Schwartz Nadav, Sammel Mary D, Leite Rita, Parry Samuel
Department of Obstetrics and Gynecology, Maternal and Child Health Research Program, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA.
Department of Biostatistics and Epidemiology, Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA.
Am J Obstet Gynecol. 2014 Sep;211(3):253.e1-8. doi: 10.1016/j.ajog.2014.02.033. Epub 2014 Mar 5.
The objective of the study was to combine early, direct assessment of the placenta with indirect markers of placental development to identify pregnancies at greatest risk of delivering small-for-gestational age infants (SGA10).
We prospectively collected 3-dimensional ultrasound volume sets, uterine artery pulsatility index, and maternal serum of singleton pregnancies at 11-14 weeks. Placental volume (PV), quotient (placental quotient [PQ] = PV/gestational age), mean placental diameter (MPD) and chorionic diameters, and the placental morphology index (PMI = MPD/PQ and adjusts the lateral placental dimensions for quotient) were measured offline. Maternal serum was assayed for placental growth factor and placental protein-13. These variables were evaluated as predictors of SGA10.
Of the 578 pregnancies included in the study, 56 (9.7%) delivered SGA10. SGA10 pregnancies had a significantly smaller PV, PQ, MPD, and mean placental diameter and higher PMI compared with normal pregnancies (P < .001 for each). Each placental measure remained significantly associated with SGA10 after adjusting for confounders and significantly improved the performance of the model using clinical variables alone (P < .04 for each) with adjusted areas under the curve ranging from 0.71 to 0.74. Uterine artery pulsatility index did not remain significantly associated with SGA10 after adjusting for confounders (P = .06). Placental growth factor was significantly lower in SGA10 pregnancies (P = .02) and remained significant in adjusted models but failed to significantly improve the predictive performance of the models as measured by area under the curve (P > .3). Placental protein-13 was not associated with SGA10 (P = .99).
Direct assessment of placental size and shape with 3-dimensional ultrasound can serve as the foundation upon which to build a multivariable model for the early prediction of SGA.
本研究的目的是将胎盘的早期直接评估与胎盘发育的间接标志物相结合，以识别分娩小于胎龄儿（SGA10）风险最高的妊娠。
我们前瞻性地收集了11至14周单胎妊娠的三维超声容积数据集、子宫动脉搏动指数和母体血清。离线测量胎盘体积（PV）、商数（胎盘商数[PQ]=PV/孕周）、平均胎盘直径（MPD）和绒毛膜直径，以及胎盘形态指数（PMI=MPD/PQ，并根据商数调整胎盘横向尺寸）。检测母体血清中的胎盘生长因子和胎盘蛋白-13。评估这些变量作为SGA10的预测指标。
本研究纳入的578例妊娠中，56例（9.7%）分娩SGA10。与正常妊娠相比，SGA10妊娠的PV、PQ、MPD和平均胎盘直径显著更小，PMI更高（每项P<.001）。在调整混杂因素后，每项胎盘测量指标仍与SGA10显著相关，并显著改善了仅使用临床变量的模型性能（每项P<.04），调整后的曲线下面积范围为0.71至0.74。调整混杂因素后，子宫动脉搏动指数与SGA10不再显著相关（P=.06）。SGA10妊娠的胎盘生长因子显著更低（P=.02），在调整模型中仍具有显著性，但未能显著改善以曲线下面积衡量的模型预测性能（P>.3）。胎盘蛋白-13与SGA10无关（P=.99）。
用三维超声直接评估胎盘大小和形状可作为构建SGA早期预测多变量模型的基础。
