[Effect of maternal iron status on infant's iron level: a prospective study].

Objective: To investigate the effect of maternal iron levels in second trimester of pregnancy on the infants' early iron status, explore the relationship between maternal and infant's iron status, and analyze the main factor influencing anemia of the infants.

Methods: Totally 100 couples of mother-baby were followed up from the second trimester of the mothers' pregnancy till the babies were 3 - 5 months old in the Department of Primary Child Care from March 2006 to February 2007. The maternal venous blood samples were collected in the second and the third trimesters and were analyzed for Hb at the same time. The infants' venous blood samples were collected at the end of the follow-up visit and were analyzed for Hb. The values of sTfR of the infants were compared with the maternal iron status diagnostic criteria. The infant's weight was measured during the visits by two professional staff members. The physical growth was assessed with CDC2000 reference.

Results: (1) Among 100 couples of mother-baby, none of the Hb values was lower than 90 g/L during the whole period of survey. The prevalence of ID in the babies at the ages of 3-5 months was 39%. Among them 36 cases (36/39, 92.31%) were born to the mother with ID during pregnancy; 26 couples of mother-infant had normal iron status during the following study. (2) The ID' prevalence in the infants born to the mothers with ID was higher than in the babies born to the healthy mothers (chi(2) = 11.567, P < 0.005). The ID' prevalence in the infants born to the mothers with IDA was higher than in the babies born to the mothers with LID (chi(2) = 7.356, P < 0.01). (3) The sTfR values of infants born to the mother with ID during pregnancy were increased significantly (P < 0.01); the iron nutritional status did not show any significant difference between babies whose mothers were IDA and LID (P > 0.05). (4) The SF value of maternal venous blood was negatively correlated with the sTfR value of infant (r = -0.7552, P < 0.01).

Conclusions: (1) The anemia of the infants aged 3 - 5 months was correlated with the iron shortage during the fetal stage. (2) The mild iron deficiency in the pregnant women during the second trimester could decrease the iron storage of fetus and then also could affect the iron status of the early infancy and cause anemia.