Marrs Caroline C, Mendez-Figueroa Hector, Hammad Ibrahim A, Chauhan Suneet P
Division of Maternal-Fetal Medicine, Department of Obstetrics, Gynecology, and Reproductive Sciences, UT Health Science Center at Houston, Houston, Texas.
Department of Obstetrics-Gynecology, Eastern Virginia Medical School, Norfolk, Virginia.
Am J Perinatol. 2015 Nov;32(13):1251-6. doi: 10.1055/s-0035-1552939. Epub 2015 May 29.
The objective of this study was to determine the morbidity of preterm small for gestational age (SGA) infants compared with appropriate for GA (AGA).
This is a secondary analysis of the randomized trial evaluating magnesium sulfate for the prevention of cerebral palsy (CP). We compared outcomes of preterm (< 37 weeks) nonanomalous infants who were SGA (birth weight < 10% for GA) versus AGA (birth weight 10-89% for GA). We compared (1) the parent trial primary outcome, a composite of stillbirth, infant death by 1 year of age, or moderate to severe CP at 2 years of age and (2) composite neonatal morbidity (CNM).
Of the 1,948 infants who met inclusion criteria, 95% were AGA and 5% were SGA. The primary outcome was similar (10 and 15%, p = 0.08), as was the CNM (24 and 25%, p = 0.89). Sample size calculations indicate that detection of a one-third higher rate of CNM among SGA compared with AGA infants requires more than 93,900 preterm births; for a one-third difference in moderate to severe CP, more than 1.4 million infants.
Owing to the prohibitive sample size required, ascertaining a difference in sequela between preterm SGA and AGA infants is possibly unverifiable.
本研究的目的是确定小于胎龄（SGA）的早产婴儿与适于胎龄（AGA）婴儿相比的发病率。
这是一项对评估硫酸镁预防脑瘫（CP）的随机试验的二次分析。我们比较了早产（<37周）非畸形SGA婴儿（出生体重<GA的10%）与AGA婴儿（出生体重为GA的10 - 89%）的结局。我们比较了（1）母试验的主要结局，即死产、1岁时婴儿死亡或2岁时中度至重度CP的综合情况，以及（2）综合新生儿发病率（CNM）。
在1948名符合纳入标准的婴儿中，95%为AGA，5%为SGA。主要结局相似（分别为10%和15%，p = 0.08），CNM也相似（分别为24%和25%，p = 0.89）。样本量计算表明，要检测出SGA婴儿的CNM发生率比AGA婴儿高三分之一，需要超过93900例早产；要检测出中度至重度CP有三分之一的差异，需要超过140万例婴儿。
由于所需样本量过高，确定早产SGA婴儿和AGA婴儿后遗症之间的差异可能无法得到验证。
