Cutfield Wayne, Ayyavoo Ahila
Department of Pediatric Endocrinology, Liggins Institute, University of Auckland, Auckland, New Zealand.
Department of Pediatrics, G. Kuppuswamy Naidu Memorial Hospital, Coimbatore, Tamil Nadu, 641037, India.
Indian J Pediatr. 2021 Dec;88(12):1235-1240. doi: 10.1007/s12098-021-03897-0. Epub 2021 Aug 17.
'Small for gestational age' (SGA) is an auxological and not an etiological definition that characterizes children born small based upon low-birth-weight and/or birth-length criteria [≥ 2 standard deviations (SD) below the mean for gestational age]. Most SGA children exhibit catch-up growth into the normal range within 6 mo of age. Overall SGA children are 4 cm shorter than expected based upon midparental height and being born SGA is a common cause of adult short stature. Recombinant human growth hormone (rhGH) has been shown to improve adult height by 0.9 SDs and is a safe treatment. Surprisingly, a higher rhGH dose (67 μgm/kg/d) did not lead to a greater adult height than a conventional dose (33 μgm/kg/d). At least 85% of SGA children treated through childhood with rhGH achieve a height within the normal adult range. Other long-term consequences for children born SGA include insulin resistance, abdominal adiposity, dyslipidemia, type 2 diabetes mellitus, and metabolic syndrome. Cross-sectional studies have found reduced insulin sensitivity in the neonatal, childhood, and young adult periods. Increased abdominal fat has been shown in preschool SGA children and is more evident in young adults. Increased adiposity markedly accentuates reduction in insulin sensitivity. Many SGA children have suffered from in utero nutritional restriction that leads to long-term growth restriction and adverse metabolic sequelae.
“小于胎龄儿”（SGA）是一种体格学定义，而非病因学定义，它是根据低出生体重和/或出生身长标准（低于胎龄均值≥2个标准差）来界定出生时体重较轻的儿童。大多数小于胎龄儿在6月龄内会出现追赶生长，达到正常范围。总体而言，小于胎龄儿比根据父母平均身高预期的身高矮4厘米，出生时为小于胎龄儿是成人身材矮小的常见原因。重组人生长激素（rhGH）已被证明可使成人身高提高0.9个标准差，且是一种安全的治疗方法。令人惊讶的是，较高剂量的重组人生长激素（67μg/kg/d）相比传统剂量（33μg/kg/d）并未带来更高的成人身高。至少85%在儿童期接受重组人生长激素治疗的小于胎龄儿身高能达到正常成人范围。小于胎龄儿出生后的其他长期后果包括胰岛素抵抗、腹部肥胖、血脂异常、2型糖尿病和代谢综合征。横断面研究发现，在新生儿期、儿童期和青年期胰岛素敏感性降低。学龄前小于胎龄儿已出现腹部脂肪增加，在青年成人中更为明显。肥胖的增加显著加剧了胰岛素敏感性的降低。许多小于胎龄儿在子宫内经历了营养限制，这导致长期生长受限和不良代谢后遗症。
