The consumption of alcohol during pregnancy negatively affects the child’s kidney function, some years after birth, concluded a study developed within the Epidemiology Research Unit (EPIUnit) of the Instituto de Saúde Pública da Universidade do Porto (ISPUP). The study found that this association is significant in children who, during childhood, are overweight or obese.
The research, published in the Pediatric Nephrology journal, showed, for the first time, that children who are exposed to alcohol in the womb have a worse kidney function during childhood. As explained by Liane Correia Costa, the first author of the work, coordinated by Ana Azevedo, “we knew, through animal models, that alcohol consumption during pregnancy affects the development of the fetus’ kidney, leading to a decrease in the total number of nephrons, the functional unit of the kidney. However, studies that showed this association in humans were lacking and, with this work, we managed to do it”.
The article explored the possibility that there are factors related to the child that could influence the association found between alcohol intake during pregnancy and renal malfunction. The relationship was found to be stronger and only significant among children who are overweight or obese.
“Children who were exposed to alcohol while still in the womb have fewer nephrons, the functional units that filter blood in the kidney. These children, who already have a lower number of nephrons, if they develop excess weight during childhood, or later, will overload their kidneys, which will have to filter a larger volume of blood, corresponding to the their greater body mass. This filtration overload that is imposed on the kidney, in the long run, conditions kidney changes and leads to their malfunctioning”, says the researcher.
To reach these results, the study’s authors analyzed data on the renal function of 1093 children, aged 7, belonging to the Generation XXI cohort – a longitudinal study that has followed, since 2005, about 8600 participants who were born in maternity hospitals in the Metropolitan Area of Porto – and used information on the mother’s reported consumption of alcohol (type of drink, amount and frequency of intake).
Alcohol should be avoided in any quantity and throughout pregnancy
The study concluded that 13% of the mothers of children participating in the study consumed alcohol during pregnancy. Further, the negative effect on the child’s kidney increased as the amount of alcohol ingested increased. “Taking into account the harmful effects found, the recommendation must be that alcohol should be avoided, in any quantity and throughout pregnancy”, stresses Liane Correia Costa.
For the researcher, this study seems to reinforce that “alcohol interferes with the formation of nephrons and acts as a vulnerability factor in the functioning of the kidney. When this factor is added to the presence of excess weight in children, the risk of progressing to chronic kidney disease is significantly higher. Thus, the recognition of alcohol as a potentially modifiable risk factor during pregnancy, should put in place a reinforcement of strategies to raise the population’s awareness of these risks. Additionally, investing in strategies that aim to prevent overweight and obesity in children is particularly important”.
The article is entitled Prenatal alcohol exposure affects renal function in overweight schoolchildren: birth cohort analysis. The researchers Franz Schaefer, Alberto Caldas Afonso, Sofia Correia, João Tiago Guimarães, António Guerra and Henrique Barros also participated in the work.
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