Department of Pediatrics, Juntendo University Faculty of Medicine, Hongo, Bunkyo-ku, Tokyo, Japan.
Graduate School of Public Health, St. Luke's International University, Akashi-cho, Chuo-ku, Tokyo, Japan.
JAMA Netw Open. 2021 Oct 1;4(10):e2128555. doi: 10.1001/jamanetworkopen.2021.28555.
The development of neonatology has been associated with improved survival among infants born extremely preterm, and understanding their long-term outcomes is becoming increasingly important. However, there is little information on body mass index (BMI) among these children.
To determine factors associated with BMI at ages 18 months and 36 months among infants born extremely preterm.
DESIGN, SETTING, AND PARTICIPANTS: This retrospective, multicenter cohort study was conducted using data from the Neonatal Research Network Japan database for 8838 infants born at gestational ages 23 to 28 weeks with data on BMI at 18 months and 36 months. Data were analyzed from April 2018 through June 2021.
BMI and BMI z score at ages 18 months and 36 months were regressed with gestational age, intrauterine growth restriction (IUGR) status, and complications during pregnancy and the neonatal period separately by presence of multiple pregnancy and sex.
BMI and BMI z score at ages 18 months and 36 months.
Among 16 791 eligible infants born extremely preterm, 8838 infants were included in the analysis. There were 7089 infants born from single pregnancies (mean [SD] gestational age, 26.0 [1.6] weeks; 3769 [53.2%] boys; mean [SD] birth weight, 847 [228] g) and 1749 infants born from multiple pregnancies (mean [SD] gestational age, 26.3 [1.5] weeks; 903 [51.6%] boys; mean [SD] birth weight, 860 [217] g). In single pregnancies, every week of increased gestational age was associated with an increase in BMI of 0.21 (95% CI, 0.17-0.25) among boys and 0.20 (95% CI, 0.15-0.25) among girls at age 18 months and 0.21 (95% CI, 0.18-0.24) among boys and 0.21 (95% CI, 0.18-0.24) among girls at age 36 months. There was an interaction association between gestational age and IUGR among boys at age 36 months, with a decrease in the change associated with gestational age of 0.12 (95% CI, 0.05-0.19). Every week of increased gestational age in single pregnancies was associated with an increase in BMI z score of 0.14 (95% CI, 0.17-0.21) among boys and 0.17 (95% CI, 0.13-0.21) among girls at age 18 months and 0.19 (95% CI, 0.16-0.22) among boys and 0.17 (95% CI, 0.15-0.20) among girls at age 36 months. Among single pregnancies, IUGR was associated with a decrease in BMI among boys (0.59 [95% CI, 0.23-0.95]) and girls (0.75 [95% CI, 0.39-1.11]) and BMI z score among boys 0.85 [95% CI, 0.25-0.95)] and girls (0.67 [95% CI, 0.36-0.97] at age 18 months and BMI among boys (0.44 [95% CI, 0.17-0.18]) and girls (0.84 [95% CI, 0.55-1.12]) and BMI z score among boys (0.46 [95% CI, 0.21-0.71]) and girls (0.77 [95% CI, 0.53-1.01]) at age 36 months. In multiple pregnancies, IUGR was associated with a decrease in BMI z score at age 36 months among boys (0.26 [95% CI, 0.42-0.89]) and girls (0.29 [95% CI, 0.22-0.79]). In single pregnancies intraventricular hemorrhage (IVH) was associated with a decrease in BMI of 0.47 (95% CI, 0.21-0.73) among boys and 0.42 (95% CI, 0.13-0.71) among girls at age 18 months and 0.53 (95% CI, 0.32-0.74) among boys and 0.31 (95% CI, 0.07-0.54) among girls at age 36 months. IVH was associated with a decrease in BMI z score in single pregnancies of 0.63 (95% CI, 0.20-0.41) among boys and 0.35 (95% CI, 0.12-0.60) among girls at age 18 months and 0.53 (95% CI, 0.34-0.71) among boys and 0.30 (95% CI, 0.11-0.50) among girls at age 36 months. Similar associations were seen in multiple pregnancies.
This study found that gestational age, the presence of IUGR and multiple pregnancy, and IVH complications were associated with infant BMI at ages 18 months and 36 months. These findings suggest that these complicating factors should be considered when setting growth targets and nutrition strategies for infants born extremely preterm.
