Relationship between maternal global nutrient restriction during pregnancy and offspring kidney structure and function: a systematic review of animal studies

Maternal under-nutrition during pregnancy is prevalent across the globe, and the origins of many chronic diseases can be traced back to in utero conditions. This systematic review considers the current evidence in animal models regarding the relationship between maternal global nutrient restriction during pregnancy and offspring kidney structure and function. CINAHL, Cochrane, EMBASE, MEDLINE and Scopus were searched to November 2017. PRISMA guidelines were followed, and articles screened by two independent reviewers. RESULTS:28 studies met the inclusion criteria: 16 studies were on rats, nine on sheep, two on baboons, and one on goats. The majority of the rat studies had maternal global nutrient restriction during pregnancy at 50% of ad libitum, while restriction for sheep and baboon studies ranged from 50-75%. Due to the heterogeneity of outcome measures and the large variation in the age at offspring at follow-up, no meta-analysis was possible. Common outcome measures included kidney weight, nephron number, glomerular size, glomerular filtration rate (GFR), and creatinine clearance. To date, there have been no studies assessing kidney function in large animal models. Most studies were rated as having a high or unknown risk of bias. The current body of evidence in animals suggests that exposure to maternal global nutrient restriction during pregnancy has detrimental effects on offspring kidney structure and function, such as lower kidney weight, lower nephron endowment, larger glomerular size and lower GFR. Further long-term follow-up of studies in large animal models investigating kidney function through to adulthood are warranted.