Serum creatinine and creatinine clearance in healthy neonates and prematures during the first 10 days of life

Abstract

Normal serum creatinine (Scr) and creatinine clearance (Ccr) values during the first 10 days of life were obtained in 63 very premature (28-32 weeks of gestation), premature (33-37 weeks) and term infants (38-42 weeks). Scr fell, and Ccr rose less markedly in the very premature infants. Scr was 80 mumol/l on the 1st day of life both in very premature and premature infants, and 77 mumol/l in full-term neonates. After 10 days, Scr was 73, 53 and 35 mumol/l respectively. There was an exponential correlation between Ccr and gestational age, indicating rapid maturation of glomerular function.

Assessment of renal functional maturation and injury in preterm neonates during the first month of life

“…In addition, 24-h urine was collected on days 14, 21, and 28 of life. Spot urine samples (1-2 ml) were obtained on days 7,14,21, and 28 of life. In term neonates, 24-h urine collection commenced 48 h after birth (day 2) and continued until the infant was discharged from the hospital (ϳday 4 of life).…”

“…Furthermore, compared with babies born at term, preterm neonates may demonstrate a slower progression in renal functional maturation after birth (5,14). Creatinine clearance (C Cr ) has been shown to be positively correlated with both gestational age and postnatal age (2, 5, 7-9, 12, 14, 21, 39, 47, 51, 56), while the fractional excretion of sodium (FE Na ) has been shown to be inversely correlated with gestational age (12) and postnatal age (2,12,13,39,47).…”

Factors affecting postnatal changes in serum creatinine in preterm infants with gestational age <32 weeks

“…[1][2][3] However, preterm birth is often associated with gestational diseases affecting placental function and/or maternal renal function. Furthermore, some gestational diseases may also affect fetal glomerular development by inducing intrauterine growth restriction.…”

Preterm Birth and/or Factors that Lead to Preterm Delivery: Effects on the Neonatal Kidney

“…Certainly, both glomerular and tubular function are influenced by gestational age at birth and hence, it is difficult to establish whether the differences in renal function in preterm infants compared to term infants are solely due to underdevelopment of the nephrons or the result of injury in an immature kidney. During the first week after birth, glomerular filtration rate (GFR) is significantly lower in preterm infants compared to term infants [26][27][28] and it is positively correlated with gestational age at birth and postnatal age [29][30][31]. Likewise, creatinine clearance, one of the most commonly used markers of renal function, is positively correlated with both gestational age and postnatal age [20,21,[29][30][31][32][33][34][35][36][37][38][39].…”

“…During the first week after birth, glomerular filtration rate (GFR) is significantly lower in preterm infants compared to term infants [26][27][28] and it is positively correlated with gestational age at birth and postnatal age [29][30][31]. Likewise, creatinine clearance, one of the most commonly used markers of renal function, is positively correlated with both gestational age and postnatal age [20,21,[29][30][31][32][33][34][35][36][37][38][39]. In addition, preterm neonates excrete high amounts of sodium in the early neonatal period compared to term neonates, with the fractional excretion of sodium inversely correlated with gestational age and postnatal age [29,[39][40][41][42][43].…”