Glomerular filtration rate in the preterm infant: the relation to gestational and postnatal age

Abstract

In 41 preterm neonates with a gestational age (GA) varying from 27 to 36 weeks, glomerular filtration rate (GFR) was measured by means of the continuous inulin infusion technique. The reliability of the technique was confirmed. During postnatal development GFR was found to increase in two ways: firstly, an increase with advancing gestational age, associated with the increase in body weight (BW) [GFR (ml/min) = 0.15 X GA-3.20, r = 0.48, P = 0.0048]; secondly, a postnatal increase, being independent from increment in BW. An increase in GFR (ml/min.kg) from 0.88 +/- 0.23 to 1.18 +/- 0.28 was observed between day 4 and day 11 postnatally (P less than 0.008). This latter increase is probably associated with changes in renal haemodynamics. No significant influence of artificial ventilation on GFR could be demonstrated in preterm neonates.

Renal Side Effects of Non-Steroidal Anti-Inflammatory Drugs in Neonates

“…Respiratory distress syndrome, a low Apgar score and postnatal ibuprofen treatment to induce closure of a patent ductus arteriosus were identified as additional independent risk factors [5]. These epidemiologic observations are in line with other cohorts reported in literature and confirm the multifactorial origin of acute renal impairment in newborns [6,7,8,9]. …”

“…In term neonates, serum creatinaemia decreases rapidly to reach neonatal levels of 0.4 mg/dL by 1 or 2 weeks of postnatal age, while in very preterm neonates there is a transient increase in creatinaemia with a peak on day 3–4 of postnatal life with a subsequent progressive decrease over the next 3 to 4 weeks. This transient increase is a least in part due to passive renal tubular ‘back-leak’ across renal tubular cells lines, making creatinaemia an unreliable marker of glomerular filtration in early life while in adults there is a small net secretion of creatinine so that creatinine clearance is very close to glomerular filtration rate [6,7,8,27]. …”

Reference ranges for plasma cystatin C and creatinine measurements in premature infants, neonates, and older children

“…16 27 From 20 weeks of gestation, kidney weight and body weight have a linear relation to gestational age and body surface area 28…”

Kadar Cystatin-C Serum Sebagai Penanda Fungsi Ginjal Bayi Prematur

“…Bayi prematur mempunyai hubungan linier positif antara usia kehamilan dan berat badan. 15 Pada bayi prematur, terjadinya defisit nefron disertai imaturitas glomerulus dan tubulus menyebabkan fungsi filtrasi dan reabsorpsi terganggu, sehingga mempunyai laju filtrasi glomerulus (LFG) yang lebih rendah dibandingkan dengan bayi cukup bulan. 16,17 Kadar cystatin-C serum rerata subjek penelitian kami didapatkan pada jenis kelamin laki-laki 1,68 mg/L dan perempuan 1,67 mg/L.…”

“…Terdapatnya hubungan linier antara berat badan dan berat ginjal serta usia kehamilan pada bayi prematur dipertimbangkan menjadi salah satu hal yang dapat menjelaskannya. 15 Pada kelahiran prematur, terdapat anggapan terjadi peningkatan reabsorpsi kreatinin akibat imaturitas ginjal. Bayi prematur dengan berat badan lahir yang semakin rendah, maka berat ginjal akan semakin kecil dan mempunyai ukuran panjang tubulus yang lebih kecil, hal tersebut menyebabkan proporsi reabsorpsi berbagai protein termasuk kreatinin akan berkurang sehingga kadarnya akan meningkat dalam sirkulasi.…”