Division of Maternal-Fetal Medicine, Department of Obstetrics, Gynecology and Reproductive Sciences, The Fetal Center at Children's Memorial Hermann Hospital, UT Health - The University of Texas Medical School at Houston, TX, USA.
Ultrasound Obstet Gynecol. 2015 Feb;45(2):175-82. doi: 10.1002/uog.14696.
To determine the risk factors for spontaneous preterm delivery (PTD) or preterm prelabor rupture of membranes (PPROM) at < 34 weeks' gestation after fetoscopic laser surgery for twin-twin transfusion syndrome and to identify the optimal threshold for preoperative cervical length (CL) that indicates a high risk for spontaneous PTD.
This was a secondary analysis of data prospectively collected from 449 patients at three fetal centers. CL measurements were obtained by preoperative transvaginal ultrasound, at a gestational age of 16-26 weeks. The risk factors associated with spontaneous PTD before 34 weeks' gestation were determined using multivariable logistic regression analysis. We excluded patients with dual fetal demise and those with maternal or fetal indications for delivery without PPROM (n = 63). The optimal threshold for cervical length to predict spontaneous PTD before 34 weeks was determined using a receiver-operating characteristics (ROC) curve and Youden index. Additionally, the CL threshold for spontaneous PTD at 2-week intervals between 24 and 34 weeks was determined.
Spontaneous PTD before 34 weeks occurred in 206 (53.4%) of the included patients. Only the preoperative CL was significantly associated with spontaneous PTD. The preoperative CL was normally distributed with a mean of 37.6 ± 10.3 mm (range, 5-66 mm). Maternal age and parity were positively associated, and gestational age at procedure and anterior placenta were negatively associated, with CL on multivariable linear regression analysis. The area under the ROC curve for predicting spontaneous PTD with CL measurements was 0.61 (P = 0.02) and the optimal threshold was 28 mm with a Youden index of 0.19 (sensitivity and specificity of 92% and 27%, respectively). A CL measurement of < 28 mm increased the risk of spontaneous PTD for all gestational age thresholds.
Spontaneous PTD at < 34 weeks' gestation is associated with a preoperative CL of < 28 mm. Preventive strategies should focus on this high-risk group.
确定胎儿镜激光手术治疗双胎输血综合征后妊娠 34 周前自发性早产（PTD）或早产胎膜早破（PPROM）的危险因素，并确定术前宫颈长度（CL）的最佳阈值，以提示 PTD 风险较高。
这是对来自三个胎儿中心的 449 名患者前瞻性收集的数据进行的二次分析。CL 测量在妊娠 16-26 周时通过术前经阴道超声获得。使用多变量逻辑回归分析确定与妊娠 34 周前自发性 PTD 相关的危险因素。我们排除了双胎死亡的患者和无 PPROM 的因母体或胎儿原因需要分娩的患者（n=63）。使用受试者工作特征（ROC）曲线和约登指数确定预测妊娠 34 周前自发性 PTD 的最佳 CL 阈值。此外，还确定了妊娠 24-34 周期间每 2 周间隔的自发性 PTD 的 CL 阈值。
纳入的患者中，有 206 例（53.4%）在妊娠 34 周前发生自发性 PTD。只有术前 CL 与自发性 PTD 显著相关。术前 CL 呈正态分布，平均为 37.6±10.3mm（范围，5-66mm）。多变量线性回归分析显示，产妇年龄和产次呈正相关，而手术时的孕周和前置胎盘呈负相关。CL 预测自发性 PTD 的 ROC 曲线下面积为 0.61（P=0.02），最佳阈值为 28mm，约登指数为 0.19（敏感性和特异性分别为 92%和 27%）。CL 测量值<28mm 增加了所有妊娠周数阈值下自发性 PTD 的风险。
妊娠 34 周前自发性早产与术前 CL<28mm 有关。预防策略应针对这一高危人群。
