |
r = 0.23 (0.08, 0.37) | ||||||
| Sichieri et al. [67] 2006, Brazil | Cross-sectional | Sample size: 82 Maternal age (a): NR Malaria setting: Yes Iron supplementation: NR |
Maternal venous blood; timing NR Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Plasma-atomic emission spectroscopy for serum iron; Automated analyser for Hb and Ht | Maternal: Serum iron Newborn: Serum iron |
r = 0.21 (−0.007, 0.41) | 4 |
| Maternal: Hb Newborn: Hb |
r = 0.04 (−0.18, 0.25) | ||||||
| Maternal: Ht Newborn: Ht |
r = 0.15 (−0.07, 0.36) | ||||||
| Sikorsi et al. [68] 1998, Poland | Cross-sectional | Sample size: 100 Maternal age (a): 15–42 Malaria setting: No Iron supplementation: NR |
Maternal venous blood during labour Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Atomic absorption spectroscopy | Maternal: Serum iron Newborn: Serum iron |
r = 0.08 (−0.12, 0.27) | 3 |
| Singla et al. [36] 1978, India | Cross-sectional | Sample size: 85 Maternal age (a): NR Malaria setting: Yes Iron supplementation: NR |
Maternal venous blood during labour Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
NR | Maternal: Serum iron Newborn: Serum iron |
r = 0.41 (0.22, 0.58) | 5 |
| Maternal: Tf Sat Newborn: Tf Sat |
r = 0.33 (0.12, 0.50) | ||||||
| Maternal: Hb Newborn: Hb |
r = 0.73 (0.61, 0.82) | ||||||
| Srivastava et al. [37] 2002, India | Cross-sectional | Sample size: 54 Maternal age (a) NR Malaria setting: Yes Iron supplementation: NR |
Maternal blood at delivery Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Flame atomic absorption spectroscopy | Maternal: Serum iron Newborn: Serum iron |
r = −0.02 (−0.29, 0.25) | 5 |
| Tamura et al. [82] 1999, USA | Prospective cohort | Sample size: 255 Maternal age (a): Mothers of female neonates: 24.6 ± 4.3; mothers of male neonates: 24.1 ± 4.3 Malaria setting: No Iron supplementation: All women |
Maternal blood at 10–36 weeks Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: Maternal race, age, height, prepreg weight and BMI, smoking, alcohol |
Radio-immunoassay | Maternal: Ferritin Newborn: Ferritin |
r = 0.32 (0.21, 0.43) (male babies), r = 0.09 (−0.03, 0.21) (female babies) | 4 |
| Tekinalp et al. [69] 1996, Turkey | Cross-sectional | Sample size: 76 Maternal age (a): NR Malaria setting: Yes Iron supplementation: NR |
Maternal venous blood postpartum Peripheral vein at delivery Inflammation biomarkers: NR Factors adjusted: NR |
ELISA | Maternal: Ferritin Newborn: Ferritin |
r = 0.16 (−0.06, 0.38) (anaemic mothers), r = 0.33 (0.12, 0.52) (non-anaemic mothers) | 3 |
| Terefe et al. [38] 2015, Ethiopia | Cross-sectional | Sample size: 89 Maternal age (a): Median age 23; IQR 21–27 Malaria setting: Yes Iron supplementation: Some women |
Maternal venous blood during labour Umbilical cord blood at delivery Inflammation biomarkers: CRP Factors adjusted: NR |
Automated Cobas for ferritin, Automated analyser for haematologic indices | Maternal: Ferritin Newborn: Ferritin, Hb, MCHb, MCV |
r = 0.38 (0.19, 0.55), 0.28 (0.08, 0.46), 0.10 (−0.11, 0.30), −0.05 (−0.26, 0.16) | 6 |
| Maternal: Hb Newborn: Ferritin, Hb, MCHb, MCV |
r = 0.25 (0.04, 0.44), 0.22 (0.01, 0.41), 0.15 (−0.06, 0.35), 0.06 (−0.15, 0.26) | ||||||
| Timilsina et al. [70] 2018, Nepal | Cross-sectional | Sample size: 114 Maternal age (a): 26.0 ± 3.5 Malaria setting: Yes Iron supplementation: All women |
