The amount of salt a woman consumes while pregnant may affect her baby's kidney development, according to a new study.
The research finds that either too much or too little, salt intake during pregnancy can have an adverse effect on the prenatal development of the offspring's kidneys.
The consequence of such disturbance can lead to high blood pressure in later years.
Previous research has linked high blood pressure with a low nephron number, critical because the nephron is the basic structural and functional unit of the kidney.
Researchers at the University of Heidelberg and the University of Aarhus, Aarhus, DK fed Sprague-Dawley rats with low, intermediate or high sodium diets during pregnancy and lactation.
The litters were standardized to identical size at birth with 1:1 male to female ratio. The offspring were separated from their mothers at four weeks of age and subsequently received the intermediate sodium diet.
The animals had free access to water and food and their body weight, food and water consumption were monitored weekly.
The kidney structure was assessed at postnatal weeks 1 and 12, and the expression of proteins known to be involved in kidney development were examined at birth and 1 week of age.
Blood pressure was measured by telemetry in male offspring between the ages of two and nine months.
The researchers found that the number of glomeruli (the main structural unit of the kidney) during weeks 1-12 was significantly lower, and the measured blood pressure for males after the fifth month was higher in offspring of mothers on high- or low- compared with intermediate-sodium diet.
The above findings indicate that both too low and too high maternal salt intakes retard development of new glomeruli, resulting in a nephron deficit.
The study is published in the online edition of the American Journal of Physiology-Renal Physiology.