Iron Stores in Early Pregnancy and Risk of Lower Birthweight
Iron Stores in Early Pregnancy and Risk of Lower Birthweight
BACKGROUND Gestational iron-deficiency anaemia has adverse pregnancy outcomes. Antenatal iron supplementation can be beneficial in anaemic women, but the effects in non-anaemic women are controversial. This observational study assessed the relationship of maternal iron stores (depleted or non-depleted) at gestational Weeks 8–12 with birthweight, in non-anaemic pregnant women following the guidelines of the Ministry of Health of Spain.
METHODS Healthy, non-anaemic pregnant women (n = 205) were studied. At the first antenatal visit, a general clinical assessment was conducted, and basal blood taken. Women were classified as having non-depleted or depleted iron stores [serum ferritin (SF) < 12 µg/l)]. Daily antenatal iron supplements (48 mg on average) were started at 17 (range: 16–18) weeks. Blood haemoglobin, SF and transferrin saturation (TS) were measured in each trimester.
RESULTS Of the study sample, 20, 54 and 66% had SF < 12 µg/l in the first, second and third trimesters, respectively. The prevalence of iron-depletion (SF < 12 µg/l) and iron-deficiency (SF < 12 µg/l and TS < 16%) was greater during the entire pregnancy in women with initial iron depletion versus no depletion (81.6 and 73.7% versus 61.7 and 55.4%, respectively, in the third trimester, P < 0.05). Women with initial iron-depletion delivered babies weighing on average 192 g less than that with initial iron stores, after adjusting for confounding variables (P = 0.028).
CONCLUSIONS Beginning pregnancy with non-depleted iron stores is beneficial for the maternal iron status during pregnancy and infant birthweight. These findings reaffirm the importance of health promotion to ensure that women have adequate iron stores prior to, or early in, pregnancy when supplemented with moderate daily iron doses.
Many women of child-bearing age have depleted iron stores. Throughout Europe and other industrialized countries between 11 and 45% of women of fertile age have been reported to have serum ferritin (SF) concentrations ranging between 10 and 17 µg/l (Hallberg, 1995), indicating minimal or absent iron stores.
Iron requirements are higher during the second and third trimesters of pregnancy owing to growth of the foeto-placental unit and to expansion of the maternal erythrocyte mass. This implies a higher risk of iron deficiency in this group (Bothwell, 2000).
Iron-deficiency anaemia during pregnancy is linked to important adverse health effects for the mother and fetus, such as increased rates of premature birth, low infant birthweight (IBW; Rasmussen, 2001; Ronnenberg et al. 2004; Scholl, 2005) and delayed maturation and cognitive and motor capacity of the child (Hercberg et al., 2000; Hernández-Martínez et al., 2011).
Iron requirements during pregnancy are high and are difficult to achieve by diet alone (Bothwell, 2000). The situation is further complicated when the woman starts pregnancy with insufficient iron stores (World Health Organization, 2001). The World Health Organization (WHO) highlights the importance of starting iron supplementation early in pregnancy in order to prevent iron deficiency in mothers, and adverse effects on mother and child (World Health Organization, 2001, 2007). Starting pregnancy with good iron status can pre-empt these adverse effects.
The relationships between anaemia at the start of pregnancy and adverse effects on mother and child have received considerable attention (Scanlon et al., 2000; Ronnenberg et al., 2004). Anaemia with iron depletion early in pregnancy compared with anaemia by other causes has been associated with an increased risk of lower IBW (Scholl et al., 1992). Having identified anaemia with iron depletion as a risk factor for adverse outcomes, we wished to assess whether iron depletion in women without anaemia early in pregnancy also impairs IBW.
Hence, in the present study we investigated IBW in relation to maternal iron stores (depleted or non-depleted, based on SF levels) early in pregnancy in non-anaemic pregnant women receiving antenatal moderate iron supplementation.
Abstract and Introduction
Abstract
BACKGROUND Gestational iron-deficiency anaemia has adverse pregnancy outcomes. Antenatal iron supplementation can be beneficial in anaemic women, but the effects in non-anaemic women are controversial. This observational study assessed the relationship of maternal iron stores (depleted or non-depleted) at gestational Weeks 8–12 with birthweight, in non-anaemic pregnant women following the guidelines of the Ministry of Health of Spain.
METHODS Healthy, non-anaemic pregnant women (n = 205) were studied. At the first antenatal visit, a general clinical assessment was conducted, and basal blood taken. Women were classified as having non-depleted or depleted iron stores [serum ferritin (SF) < 12 µg/l)]. Daily antenatal iron supplements (48 mg on average) were started at 17 (range: 16–18) weeks. Blood haemoglobin, SF and transferrin saturation (TS) were measured in each trimester.
RESULTS Of the study sample, 20, 54 and 66% had SF < 12 µg/l in the first, second and third trimesters, respectively. The prevalence of iron-depletion (SF < 12 µg/l) and iron-deficiency (SF < 12 µg/l and TS < 16%) was greater during the entire pregnancy in women with initial iron depletion versus no depletion (81.6 and 73.7% versus 61.7 and 55.4%, respectively, in the third trimester, P < 0.05). Women with initial iron-depletion delivered babies weighing on average 192 g less than that with initial iron stores, after adjusting for confounding variables (P = 0.028).
CONCLUSIONS Beginning pregnancy with non-depleted iron stores is beneficial for the maternal iron status during pregnancy and infant birthweight. These findings reaffirm the importance of health promotion to ensure that women have adequate iron stores prior to, or early in, pregnancy when supplemented with moderate daily iron doses.
Introduction
Many women of child-bearing age have depleted iron stores. Throughout Europe and other industrialized countries between 11 and 45% of women of fertile age have been reported to have serum ferritin (SF) concentrations ranging between 10 and 17 µg/l (Hallberg, 1995), indicating minimal or absent iron stores.
Iron requirements are higher during the second and third trimesters of pregnancy owing to growth of the foeto-placental unit and to expansion of the maternal erythrocyte mass. This implies a higher risk of iron deficiency in this group (Bothwell, 2000).
Iron-deficiency anaemia during pregnancy is linked to important adverse health effects for the mother and fetus, such as increased rates of premature birth, low infant birthweight (IBW; Rasmussen, 2001; Ronnenberg et al. 2004; Scholl, 2005) and delayed maturation and cognitive and motor capacity of the child (Hercberg et al., 2000; Hernández-Martínez et al., 2011).
Iron requirements during pregnancy are high and are difficult to achieve by diet alone (Bothwell, 2000). The situation is further complicated when the woman starts pregnancy with insufficient iron stores (World Health Organization, 2001). The World Health Organization (WHO) highlights the importance of starting iron supplementation early in pregnancy in order to prevent iron deficiency in mothers, and adverse effects on mother and child (World Health Organization, 2001, 2007). Starting pregnancy with good iron status can pre-empt these adverse effects.
The relationships between anaemia at the start of pregnancy and adverse effects on mother and child have received considerable attention (Scanlon et al., 2000; Ronnenberg et al., 2004). Anaemia with iron depletion early in pregnancy compared with anaemia by other causes has been associated with an increased risk of lower IBW (Scholl et al., 1992). Having identified anaemia with iron depletion as a risk factor for adverse outcomes, we wished to assess whether iron depletion in women without anaemia early in pregnancy also impairs IBW.
Hence, in the present study we investigated IBW in relation to maternal iron stores (depleted or non-depleted, based on SF levels) early in pregnancy in non-anaemic pregnant women receiving antenatal moderate iron supplementation.
Source...