目的 研究早产儿纠正月龄6个月内追赶生长的情况，并分析宫外发育迟缓（EUGR）的影响因素。方法 选取在新生儿重症监护病房治疗后出院的，并建立序贯化定期随访档案且有完整随访记录的早产儿321例，按2015年“早产儿保健工作规范”出院后分组随访标准分为低危早产儿组（n=69）和高危早产儿组（n=252）。采用Z评分法对体重、身长和头围进行评估，分析早产儿纠正月龄6个月内追赶生长情况。并采用多因素logistic回归分析探讨6月龄EUGR发生的危险因素。结果 低危组和高危组两组早产儿体重、身长和头围的Z值 < -2（未达追赶生长）的百分比均随纠正月龄增加而逐渐下降，其中低危组早产儿纠正月龄6个月时体重、身长和头围未达追赶生长的比例分别降为1.4%（1/69）、2.9%（2/69）和 1.4%（1/69），高危组早产儿相应的比例为1.2%（3/252）、1.6%（4/252）和3.6%（9/252）。高危组纠正6月龄EUGR发生率高于低危组（28.2% vs 15.9%，P=0.039）。多因素logistic回归分析显示，早产儿纠正6月龄EUGR的危险因素包括多胎（OR=2.68，P=0.010）、出生体重较低（<1 000 g：OR=14.84，P < 0.001；1 000~1 499 g：OR=2.85，P=0.005）、宫内发育迟缓（OR=11.41，P < 0.001），而出生后营养强化可降低EUGR的风险（OR=0.25，P < 0.001）。结论 早产儿多可在纠正月龄6个月内达追赶生长；高危早产儿6月龄EUGR发生率较高；多胎、低出生体重、宫内发育迟缓为早产儿EUGR的危险因素，而出生后合理营养强化可降低早产儿EUGR的发生。

Objective To investigate the catch-up growth of preterm infants within a corrected age of 6 months and the risk factors for extrauterine growth retardation (EUGR). Methods A total of 321 preterm infants who were discharged after treatment in the neonatal intensive care unit and had regular follow-up documents with complete follow-up records were enrolled. According to the Prenatal Health Care Norms in 2015, these infants were divided into low-risk group with 69 infants and high-risk group with 252 infants. The Z-score method was used to evaluate body weight, body length, and head circumference, and the catch-up growth of the preterm infants within a corrected age of 6 months was analyzed. A multivariate logistic regression analysis was performed to identify the risk factors for EUGR at the corrected age of 6 months. Results The percentage of preterm infants with Z scores of body weight, body length, and head circumference of < -2 (not reach the standard for catch-up growth) in both groups decreased gradually with increasing corrected age. At the corrected age of 6 months, the percentages of preterm infants whose body weight, body length, and head circumference did not reach the standard for catch-up growth in the low-risk group were reduced to 1.4% (1/69), 2.9% (2/69), and 1.4% (1/69) respectively, while in the high-risk group, these percentages were reduced to 1.2% (3/252), 1.6% (4/252), and 3.6% (9/252) respectively. The high-risk group had a significantly higher incidence rate of EUGR at the corrected age of 6 months than the low-risk group (28.2% vs 15.9%, P=0.039). The multivariate logistic regression analysis showed that multiple birth (OR=2.68, P=0.010), low birth weight (<1 000 g: OR=14.84, P < 0.001; 1 000-1 499 g: OR=2.85, P=0.005), and intrauterine growth retardation (IUGR) (OR=11.41, P < 0.001) were risk factors for EUGR at the corrected age of 6 months, while nutritional enhancement after birth (OR=0.25, P < 0.001) reduced the risk of EUGR. Conclusions Most preterm infants can achieve catch-up growth at the corrected age of 6 months. High-risk preterm infants have a high incidence rate of EUGR at the corrected age of 6 months. Multiple birth, low birth weight, and IUGR are risk factors for EUGR, while rational nutritional enhancement after birth can reduce the incidence rate of EUGR in preterm infants.