Division of Maternal-Fetal Medicine, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.
Obstet Gynecol. 2012 Jan;119(1):21-7. doi: 10.1097/AOG.0b013e31823dc56e.
To estimate and compare the risk of morbid perinatal outcomes in pregnancies identified as small for gestational age (SGA) with customized compared with conventional standards of fetal growth.
Ultrasound-derived estimates of fetal weight were used to generate a fetal growth trajectory (N=7,510). The gestational age at delivery and pathologic and physiologic variables from 5,072 pregnancies were used to calculate a customized threshold for SGA. In a separate analysis of 32,070 pregnancies, rates of morbid outcomes were compared in participants classified as SGA according to a population-based birth weight standard only (SGApop only), a customized standard only (SGAcust only), and both methods (SGAboth).
Eight-hundred seventy-five (2.7%) participants were SGApop only, 1,970 (6.1%) participants were SGAboth, and 609 (1.9%) participants were SGAcust only. The odds ratios of neonatal death in SGApop only and SGAcust only pregnancies were 1.78 (95% confidence interval [CI] 0.2-13.1) and 54.6 (95% CI 29.0-102.8), respectively. Rates of prematurity in the SGApop only and SGAcust only cohorts were 4.8% and 64.5%, respectively. After adjustment for the effect of prematurity, odds ratios of neonatal death in the SGApop only and SGAcust only cohorts were 4.8 (95% CI 0.6-37.0) and 2.9 (95% CI 1.4-6.1), respectively.
After adjustment for confounding stemming from premature delivery, there is little difference in the risk of adverse outcomes between SGAcust only and SGApop only participants. Adoption of customized fetal growth standards into clinical practice may not improve the ability to identify pregnancies with increased risk of perinatal morbidity.
评估并比较通过定制胎儿生长标准（customized standards）和传统胎儿生长标准（conventional standards）识别的小于胎龄儿（small for gestational age，SGA）的围产期不良结局风险。
使用超声估计胎儿体重来生成胎儿生长轨迹（N=7510）。使用 5072 例妊娠的分娩时胎龄和病理生理变量来计算 SGA 的定制阈值。在对 32070 例妊娠的单独分析中，仅根据基于人群的出生体重标准（SGApop only）、仅根据定制标准（SGAcust only）或两种方法（SGAboth）将参与者分类为 SGA 时，比较不良结局的发生率。
875 例（2.7%）参与者为 SGApop only，1970 例（6.1%）参与者为 SGAboth，609 例（1.9%）参与者为 SGAcust only。SGApop only 和 SGAcust only 妊娠的新生儿死亡比值比（odds ratio，OR）分别为 1.78（95%置信区间 [confidence interval，CI]：0.2-13.1）和 54.6（95%CI：29.0-102.8）。SGApop only 和 SGAcust only 队列的早产率分别为 4.8%和 64.5%。在调整早产影响后，SGApop only 和 SGAcust only 队列的新生儿死亡 OR 分别为 4.8（95%CI：0.6-37.0）和 2.9（95%CI：1.4-6.1）。
在调整早产引起的混杂因素后，SGAcust only 和 SGApop only 参与者的不良结局风险几乎没有差异。将定制胎儿生长标准纳入临床实践可能不会提高识别围产期发病率增加风险的能力。
