Related Experiment Video
Updated: Jul 3, 2026
Fetal Echocardiography and Pulsed-wave Doppler Ultrasound in a Rabbit Model of Intrauterine Growth Restriction
Published on: June 29, 2013
The effects of gestational age and growth restriction on compensatory kidney growth
Aikaterini Drougia1, Vasileios Giapros, Efthalia Hotoura
1Neonatal Intensive Care Unit, University Hospital of Ioannina, Ioannina, Greece.
Insights
Small-for-gestational age (SGA) infants born full-term show normal kidney growth. However, preterm SGA infants experience impaired relative kidney length (RKL) up to two years, indicating potential long-term renal health risks.
Area of Science:
- Pediatric Nephrology
- Neonatology
- Developmental Biology
Background:
- Low birth weight is linked to kidney problems and hypertension later in life.
- Understanding renal growth in infants born small for gestational age (SGA) is crucial for long-term health.
- This study investigates renal development in SGA infants across varied gestational ages and growth retardation degrees.
Purpose of the Study:
- To estimate renal growth in the first two years of life for small-for-gestational age (SGA) infants.
- To compare renal growth in SGA infants with appropriate-for-gestational age (AGA) controls.
- To assess the impact of gestational age and birth weight percentile on renal development in SGA infants.
Main Methods:
- Prospective longitudinal study of 466 infants (243 SGA, 223 AGA).
- Infants classified by gestational age (28-34, 34-36, >36 weeks) and SGA growth retardation (birth weight <3rd or 3rd-10th percentile).
- Serial renal ultrasonography measured kidney length (KL) at corrected ages (36, 40 weeks) and chronological ages (3, 6, 12, 24 months), calculating relative kidney length (RKL).
Main Results:
- In full-term/near-term SGA infants (GA >36 weeks), RKL was similar or higher than AGA controls at 12 and 24 months.
- Preterm SGA infants (GA 34-36 weeks) showed lower RKL than AGA controls after 6 months.
- Preterm SGA infants (GA 28-34 weeks) exhibited significantly lower RKL throughout the study compared to AGA controls.
- Absolute kidney length was more affected in preterm SGA infants with birth weight <3rd percentile.
Conclusions:
- Relative kidney length (RKL) in full-term and near-term SGA infants is comparable to AGA infants.
- Preterm SGA infants (<36 weeks GA) demonstrate impaired RKL up to two years of age.
- Early renal development differences in preterm SGA infants may have long-term implications for kidney health.
Background:
Low birth weight is associated with altered renal development, adult onset hypertension and renal disease. The aim of this prospective longitudinal study was to estimate the renal growth during the first 2 years of life in small-for-gestational age (SGA) infants of varied gestational age (GA) and with differing degrees of growth retardation (GR) at birth. Material and methods. The study included 466 children: SGA, n = 243, and appropriate-for-gestational age (AGA), n = 223, classified according to GA into three groups (28-34, 34-36 and >36 weeks, respectively). The SGA children were also classified according to the degree of GR: birth weight <3rd percentile, and birth weight 3-10th percentiles. Serial renal ultrasonography (US) for kidney length (KL) measurement was performed at the ages of 36 and 40 weeks corrected age and 3, 6, 12 and 24 months of chronological age. The ratios of KL(3) to crown to heel length (CHL), body weight (BW) and body surface area (BSA) were used as estimators of relative kidney length (RKL).
Results:
A total of 1898 measurements were performed. In the full-term and near-term SGA infants (GA >36 weeks), RKL was similar to or even higher than that in AGA controls (P < 0.05 at 12 and 24 months). In two groups of preterm infants (GA 34-36, 28-34 weeks), RKL was lower than in AGA controls either after the first 6 months (GA 34-36 group, P < 0.05) or throughout the study period (GA 28-34 group, P < 0.05). The absolute KL was more severely affected in the preterm babies (GA <36 weeks) with BW <3rd percentile than in those of GA 3rd-10th percentile.
Conclusion:
While in full-term and near-term SGA infants RKL is similar to or even higher than that of AGA infants, in smaller preterm babies (<36 weeks of GA) the RKL is impaired up to the second year of life.
Related Concept Videos
01:18Pharmacokinetics in Geriatric Patients: Effect of Age on Drug Excretion
01:29Acute Kidney Injury III: Clinical Manifestations
01:28Drug Dosing in Renal Diseases: Estimation of Glomerular Filtration Rate Based on Serum Creatinine Concentration
01:17Factors Affecting Renal Clearance: Renal Impairment
One condition associated with renal failure is uremia. Uremia is characterized by impaired glomerular filtration and fluid accumulation in the body. This condition hinders the renal clearance of drugs, resulting in drug accumulation and potential...
01:25Chronic Kidney Disease I: Introduction
01:25Drug Dosing in Renal Diseases: Dose Adjustments Based on Drug Clearance and Elimination Rate Constant