Table 1.
Study characteristics and risk of bias assessment
| Author (year), country | Objective studied | Mean Age | Mean Gestational age | Study design | Recent Transfusion (< 6 months) | Hemoglobin genotype (number of participants) | Sample size | Diagnostic method | Diagnostic criteria | Participants with IDA | Prevalence | Bias |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Akinyanju et al. (1987), Nigeria [13] | 1,3 | 22.8 | NA | Randomized control trial | None |
SS (11) SC (3) |
14 | Bone marrow iron stain |
Grade 0–1/5 |
3 | 21.43 ± 4.49 |
Selection bias: unclear Reporting bias: unclear Performance bias: unclear Detection bias: unclear Attrition bias: Low |
| Anderson et al. (1972), Jamaica [22] | 1 | 25.27 | 16.93 | Cross sectional study | Nonea |
SS (7) SC (6) S-thalassemia (2) |
15 |
Bone marrow iron stain Serum iron TIBCb |
Grade 0–1/3 < 50 ng/dl < 240 μg/dl |
10 1 1 |
66.67 ± 15.94 6.67 ± 0.87 6.67 ± 0.87 |
Fair |
| Oluboyede et al. (1980), Nigeria [14] | 1 | NA | 23.3 | Case control study | None |
SS (10) SC (12) |
22 | Bone marrow iron stain |
Grade 0–1/3 |
14 | 63.34 ± 12.78 | Fair |
| Roopnarinegnh (1976), Spain [23] | 1 | NA | 28.67 | Cross sectional study | None |
SS (5) SF (1) |
6 | Bone marrow iron stain |
Negative & weakly positive |
5 | 83.33 ± 25.04 | Fair |
| Aken’ova et al. (1977), Nigeria [24] | 1 | NA | NA | Cross sectional study | NA | SS | 10 |
Serum ferritin Serum iron |
< 150 ng/dl < 50 ng/dl |
3 3 |
30 ± 8.52 30 ± 8.52 |
Fair |
aThree patients had been transfused at least once; 5 years, 3 years and 6 months prior to the pregnancy, bTotal iron binding capacity, NA: not provided in study, IDA; iron deficiency anaemia, SS; Haemoglobin SS, SC; Haemoglobin SC, SF; Haemoglobin SF, Prevalence is reported with ± confidence intervals