Abstract：
BACKGROUND: Extrauterine growth restriction (EUGR) is common in very-low-birth-weight-infants and may be associated with poor neurodevelopment. The growth velocity of preterm infants is increasing over decades, but the relationship between growth velocity, EUGR, and morbidities of preterm infants remains unknown.
METHODS: A total of 263 infants born between 2012 and 2020, with birthweight <1500 g and gestational age of 24-33 weeks, were included. Birthweight and weight on day of evaluation point (corrected gestational age 36 weeks or discharged, whenever comes first) were converted to age-specific and gender-specific Z-scores and analyzed by multivariable modeling. The average growth velocity was calculated by the exponential model.
RESULTS: Average growth velocity from birth to the evaluation point was 11.8 ± 0.3 g/kg/day. The maximum growth velocity from birth to week 8 postnatal occurred at week 4 postnatal (16.4 ± 0.9 g/kg/day). Infants with smaller birth weight, higher gestational age, and indication of intestinal surgery or those who need more days to achieve full enteral feeding were more favorable to have a weight lower than the 10th centile at the evaluation point. By contrast, most comorbidities of prematurity did not affect either lower age-specific weight Z-scores on the evaluation point or larger change in weight Z-score between birth and evaluation point.
CONCLUSIONS: EUGR was associated with gestational age and birth weight. Infants with moderate-to-severe bronchopulmonary dysplasia, high-grade intraventricular hemorrhage, or retinopathy of prematurity tend to have slower growth velocity at 3-5 weeks postnatal, but these did not contribute to EUGR.
METHODS: A total of 263 infants born between 2012 and 2020, with birthweight <1500 g and gestational age of 24-33 weeks, were included. Birthweight and weight on day of evaluation point (corrected gestational age 36 weeks or discharged, whenever comes first) were converted to age-specific and gender-specific Z-scores and analyzed by multivariable modeling. The average growth velocity was calculated by the exponential model.
RESULTS: Average growth velocity from birth to the evaluation point was 11.8 ± 0.3 g/kg/day. The maximum growth velocity from birth to week 8 postnatal occurred at week 4 postnatal (16.4 ± 0.9 g/kg/day). Infants with smaller birth weight, higher gestational age, and indication of intestinal surgery or those who need more days to achieve full enteral feeding were more favorable to have a weight lower than the 10th centile at the evaluation point. By contrast, most comorbidities of prematurity did not affect either lower age-specific weight Z-scores on the evaluation point or larger change in weight Z-score between birth and evaluation point.
CONCLUSIONS: EUGR was associated with gestational age and birth weight. Infants with moderate-to-severe bronchopulmonary dysplasia, high-grade intraventricular hemorrhage, or retinopathy of prematurity tend to have slower growth velocity at 3-5 weeks postnatal, but these did not contribute to EUGR.
摘要：
背景：宫外生长受限（EUGR）在极低出生体重婴儿中很常见，可能与神经发育不良有关。几十年来，早产儿的生长速度在增加，但是生长速度之间的关系，EUGR,早产儿的发病率仍然未知。
方法：共263名出生在2012年至2020年之间的婴儿，出生体重<1500g，胎龄为24-33周，包括在内。评估点当天的出生体重和体重（校正胎龄36周或出院，每当先到时）转换为年龄特异性和性别特异性Z评分，并通过多变量建模进行分析。通过指数模型计算平均生长速度。
结果：从出生到评价点的平均生长速度为11.8±0.3g/kg/天。从出生到出生后第8周的最大生长速度发生在出生后第4周（16.4±0.9g/kg/天）。出生体重较小的婴儿，胎龄较高,肠道手术的指征或需要更多天数才能实现完全肠内喂养的人更有利于在评估点体重低于10分。相比之下,大多数早产合并症均不影响评估点的特定年龄体重Z评分较低或出生和评估点之间体重Z评分的较大变化.
结论：EUGR与胎龄和出生体重相关。中度至重度支气管肺发育不良的婴儿，高度脑室内出血，或早产儿视网膜病变往往在出生后3-5周生长速度较慢，但这些并不有助于EUGR。
方法：共263名出生在2012年至2020年之间的婴儿，出生体重<1500g，胎龄为24-33周，包括在内。评估点当天的出生体重和体重（校正胎龄36周或出院，每当先到时）转换为年龄特异性和性别特异性Z评分，并通过多变量建模进行分析。通过指数模型计算平均生长速度。
结果：从出生到评价点的平均生长速度为11.8±0.3g/kg/天。从出生到出生后第8周的最大生长速度发生在出生后第4周（16.4±0.9g/kg/天）。出生体重较小的婴儿，胎龄较高,肠道手术的指征或需要更多天数才能实现完全肠内喂养的人更有利于在评估点体重低于10分。相比之下,大多数早产合并症均不影响评估点的特定年龄体重Z评分较低或出生和评估点之间体重Z评分的较大变化.
结论：EUGR与胎龄和出生体重相关。中度至重度支气管肺发育不良的婴儿，高度脑室内出血，或早产儿视网膜病变往往在出生后3-5周生长速度较慢，但这些并不有助于EUGR。