重要性：新生儿学的发展与出生极早早产儿存活率的提高有关，因此了解他们的长期预后变得越来越重要。然而，关于这些儿童的体重指数（BMI）的信息很少。
目的：确定出生极早早产儿在 18 个月和 36 个月时 BMI 相关因素。
设计、地点和参与者：本回顾性多中心队列研究使用日本新生儿研究网络数据库的数据，对 23 至 28 周妊娠龄且在 18 个月和 36 个月时有 BMI 数据的 8838 名婴儿进行分析。数据于 2018 年 4 月至 2021 年 6 月进行分析。
暴露：分别通过是否存在多胎妊娠和性别，分析妊娠龄、宫内生长受限（IUGR）状态以及妊娠和新生儿期并发症与 18 个月和 36 个月时 BMI 和 BMI z 评分的关系。
主要结果和测量：18 个月和 36 个月时的 BMI 和 BMI z 评分。
结果：在 16791 名极早早产儿中，有 8838 名婴儿纳入分析。7089 名婴儿来自单胎妊娠（平均[SD]妊娠龄 26.0[1.6]周；3769[53.2%]为男孩；平均[SD]出生体重 847[228]g），1749 名婴儿来自多胎妊娠（平均[SD]妊娠龄 26.3[1.5]周；903[51.6%]为男孩；平均[SD]出生体重 860[217]g）。在单胎妊娠中，男孩在 18 个月和 36 个月时，每增加一周的妊娠龄与 BMI 增加 0.21（95%CI，0.17-0.25）和女孩增加 0.20（95%CI，0.15-0.25）相关，而女孩在 18 个月和 36 个月时，每增加一周的妊娠龄与 BMI 增加 0.21（95%CI，0.18-0.24）和女孩增加 0.21（95%CI，0.18-0.24）相关。男孩在 36 个月时，妊娠龄和 IUGR 之间存在交互关联，与妊娠龄相关的变化减少了 0.12（95%CI，0.05-0.19）。单胎妊娠中，每增加一周的妊娠龄与男孩在 18 个月和 36 个月时 BMI z 评分增加 0.14（95%CI，0.17-0.21）和女孩增加 0.17（95%CI，0.13-0.21）相关，而女孩在 18 个月和 36 个月时 BMI z 评分增加 0.19（95%CI，0.16-0.22）和女孩增加 0.17（95%CI，0.15-0.20）相关。在单胎妊娠中，IUGR 与男孩 BMI 降低相关（0.59[95%CI，0.23-0.95]）和女孩 BMI 降低相关（0.75[95%CI，0.39-1.11]），男孩和女孩 BMI z 评分降低 0.85[95%CI，0.25-0.95]和女孩 0.67[95%CI，0.36-0.97]在 18 个月时和男孩 BMI 降低 0.44[95%CI，0.17-0.18]和女孩 BMI 降低 0.84[95%CI，0.55-1.12]在 36 个月时和女孩 BMI z 评分降低 0.46[95%CI，0.21-0.71]和女孩 0.77[95%CI，0.53-1.01]在 36 个月时。在多胎妊娠中，IUGR 与男孩（0.26[95%CI，0.42-0.89]）和女孩（0.29[95%CI，0.22-0.79]）在 36 个月时 BMI z 评分降低相关。在单胎妊娠中，脑室内出血（IVH）与男孩（0.47[95%CI，0.21-0.73]）和女孩（0.42[95%CI，0.13-0.71]）在 18 个月时 BMI 降低相关，与女孩（0.53[95%CI，0.32-0.74]）和女孩（0.31[95%CI，0.07-0.54]）在 36 个月时 BMI 降低相关。IVH 与单胎妊娠中男孩（0.63[95%CI，0.20-0.41]）和女孩（0.35[95%CI，0.12-0.60]）在 18 个月时 BMI z 评分降低相关，与女孩（0.53[95%CI，0.34-0.71]）和女孩（0.30[95%CI，0.11-0.50]）在 36 个月时 BMI z 评分降低相关。多胎妊娠中也存在类似的关联。
结论和相关性：本研究发现，妊娠龄、IUGR 和多胎妊娠以及 IVH 并发症与 18 个月和 36 个月时婴儿的 BMI 相关。这些发现表明，在为极早早产儿设定生长目标和营养策略时，应考虑这些复杂因素。
