Secondary analysis of a prospective cohort undergoing serial placental MRIs at two academic tertiary care centers. The population included 316 participants undergoing MRI up to three times throughout gestation. MRI was used to calculate placental volume in milliliters (ml). Placental-mediated adverse pregnancy outcome (cAPO) included preeclampsia with severe features, abnormal antenatal surveillance, and perinatal mortality. Serial measurements were grouped as time point 1 (TP1) <22 weeks, TP2 22 0/7-29 6/7 weeks, and TP3 ≥30 weeks. Mixed effects models compared change in placental volume across gestation between cAPO groups. Association between cAPO and placental volume was determined using logistic regression at each TP with discrimination evaluated using area under receiver operator curve (AUC). Placental volume was then added to known clinical predictive variables and evaluated with test characteristics and calibration.
59 (18.7 %) of 316 participants developed cAPO. Placental volume growth across gestation was slower in the cAPO group (p < 0.001). Placental volume was lower in the cAPO group at all time points, and alone was moderately predictive of cAPO at TP3 (AUC 0.756). Adding placental volume to clinical variables had moderate discrimination at all time points, with strongest test characteristics at TP3 (AUC 0.792) with sensitivity of 77.5 % and specificity of 75.3 % at a predicted probability cutoff of 15 %.
MRI placental volume warrants further study for assessment of placental insufficiency, particularly later in gestation.
方法:对在两个学术三级护理中心接受系列胎盘MRI的前瞻性队列进行二次分析。该人群包括316名参与者,在整个妊娠期间接受MRI多达3次。MRI用于计算以毫升(ml)为单位的胎盘体积。胎盘介导的不良妊娠结局(cAPO)包括具有严重特征的先兆子痫,产前监测异常,和围产期死亡率。连续测量被分组为时间点1(TP1)<22周,TP2220/7-296/7周,TP3≥30周。混合效应模型比较了cAPO组之间妊娠期间胎盘体积的变化。在每个TP使用逻辑回归确定cAPO和胎盘体积之间的关联,并使用接受者操作员曲线下面积(AUC)评估区分性。然后将胎盘体积添加到已知的临床预测变量中并用测试特征和校准进行评估。
结果:316名参与者中有59人(18.7%)出现cAPO。cAPO组整个妊娠期的胎盘体积生长较慢(p<0.001)。cAPO组的胎盘体积在所有时间点都较低,单独在TP3时对cAPO有中度预测(AUC0.756)。将胎盘体积添加到临床变量中,在所有时间点都有适度的区分,在TP3(AUC0.792)具有最强的测试特征,灵敏度为77.5%,特异性为75.3%,预测概率截止为15%。
结论:MRI胎盘体积值得进一步研究以评估胎盘功能不全,尤其是在妊娠后期。