Abstract: Objective　To investigate the effect of early nutritional strategy adjustment on the incidence of extrauterine growth retardation (EUGR) in extremely premature infants and analyze its risk factors. Methods　It was a prospective observational cohort study. Extremely premature infants under 32 weeks of gestational age who were delivered in the obstetric department of Guangdong Women and Children Hospital between January 1, 2018 and December 31, 2019 were selected. They were divided into a control group and an intervention group before and after adjustment of nutrition strategies. The clinical data of the two groups were collected, including general information, enteral nutrition, and complications. The difference in the incidence of EUGR was compared between the two groups. Multivariate logistic regression analysis was used to analyze the high-risk factors of EUGR in extremely premature infants. Independent sample t test, χ² test, and rank sum test were used for comparison. Results　A total of 356 premature infants eligible for the study were included in the two groups, including 177 cases in the control group and 179 cases in the intervention group. In the control group, there were 114 males and 63 females, with a gestational age of (30.15±1.39) weeks; in the intervention group, there were 110 males and 69 females, with a gestational age of (29.83±1.33) weeks. There were no statistically significant differences in the gender, birth weight, cesarean section rate, small for gestational age rate, asphyxia rate, prenatal glucocorticoid use rate, multiple pregnancy rate, and maternal hypertension rate during pregnancy between the two groups (all P>0.05). The gestational age of the intervention group [(29.83±1.33) weeks] and the control group [(30.15±1.39) weeks] were significantly different (P<0.05). The time of starting enteral feeding [0.5 (0.5, 28.0) h], total enteral feeding time [(28.12±11.76) d], intravenous nutrition time [22 (14, 30) d], time of birth weight recovery [(7.58±5.76) d], and time of achieving sufficient intestinal heat accumulation [(22.59±9.23) d] in the intervention group were shorter than those in the control group [18.0 (0.5, 68.0) h, (32.29±14.02) d, 26 (18, 35) d, (10.73±7.35) d, and (28.64±12.17) d], with statistically significant differences (all P<0.05). The fasting time in the intervention group [(6.16±6.02) d] was less than that in the control group [(8.19±6.98) d], and the amino acid content 1 week after birth, total amino acid content during hospitalization, calories per week, and growth rate of body mass in the intervention group [(11.74±3.67) g/kg, (45.40±34.99) g/kg, (360.03±124.31) kcal/kg, and (21.04±5.71) g/d] were higher than those in the control group [(10.72±2.81) g/kg, (39.22±18.00) g/kg, (312.51±79.82) kcal/kg, and (19.12±5.52) g/d], with statistically significant differences (all P<0.05). The incidence of EUGR in the intervention group was 69.3% (124/179), which was lower than that in the control group [81.4% (144/177)], with a statistically significant difference (P<0.05). Multivariate regression analysis model showed that birth weight (OR=1.980, 95%CI 1.113-3.580, P=0.012), fasting time (OR=1.096, 95%CI 1.006-1.194, P=0.036), total amino acid content during hospitalization (OR=1.087, 95%CI 1.014-1.165, P=0.018) were the high-risk factors for EUGR. Conclusions　The incidence of EUGR in extremely premature infants can be reduced by adopting early intensified nutrition strategies. The incidence of EUGR can be reduced by increasing the total amino acids in parenteral nutrition and adjusting nutrition strategies according to daily weight gain.

Key words: Early nutritional strategies, Extremely premature infants, Extrauterine growth retardation, Risk factors

摘要： 目的　比较早期营养策略调整对极早产儿宫外生长发育迟缓（EUGR）发生率的影响并分析其高危因素。方法　本研究为前瞻观察性队列研究，纳入2018年1月1日至2019年12月31日在广东省妇幼保健院产科娩出的胎龄在32周以下的早产儿，按营养策略调整前后分对照组和干预组，收集两组一般情况、肠内外营养情况、并发症等临床资料，比较两组EUGR发生率差异，并采用多因素logistic回归分析分析极早产儿发生EUGR的高危因素。采用独立样本t检验、χ²检验、秩和检验进行比较。结果　两组共纳入符合研究条件的早产儿356例，对照组177例，干预组179例。对照组男114例、女63例，胎龄（30.15±1.39）周；干预组男110例、女69例，胎龄（29.83±1.33）周。两组性别、出生体质量、剖宫产率、小于胎龄儿率、窒息率、产前糖皮质激素使用率、多胎妊娠率、母亲妊娠期高血压率比较，差异均无统计学意义（均P>0.05）；干预组胎龄［（29.83±1.33）周］与对照组［（30.15±1.39）周］比较，差异有统计学意义（P<0.05）。干预组开始肠内喂养时间［0.5（0.5，28.0）h］、全肠内喂养时间［（28.12±11.76）d］、静脉营养天数［22（14，30）d］、恢复出生体质量时间［（7.58±5.76）d］、达到足量肠内热卡时间［（22.59±9.23）d］均短于对照组［18.0（0.5，68.0）h、（32.29±14.02）d、26（18，35）d、（10.73±7.35）d、（28.64±12.17）d］，差异均有统计学意义（均P<0.05）；干预组禁食天数［（6.16±6.02）d］少于对照组［（8.19±6.98）d］，干预组生后1周氨基酸量和住院期间氨基酸总量、1周热卡量、体质量增长速度［（11.74±3.67）g/kg、（45.40±34.99）g/kg、（360.03±124.31）kcal/kg、（21.04±5.71）g/d］均高于对照组［（10.72±2.81）g/kg、（39.22±18.00）g/kg、（312.51±79.82）kcal/kg、（19.12±5.52）g/d］，差异均有统计学意义（均P<0.05）。干预组极早产儿EUGR发生率为69.3%（124/179），低于对照组81.4%（144/177），差异有统计学意义（P<0.05）。多因素回归分析模型显示出生体质量（OR=1.980，95%CI 1.113～3.580，P=0.012）、禁食天数（OR=1.096，95%CI 1.006～1.194，P=0.036）、住院期间总氨基酸量（OR=1.087，95%CI 1.014～1.165，P=0.018）是EUGR发生的高危因素。结论　早期实行积极营养策略可以降低极早产儿EUGR发生率，增加静脉营养中氨基酸的总量和根据每日体质量增长注意营养策略调整有可能降低EUGR的发生。

关键词: 早期营养策略, 极早产儿, 宫外发育生长迟缓, 高危因素