The amount of additional iron needed for RBCs expansion depends on the numbers of fetuses. WHO recommends iron supplements 30–60 mg/day if the woman has iron stores; if not 120–240 mg/day advocated Current target Hb concentrations in each trimester are based on supplementation trials, which suggest that Hb > 11g in first and third trimesters and 10.5 g in the second trimester represent reasonable clinical expectations of lower normal levels ( U shape)

Iron Absorption The capacity to increase the efficiency of iron absorption appears to maximize at around 40–60% in the second trimester The efficiency of iron absorption is strongly associated with the iron status of the woman; more ferritin are much less efficient than women with a low ferritin level When there is insufficient dietary and reserve iron to meet the demands, essential body iron from maternal pools are sacrificed with a resulting maternal iron deficiency. The placental transfer of iron with severe iron deficiency associated with upregulation of placental ferritin receptors and presumably an increase in placental-fetal transfer of iron

Assessment Of Iron Status Assessing iron status cannot rely solely on Hb, hematocrit (Hct) value. The various categories of iron status, adequate, low or depleted iron stores, iron deficient erythropoiesis, and iron deficiency anemia, are all characterized by a range of values of a number of biomarkers that are sensitive to iron storage, iron transport, or tissue iron deficiency

Consequences Of This Negative Iron Balance The effect of depletion of the essential body pools of iron include anemia, altered hormone metabolism, altered energy metabolism, depressed immune functioning, and changes in behavior and cognition. The possible causal routes include direct and indirect effects of anemic hypoxia, placental delivery of iron, and alterations in hormonal control of pregnancy due to alterations in the stress: hypothalamic–pituitary–adrenal axis system. Maternal anemia has been related to maternal mortality, fetal mortality, fetal growth retardation, pregnancy complications, and a small amount on infant growth

Anemia And Birth Weight, Gestational Age, And Infant Mortality There is a U-shaped curve relationship between the maternal hemoglobin concentration and the proportion of LBW infants. The cause of the elevation in prevalence of LBW infants with high Hgb is improper expansion of the maternal plasma volume, while insufficient erythropoiesis and poor volume expansion in low Hgb. The optimal maternal Hb for minimal incidence of LBW in the published literature varies.

The hemoglobin concentration and the definition of anemia are trimester dependent, with a clear nadir of concentration in mid-gestation. Severity of anemia is an additional factor associated with an increased risk of LBW and prematurity with severe anemia (Hb < 8g)

Maternal Anemia And Mortality Maternal mortality is correlated with the severity of anemia in pregnancy. Severe anemia (Hb < 6–7 g/l or Hct < 0.14) is associated with an increased rate of maternal death. In very severe anemia, the death rate may be as high as 20%, greater than the comparison group of minimum mortality. Transfusion is needed. When the Hb is this low, compensatory mechanisms begin to fail, lactic acid levels rise, and cardiac failure may occur.

Iron Deficiency Anemia And Pregnancy Outcomes Iron deficiency anemia has an impact on fetal G&D similar to anemia in general. Particularly in the first trimester, it is more strongly related to prematurity and LBW than anemia of any cause later in pregnancy; anemia at other times had little effect. Lower maternal iron status is associated with lower cord blood iron, prematurity, and lower Apgar scores

Based on several studies, there is a relationship of elevated ferritin with preterm birth, LBW, and preeclampsia. Higher ferritin concentrations may be more an indication of upper genital tract infection and a subsequent development of spontaneous preterm delivery than an indication that higher iron status is bad for fetal G&D. Elevations of ferritin in mid-gestation increase the risk for pregnancy complications

Prophylactic iron supplementation during the first trimester of pregnancy in poor women improves birth weight, lower the incidence of prematurity, but did not alter the incidence of SGA deliveries Timing and dose of supplementation, as well as the frequency of supplementation, are important considerations in interventions during pregnancy. The most common side effects of iron include black stools, constipation, GI upset, and vomiting.

Alternative strategies to minimize the need for oral iron supplements include a diet that is high in iron- containing foods; most notably this is red meat. Fish, lamb, and other meats also contain significant amounts of iron. A reduction in inhibitors of iron absorption (tea, coffee, high-phytate-containing grains and breads) may provide some addition benefit in terms of bioavailable iron.

Maternal Iron Status And Other Fetal Outcomes Infant Development There is a relationship between newborn cord ferritin levels and cognition and behavior at 5 years of age. Infants of iron-deficient anemic mothers had lower developmental scores than had infants of mothers who were not anemic. Maternal postpartum depression related to Hb concentration in the months after delivery of the infant may contribute to changes in infant development

Infant Iron Status There is a general correlation between maternal Hb in the third trimester with the infant Hb at 9 months of age. M anemia may be related to infant anemia in early life on some occasions, but commonly the relationship is more strongly expressed at 9–12 months of age when infant iron stores have been exhausted.

Conclusion Iron deficiency and anemia during pregnancy have functional outcomes for both the mother and the developing infant. The strong epidemiological data show a strong impact of anemia during the first trimester on the short-term outcomes of pregnancy such as gestational age and birth weight.

The severity of iron deficiency and anemia over the course of pregnancy appears to be a determinant of postnatal development of infants and their neurodevelopment in the first and second years of life. As it is very difficult to begin oral iron treatment before the 8–10th week of pregnancy, it might be prudent to adopt the approach of the folic acid supplementation recommendations and suggest that women who plan to become pregnant be certain their iron status is good. This means the serum ferritin should be higher than 40–50 mcg/l prior to pregnancy and the woman should be quite faithful in her consumption of modest doses of iron supplements.