Table 4.

The characteristics of the participants of the randomized controlled trials included in the systematic review [22,23,24,25,26,27,28].

Ref.	Number of Participants	Age (Mean/Median/Range)	Inclusion Criteria	Exclusion Criteria
[24]	259	25.4 years	Pregnancy; 12–34 week of gestation; attending prenatal clinics in the hospitals and surrounding health centers of Mpwapwa and Kongwa districts	Hemoglobin concentration of <80 g/L; serious medical condition; complication of pregnancy such as cardiac disease, pneumonia, and threatened abortion
[25]	168	25.0–25.8 years, depending on group	Pregnancy; age of 20–32 years; no more than two prior pregnancies; hemoglobin > 70 g/L	Stillbirths, premature births, or hemorrhage in previous pregnancies; manifestations of chronic or infectious diseases, including hookworm infection; planned travel or plans to move out of the area during the study period
[22]	205	Not specified	Pregnancy; anemia (hemoglobin 50–90 g/L); urinary fluoride > 1.0 mg/L	Gestation > 20 weeks; diabetes; tuberculosis; bleeding during pregnancy; high blood pressure; HIV/AIDS; malaria; other medical problems
[26]	227	15–49 years	Pregnancy; age of 15–49 years; 12–20 weeks of gestation; predicted singleton neonates	Severe maternal illness
[27]	86	22.9–23.2 years, depending on group	Pregnancy; age of 15–45 years; a history of amenorrhea; 13–28 week of gestation	Acute illness; severe medical or obstetrical complications; multiple pregnancy; gestational diabetes; not staying for a minimum period of 12 weeks in the study area
[28]	495	26.2–26.9 years, depending on group	Pregnancy; age of ≥18 years; being in the first trimester of pregnancy; planning to stay in the home village for the duration of the pregnancy	Fetal loss; migration
[23]	93	27.3–29.5 years, depending on group	Pregnancy; age of ≥18 years; 14–28 weeks of gestation; iron-deficiency anemia (hemoglobin level of 70–100 g/L)	Anemia predominantly caused by factors other than iron-deficiency (e.g., anemia with untreated B12 or folate deficiency, hemolytic anemia); iron overload or disturbances in utilization of iron (e.g., hemochromatosis and hemosiderosis); decompensated liver cirrhosis and active hepatitis; active acute or chronic infections; rheumatoid arthritis with symptoms or signs of active inflammation; history of multiple allergies; gastrointestinal tract diseases; known hypersensitivity to parenteral iron or any recipients in the investigational drug products; receiving erythropoietin treatment within 8 weeks prior to the screening visit or other iron treatment or blood transfusion within 4 weeks prior to the screening visit