Department of Obstetrics and Gynecology, University of North Carolina School of Medicine, Chapel Hill, NC, United States.
Department of Obstetrics and Gynecology, Medical College of Wisconsin, Milwaukee, WI, United States.
Placenta. 2017 Nov;59:9-12. doi: 10.1016/j.placenta.2017.09.001. Epub 2017 Sep 5.
Previous studies have shown that pregnancies complicated by placentas with an isolated single umbilical artery (iSUA) are at increased risk for small-for-gestational-age (SGA) births. The etiology of SGA in this population, however, remains unknown.
The primary objective of this study was to evaluate whether placental abnormalities in pregnancies with SGA births differ according to the presence of iSUA.
This was an observational study of all women with pathologic examination of the placenta after delivering a non-anomalous, singleton SGA neonate between January 2009 and August 2015. SGA was defined as birthweight less than 10th percentile for gestational age. Women were categorized according to whether they had an iSUA or a three-vessel cord. The following placental pathologies were compared between the groups using bivariable and multivariable analyses: SGA placenta, maternal vascular malperfusion, high grade fetal vascular malperfusion, and chronic villitis.
1833 women were included in the analysis: 34 with iSUA and 1799 with three-vessel cord. More than 85% of women in both groups had at least one placental abnormality. After adjusting for nulliparity and neonatal gender, the presence of iSUA was associated with increased odds of high grade fetal vascular malperfusion (adjusted odds ratio 2.8, 95% confidence interval 1.1-7.5) and decreased odds of maternal vascular malperfusion (adjusted odds ratio 0.2, 95% confidence interval 0.1-0.9). There was no significant association with other pathologic findings.
Pathologic placental findings associated with SGA birth differed based on umbilical cord composition. The presence of iSUA in an SGA birth was associated with a higher odds of high grade fetal vascular malperfusion abnormalities and lower odds of maternal vascular malperfusion abnormalities, compared to SGA birth with a 3VC.
先前的研究表明，伴有孤立性单脐动脉（iSUA）的胎盘妊娠发生胎儿生长受限（SGA）的风险增加。然而，该人群中 SGA 的病因尚不清楚。
本研究的主要目的是评估 SGA 出生的胎盘异常是否因 iSUA 的存在而有所不同。
这是一项观察性研究，纳入了 2009 年 1 月至 2015 年 8 月间所有经病理检查证实胎盘存在异常且分娩出非畸形、单胎 SGA 新生儿的孕妇。SGA 定义为出生体重低于胎龄第 10 百分位数。根据是否存在 iSUA 或三血管脐带，将孕妇分为两组。采用双变量和多变量分析比较两组间的以下胎盘病变：SGA 胎盘、母体血管灌注不良、重度胎儿血管灌注不良和慢性绒毛膜炎。
共有 1833 名孕妇纳入分析：34 名存在 iSUA，1799 名存在三血管脐带。两组中超过 85%的孕妇至少存在一种胎盘异常。调整初产妇和新生儿性别后，iSUA 的存在与重度胎儿血管灌注不良的发生风险增加相关（校正比值比 2.8，95%置信区间 1.1-7.5），与母体血管灌注不良的发生风险降低相关（校正比值比 0.2，95%置信区间 0.1-0.9）。与其他病理发现无显著相关性。
与 SGA 出生相关的胎盘病理发现因脐带组成而异。与 SGA 出生时存在三血管脐带相比，iSUA 的存在与重度胎儿血管灌注不良异常的发生风险增加相关，与母体血管灌注不良异常的发生风险降低相关。
