Ray Joel G, Park Alison L, Fell Deshayne B
Department of Obstetrics and Gynecology, St Michael's Hospital, University of Toronto, Toronto, Ontario, Canada;
Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada; and.
Pediatrics. 2017 Dec;140(6). doi: 10.1542/peds.2017-1881. Epub 2017 Nov 8.
Few researchers have evaluated neonatal mortality in the combined presence of preterm birth (PTB) and small-for-gestational age (SGA) birth weight. None differentiated between infants with and without anomalies, considered births starting at 23 weeks' gestation, or defined SGA at a more pathologic cutpoint less than the fifth percentile.
We completed a population-based cohort study within the province of Ontario, Canada, from 2002 to 2015. Included were 1 676 110 singleton hospital live births of 23 to 42 weeks' gestation. Modified Poisson regression compared rates and relative risks of neonatal mortality among those with (1) preterm birth at 23 to 36 weeks' gestation and concomitant severe small for gestational age (PTB-SGA), (2) PTB at 23 to 36 weeks' gestation without severe SGA, (3) term birth with severe SGA, and each relative to (4) neither. Relative risks were adjusted for maternal age and stratified by several demographic variables.
Relative to a neonatal mortality rate of 0.6 per 1000 term infants without severe SGA, the rate was 2.8 per 1000 among term births with severe SGA (adjusted relative risk [aRR] 4.6; 95% confidence interval [CI] 4.0-5.4), 22.9 per 1000 for PTB without severe SGA (aRR 38.3; 95% CI 35.4-41.4) and 60.0 per 1000 for PTB-SGA (aRR 96.7; 95% CI 85.4-109.5). Stratification by demographic factors showed a persistence of this pattern of neonatal death. Restricting the sample to births at ≥24 weeks' gestation, or newborns without a congenital or chromosomal anomaly, also demonstrated the same pattern.
Methods to detect or prevent PTB or SGA should focus on PTB-SGA, which serves as a useful perinatal surveillance indicator.
很少有研究人员评估早产（PTB）和小于胎龄（SGA）出生体重同时存在时的新生儿死亡率。没有人区分有无异常的婴儿，没有考虑从妊娠23周开始的分娩，也没有在低于第五百分位数的更具病理学意义的切点处定义SGA。
我们于2002年至2015年在加拿大安大略省完成了一项基于人群的队列研究。纳入了1676110例妊娠23至42周的单胎医院活产。改良泊松回归比较了以下人群的新生儿死亡率和相对风险：（1）妊娠23至36周早产并伴有严重小于胎龄（PTB-SGA）的人群；（2）妊娠23至36周早产但无严重SGA的人群；（3）足月产且伴有严重SGA的人群；并将每组与（4）既非早产也非严重SGA的人群进行比较。相对风险根据产妇年龄进行了调整，并按几个人口统计学变量进行了分层。
相对于每1000例无严重SGA的足月婴儿0.6的新生儿死亡率，足月产且伴有严重SGA的人群中该死亡率为每1000例2.8（调整后相对风险[aRR]4.6；95%置信区间[CI]4.0-5.4），无严重SGA的PTB人群中为每1000例22.9（aRR 38.3；95%CI 35.4-41.4），PTB-SGA人群中为每1000例60.0（aRR 96.7；95%CI 85.4-109.5）。按人口统计学因素分层显示这种新生儿死亡模式持续存在。将样本限制为妊娠≥24周的分娩或无先天性或染色体异常的新生儿，也显示出相同的模式。
检测或预防PTB或SGA的方法应侧重于PTB-SGA，它可作为一个有用的围产期监测指标。
