A lack of sodium in the first two weeks of life can have a major effect on the development of the brains of premature infants. These are the findings of a recent study by doctors at Guy's Hospital in London published in the March edition of the Archives of Disease in Childhood - Foetal and Neonatal Edition.
A team of researchers led by Dr G.B. Haycock assessed the neuro-developmental abilities of 37 children aged between 10 and 13. All had been born prematurely, at or before 33 weeks gestation.
The researchers administered 1 to 1.5 mmol sodium/day to 16 of the children from the fourth to the 14th day after birth (control group), while the remainder received 4 to 5 mmol sodium/day during the same period.
The study showed that the children who had received the sodium supplements immediately after birth outperformed the control group in all neuro-developmental tests, with the difference in their performances in motor function, performance IQ, behaviour as assessed by their parents, and object naming proving statistically significant.
Memory and learning tasks were also handled more adeptly by the supplemented group - they were some 10 per cent better than the control group - although the differences were not statistically significant, except in the area of their learning index scores.
"The most likely explanation for the differences between groups is a significant adverse effect of sodium deficiency on growth and development of the central nervous system. Appropriate steps should be taken to optimise sodium intake of very premature infants during the first two weeks of postnatal life, and to prevent hyponatraemia, in accordance with previously published guidelines," the researchers concluded in the article.