Maternal venous blood when presenting for delivery Umbilical cord 2 min after delivery Inflammation biomarkers: NR Factors adjusted: NR |
Haematology analyser | Maternal: Hb Newborn: Hb |
r = 0.50 (0.34, 0.62) | 6 |
| Maternal: Ht Newborn: Ht |
r = 0.11 (−0.08, 0.29) | ||||||
| Maternal: MCHb Newborn: MCHb |
r = 0.48 (0.32, 0.61) | ||||||
| Maternal: MCV Newborn: MCV |
r = 0.06 (−0.13, 0.24) | ||||||
| Vahlquist et al. [71] 1975, Sweden | Cross-sectional | Sample size: 49 (1 pair of twins included) Maternal age (a): NR Malaria setting: No Iron supplementation: NR |
Timing of maternal blood collection NR Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Radioimmunodiffusion | Maternal: Tf Sat Newborn: Tf Sat |
r = 0.21 (−0.08, 0.46) | 2 |
| Vasquez-Molina et al. [72] 1982, Mexico | Cross-sectional | Sample size: 163 Maternal age (a): NR Malaria setting: Yes Iron supplementation: All women |
Maternal venous blood during labour Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Cyanmethaemoglobin for Hb. Microcapillary for Ht. Chemiluminometric assay for ferritin | Maternal: Ferritin Newborn: Ferritin |
r = 0.14 (−0.01, 0.29) | 5 |
| Maternal: Hb Newborn: Hb |
r = 0.11 (−0.04, 0.26) | ||||||
| Maternal: Ht Newborn: Ht |
r = 0.09 (−0.06, 0.24) | ||||||
| Vobecky et al. [73] 1982, Canada | Cross-sectional | Sample size: 556 Maternal age (a): 26.3 ± 4.2/ 15–43 Malaria setting: No Iron supplementation: NR |
Maternal venous blood during labour Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Cyanmethaemoglobin for Hb. Photometric determination for serum iron; method for Ht NR | Maternal: Serum iron Newborn: Serum iron |
r = −0.03 (95%CI −0.11, 0.05) | 5 |
| Maternal: Hb Newborn: Hb |
r = 0.08 (−0.003, 0.16) | ||||||
| Maternal: Ht Newborn: Ht |
r = 0.14 (0.06, 0.22) | ||||||
| Wong et al. [39] 1990, Singapore | Cross-sectional | Sample size: 72 Maternal age (a): 28.1 ± 4.9/ 16–41 Malaria setting: No Iron supplementation: All women |
Maternal blood at delivery Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
ELISA | Maternal: Ferritin Newborn: Ferritin |
Maternal 17.4 ± 12.5 µg/L; Newborn 142±68.6 µg/L | 4 |
| Wong et al. [40] 1991, Singapore | Cross-sectional | Sample size: 352 Maternal age (a): NR Malaria setting: No Iron supplementation: NR |
Maternal venous blood at delivery Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Rocket immunoelectrophoresis | Maternal: TF Newborn: TF |
r = 0.0064 (−0.10, 0.11) | 2 |
| Yepez et al. [74] 1987, Ecuador | Cross-sectional | Sample size: 84 Maternal age (a): 20.2 ± 3.3 Malaria setting: Yes Iron supplementation: None |
Maternal venous blood during labour Umbilical cord blood at delivery Inflammation biomarkers: NR Factors adjusted: NR |
Cyanmethaemoglobin for Hb. Microcentrifugation for Ht. Colorimetric technique for serum iron. ELISA for ferritin | Maternal: Ferritin Newborn: Hb |
r = 0.25 (0.04, 0.44) | 5 |
| Maternal: Serum iron Newborn: Serum iron |
r = 0.26 (0.05, 0.45) | ||||||
| Maternal: Hb Newborn: Hb |
r = 0.28 (0.07, 0.47) |
a, years; BMI, body mass index; CRP, C-reactive protein; ELISA, enzyme-linked immunoassay; Hb, haemoglobin; Ht, haematocrit; MCHb- mean corpuscular haemoglobin; MCV, mean corpuscular/cell volume; NR, not reported; sTfR, serum/soluble transferrin receptor; Tf, transferrin; Tf Sat, transferrin saturation; TIBC, total iron binding capacity; ZPP, zinc protoporphyrin.