Effect of Maternal Iron Deficiency Anemia on Fetal Hemodynamics and Neonatal Outcome

Hemoglobin concentration is used to determine the diagnosis and severity of anemia in low resource settings, an indicator that is routinely screened using WHO-defined hemoglobin cutoffs. These thresholds are lower for pregnant women (females ≥ 15 years of age) than non-pregnant women (11.0 g/dl versus 12.0 g/dl). Severity of anemia is determined using additional cutoffs, with severe anemia defined as a hemoglobin level of less than 7.0 g/dl.

Iron deficiency is defined as a condition in which there are no mobilizable iron stores, resulting from a long-term negative iron balance and leading to a compromised supply of iron to the tissues. Finally, the most significant negative consequence of ID is anemia, usually microcytic hypochromic in nature.

IDA has been linked to unfavorable outcomes of pregnancy. It is the most common nutritional disorder in the world affecting two billion people worldwide with pregnant women particularly at risk. According to WHO report, 2001 indicates that IDA is a significant problem throughout the world ranging from 35-75% in developing countries (average 56%) whereas in industrialized countries the average prevalence is 14%.

Distribution of blood flow (between the placental and cerebral regions) is determined with Middle cerebral artery PI/Umbilical artery PI (C/U ratio); this parameter is always > 1.1 during normal pregnancy, but decreases in the case of hypoxia because of umbilical artery resistance index increase (increase in placental resistance) and cerebral resistance index decrease (cerebral vasodilation).

Perinatal morbidity & mortality of IUGR infants is 3-20 times greater than normal infants. These cases may be followed with outpatient monitoring and they often deliver at term. However process is not severe enough to stop fetal growth completely or to deteriorate. The umbilical artery and the middle cerebral artery waveforms may be abnormal, without effect is seen on Doppler and growth until 26-32 weeks gestation; Mild utero-placental insufficiency.