Vitamin A, folate, and iron concentrations in cord and maternal blood of intra-uterine growth retarded and appropriate birth weight babies.

Objectives: (i) To evaluate the relationship between the levels of vitamin A, folate and iron in maternal blood and cord blood from mother-baby pairs who had intra-uterine growth retardation (IUGR) and appropriate birth weight (ABW) for gestational age. (ii) To assess low or marginal levels of vitamin A, folate and iron as risk factors for IUGR.
Design: Retrospective unmatched case-control study.
Setting: Maternidade de Campinas, Universidade Estadual de Campinas, Pontificia Universidade Catolica de Campinas, Hospital Albert Sabin.
Subjects: 356 mother-baby pairs who had IUGR and 356 mother-baby pairs who had ABW for gestational age.
Interventions: Newborns were classified as being IUGR according to the Lubchenco classification. Gestational age of the newborns was evaluated by the Capurro method. Vitamin A, folate, ferritin, and haemoglobin were measured respectively by high performance liquid chromatography (HPLC), radioimmunoassay, immunoenzymetric assay and by the cyanmethaemoglobin method.
Results: The percentages of IUGR babies with abnormal levels of nutritional indices compared with ABW babies were 33.1 vs 14.6 for vitamin A, 25.7 vs 19.9 for red blood cell (RBC) folate, 37.0 vs 21.4 for haemoglobin, but similar for ferritin. The percentages of IUGR mothers with abnormal levels of nutritional indices compared to ABW mothers were similar (1.1 vs 1.4) for vitamin A, and 36.8 vs 32.1 for RBC folate. IUGR mothers were less often anaemic (43.2 vs 50.8), but tended to have higher levels of ferritin (37.6 vs 23.9) compared to ABW mothers.
Conclusions: These results indicate marked differences in cord blood between IUGR and ABW with small differences in maternal levels. They suggest that micronutrient deficiency is the result of being born small rather than vice versa. The high levels of ferritin in IUGR mothers may reflect subclinical maternal infection contributing to IUGR. Maternal micronutrient deficiency is unlikely to be a causative factor for IUGR in this population.
Sponsorship: ODA (Overseas Development Agency), United Kingdom; CNPq (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico), Brazil.