Blood pressure and kidney size in term newborns with intrauterine growth restriction

Abstract

CONTEXT AND OBJECTIVE: Low birth weight is associated with higher blood pressure in childhood and adulthood. The aim of this study was to investigate the influence of intrauterine growth restriction (IUGR) on newborn systolic blood pressure (SBP). DESIGN AND SETTING: Prospective comparative study at Neonatal and Intensive in Clinical Pediatrics Division, Maternity Hospital in Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo. METHODS: 35 newborns with IUGR and 35 without IUGR were compared. Healthy term newborns without malformations, with Apgar score at fifth minute > 6 were included. Birth weight, kidney weight/birth weight ratio, kidney weight (ultrasound scan), plasma renin activity (PRA) and SBP evolution were analyzed during the first month of life (on 1st, 3rd, 7th and 30th days). RESULTS: SBP evolution, kidney weight/birth weight ratio and PRA did not differ between the two groups. In newborns with IUGR, SBP presented positive correlations with birth weight (r = 0.387 p = 0.026) and BMI (r = 0.412 p = 0.017) on the 7th day of life. Positive correlations with birth weight (r = 0.440 p = 0.01) and birth length (r = 0.386 p = 0.026) were also seen on the 30th day. There was an inverse correlation on the 7th day between SBP and kidney weight/birth weight ratio (r = -0.420 p = 0.014), but this did not persist to the end of the month. CONCLUSIONS: IUGR seems not to have any influence on SBP, PRA or kidney weight among term newborns during their first month of life.

Increased protein intake augments kidney volume and function in healthy infants

“…Kidney growth has been directly correlated with birth weight in small-for-gestational age infants and animals. [34][35][36][37] Although we found a correlation between birth weight and kidney volume in our study, it could be due to a global effect of growth rather than a specific effect directly on the kidney. In fact, the effect of birth weight on kidney size disappears in linear regression models, including the current anthropometrical variables.…”

Strategies to improve the understanding of long-term renal consequences after neonatal acute kidney injury

“…Thus, premature infants <34 wk are at risk for CKD due to lesser number of nephron. Intrauterine growth retardation affects gene expression and nephron endowment, and filtration surface area (12,13) are decreased in animals with intrauterine growth retardation. The timing of the growth restriction may be a key element affecting renal development.…”

“…Research over the past decade has provided substantial data showing that AKI leads to CKD (2)(3)(4)(5)(6)(7)(8). Although the exact mechanisms underlying the progression from AKI to CKD continue to be explored, endothelial damage may play a critical role in outcomes, leading to nephron drop-out, interstitial fibrosis, and, ultimately, CKD (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17). A full review of the data on the link between AKI and CKD in animals and adults is beyond the scope of this article but has recently been performed (5).…”

Consumption of a high-salt diet by ewes during pregnancy alters nephrogenesis in 5-month-old offspring

“…A reduced number of glomeruli, with no other adaptation, leads to a reduced surface area for renal sodium filtration. In addition, a reduced glomerular number may reduce an individual's capacity to excrete a sodium load (Matsuoka et al, 2007) both under basal conditions and when given an acute oral salt load. The compromised capacity to excrete salt may lead to higher renal sodium retention, and subsequently renal-related diseases such as hypertension (Brenner et al, 1988).…”