As many as three of 10 women have postpartum hemoglobin (Hb) levels less than 10 g/dL and 10% reportedly have levels less than 8 g/dL—principally because of iron deficiency. Both an increased need for iron by the fetoplacental unit and an increased maternal red cell mass contribute to the deficit. Oral iron supplementation is the preferred approach in most centers in the UK; only women who are more severely affected or symptomatic receive transfusions. Oral supplementation is not a reliable treatment for severe anemia, however, because of its limited absorption and adverse gastrointestinal effects that may lessen compliance. An alternative is to administer iron intravenously in the form of ferrous sucrose. These 2 modes of iron therapy were compared in a prospective randomized trial enrolling 44 women at a single center with iron deficiency anemia (IDA), defined as a Hb level below 9 g/dL and a ferritin level less than 15 μg/L when measured 24 to 48 hours after delivery. Participants received either 200 mg of oral ferrous sulfate twice a day for 6 weeks, or 200 mg intravenously on days 2 and 4 following recruitment.
Among the 43 women for whom data were available, the two treatment groups had similar clinical and biochemical features at baseline. All women but one delivered by elective cesarean. Levels of Hb increased in both treatment groups on days 5, 14, and 40, but were higher in the IV group at days 5 and 14. On day 5, the average Hb increase was 2.5 g/dL in the IV group and 0.7 g/dL in the oral group; no significant difference was recorded at day 40. Ferritin levels increased only in the IV group, from 13.0 μg/L at baseline to 42.2 μg/L on day 40; the level on day 40 in the oral group was 15.0 μg/L. Serum iron levels increased in both groups but were significantly higher in the IV group on days 14 and 40. There were no serious adverse effects. A few women in the IV group reported facial flushing or a transient metallic taste during iron infusion. One-third of women in the oral group had gastrointestinal side effects which, however, did not compromise compliance with iron supplementation.
In women with postpartum IDA, intravenous ferrous sucrose produces higher blood hemoglobin levels than oral iron supplementation and also appears to replenish iron stores more rapidly.