Giapros Vasileios, Drougia Aikaterini, Hotoura Efthalia, Papadopoulou Frederica, Argyropoulou Maria, Andronikou Styliani
Neonatal Intensive Care Unit, University Hospital of Ioannina PO Box 1186, Ioannina 451 10, Greece.
Nephrol Dial Transplant. 2006 Dec;21(12):3422-7. doi: 10.1093/ndt/gfl466. Epub 2006 Aug 25.
Very few data are available on longitudinal renal growth in small for gestational age (SGA) infants born at term. The aim of this prospective study was to estimate comparatively the renal growth in SGA infants and in infants born appropriate for gestational age (AGA) during the first 2 years of life.
The study comprised groups of SGA and AGA infants with a gestational age (GA) of 36-41 weeks. The SGA group was classified into two subgroups of symmetrical and asymmetrical neonates according to the ponderal index. Serial renal ultrasonography (US) was performed at the ages of 41 weeks corrected age [GA (in weeks) plus age after birth (in weeks)] and at 3, 6, 12 and 24 months of chronological age and kidney length (KL) was related to other anthropometric indices.
A total of 312 infants participated in the study out of which 197 were SGA, and a total number of 802 measurements were performed. The symmetrical SGA infants and, to a lesser degree, the asymmetrical SGA infants had smaller kidneys at birth compared with the AGA infants (P < 0.0001 and P < 0.001, respectively). The symmetrical SGA infants had a lower body weight (BW) (P < 0.001, P < 0.01) and crown-heel length (CHL) (P < 0.01, P < 0.05) than controls at the ages of 12 and 24 months of chronological age. The asymmetrical SGA infants had a lower BW (P < 0.01, P < 0.05) than controls at the ages of 12 and 24 months of chronological age. On the contrary, the KL in both SGA groups was not different from that of the AGA infants after the 41st week of corrected age and up to the 2nd year of life.
SGA term infants had shorter KL at birth compared with AGA infants but a similar length from the 3rd to the 24th month of life. Early catch-up kidney growth was observed in both SGA groups and is more prominent in the symmetrical SGA infants. This observation may represent either an accelerated renal maturation process or early compensatory kidney hypertrophy in this group of infants.
关于足月出生的小于胎龄（SGA）婴儿的肾脏纵向生长的数据非常少。这项前瞻性研究的目的是比较评估SGA婴儿和适于胎龄（AGA）婴儿在出生后前2年的肾脏生长情况。
该研究纳入了孕周为36 - 41周的SGA和AGA婴儿组。根据体重指数，SGA组被分为对称型和非对称型新生儿两个亚组。在矫正年龄41周[孕周（周）加上出生后年龄（周）]以及实际年龄3、6、12和24个月时进行系列肾脏超声检查（US），并将肾长（KL）与其他人体测量指标相关联。
共有312名婴儿参与了该研究，其中197名是SGA婴儿，总共进行了802次测量。与AGA婴儿相比，对称型SGA婴儿以及程度稍轻的非对称型SGA婴儿在出生时肾脏较小（分别为P < 0.0001和P < 0.001）。在实际年龄12和24个月时，对称型SGA婴儿的体重（BW）（P < 0.001，P < 0.01）和顶跟长度（CHL）（P < 0.01，P < 0.05）低于对照组。在实际年龄12和24个月时，非对称型SGA婴儿的BW低于对照组（P < 0.01，P < 0.05）。相反，在矫正年龄41周后直至出生后第2年，两个SGA组的KL与AGA婴儿的KL没有差异。
与AGA婴儿相比，足月SGA婴儿出生时KL较短，但在出生后3至24个月时长度相似。在两个SGA组中均观察到早期肾脏追赶生长，且在对称型SGA婴儿中更为显著。这一观察结果可能代表了该组婴儿肾脏成熟过程加速或早期代偿性肾肥大。
