The consequences of anaemia during pregnancy, especially iron (Fe) deficiency anaemia, are serious, with an increased risk of prematurity, developmental delay and perinatal mortality and mobility. It is also considered a significant factor for increased risk of disease later in life. Consequently we have developed a rat model to study the relationship between Fe deficiency anaemia during pregnancy, and only during pregnancy, on post-natal growth development and blood pressure. All animal procedures were conducted in accordance with the UK Animals (Scientific Procedures) Act.

Female Hooded Lister rats were fed a normal diet for 2 weeks following weaning, then a diet with normal (50 mg kg^-1) or deficient (7.5 mg kg^-1) Fe content. Four weeks later, they were mated and continued to term whilst receiving either control (C) or deficient (D) diets. At term, litters were culled to 8 and the remaining pups cross-fostered to control fed dams. All pups were weaned at 19 days onto control diet. Data are presented as means ± S.E.M., n = 18 litters, significance was by Student’s unpaired t test, P ▓le│ 0.05. At birth, pups from deficient dams were significantly smaller (C, 5.7 ± 0.2 g; D, 5.0 ± 0.1 g). Survival rates were greater in the deficient group (C, 97 ± 2% D, 74 ± 10 %). A subset of pups was killed within 18 h of birth, and had a reduced haematocrit (C, 37 ± 1% D, 27 ± 2 %). Males had a significant increase in the relative organ weight (ROW) of the heart (C, 0.56 ± 0.02; D, 0.65 ± 0.03) and a decrease in kidney ROW (C, 1.17 ± 0.04; D, 0.97 ± 0.04). The pups grew normally, although slightly smaller than their normal counterparts. Blood pressure was measured, by the tail cuff method, at 6 weeks. Male pups from Fe-deficient dams had a significantly higher (C, 141 ± 5 mmHg; D, 121 ± 6 mmHg) while females had lower blood pressure than their normal counterparts (C, 125 ± 5 mmHg; D, 103 ± 7 mmHg). There was no significant difference in body or organ weights. The haematocrit was reduced in both males (C, 47 ± 1% D, 45 ± 1 %) and females (C, 46 ± 1% D, 43 ± 1 %). By 10 weeks of age blood pressure in the males from Fe-deficient dams was still higher than that of the normal (C, 139 ± 9 mmHg; D, 165 ± 4 mmHg). In the female group, blood pressure had increased and was now greater than controls (C, 142 ± 4 mmHg; D, 158 ± 2 mmHg). Haematocrit in the males was still lower than in controls (C, 49 ± 1% D, 47 ± 1 %).

The data show, unequivocally, that prenatal nutrition is critical in the development of normal postnatal growth. By cross-fostering the pups, we have taken out possible confounding factors, such as maternal anaemia during lactation. The data suggest altered fluid retention causes a decreased haematocrit with a consequent increase in blood pressure. We are currently testing this hypothesis.

This work was funded by SERAD and the European Union.