Maternal iron status and intrauterine growth retardation

Abstract

The objective of this study was to compare the iron status of 356 mother-baby pairs who had intrauterine growth retardation (IUGR) with 356 mother-baby pairs who had appropriate weight for gestational age (AGA). Mothers were selected in 1991/92 from 4 hospitals in Campinas city, Brazil, where 95% of deliveries take place. Gestational age of the newborns was determined by the Capurro method. Newborns were classified as having IUGR according to the Lubchenco birthweight for gestational age standard. Haemoglobin (Hb), haematocrit (Ht) and ferritin were determined, respectively, by the cyanmethaemoglobin method, an haematocrit centrifuge, and an immunoenzymetric assay. Mean levels of Hb and Ht were higher in IUGR (16.4 g/dL; 51.7%) than in AGA babies (15.7 g/dL; 49.7%) (P < 0.001), as a consequence of intrauterine hypoxia. Higher maternal levels of ferritin (> 50 micrograms/L) were more common in IUGR than in AGA mothers (P < 0.001). Forty-seven percent (335/712) of the IUGR and AGA mothers were anaemic (Hb < or = 11.0 g/dL), but only 4.4% (31/356) of them had low levels of ferritin (< or = 10 micrograms/L). We advise further large epidemiological studies involving IUGR and AGA mother-baby pairs, elucidating the mechanisms underlying the plasma-volume changes in pregnancy, and the prevalence of iron-deficiency anaemia assessed by different indicators, in view of the fact that ferritin can be affected by inflammation and infection, important risk factors for IUGR in developing countries.

Erythrocyte indices and serum ferritin in newborns

“…Higher mean values for Hb, RBC and Hct, in term SGA newborns compared to other newborns, have previously been reported in other studies. (3)(4)(5) It is known that chronic fetal hypoxia, due to poor placental function in The interviewee had to answer the question, "What is your color or race?" and was asked to choose one of the above mentioned options.…”

“…(24) Despite the fact that, infants with intrauterine growth restriction (IUGR) are at risk of iron deficiency, (25) term SGA newborns in this study presented the highest mean values for serum ferritin, different to the results of a previous study. 4 Low serum ferritin values are good indicators of iron deficiency; high values in contrast, are usually associated with inflammation/infection and frequently associated with IUGR. (24,26) In fact, serum ferritin may not be the appropriate indicator of iron deposit in SGA newborns; however there is no standard test for the diagnosis of iron status at birth (27) and, in this case, a combination of different tests would be appropriate.…”

“…Some investigators have reported term, small-for-gestationalage (SGA) newborns as having higher levels of hemoglobin (Hb), red blood cells (RBC) and hematocrit (HCT), compared to appropriate-for-gestational-age (AGA) newborns. (2)(3)(4)(5) Furthermore, studies have reported lower values for preterm AGA newborns. (3,6) Reference hematological values for cord blood have not been standardized, and routinely out of date values proposed in the literature are used.…”

“…(7) In published studies, information on hematological values in cord blood is limited and inconsistent. The studies that we found (3)(4)(5)(6)(8)(9)(10) evaluated different subgroups of neonates and different hematological parameters. In particular, little data regarding hematological parameters of SGA newborns was found.…”

“…In particular, little data regarding hematological parameters of SGA newborns was found. (3)(4)(5)9) However, the impaired fetal growth and/or the condition of SGA are associated with increased infant mortality and various morbidities, including hematological changes.…”