BCNatal-Barcelona Center for Maternal-Fetal and Neonatal Medicine (Hospital Clínic and Hospital Sant Joan de Deu), Institut Clínic de Ginecología, Obstetrícia I Neonatología, Fetal i+D Fetal Medicine Research Center, Institut d'Investigacions Biomèdiques August Pi I Sunyer, University of Barcelona, Barcelona, Spain; Centre for Biomedical Research on Rare Diseases, Barcelona, Spain.
BCNatal-Barcelona Center for Maternal-Fetal and Neonatal Medicine (Hospital Clínic and Hospital Sant Joan de Deu), Institut Clínic de Ginecología, Obstetrícia I Neonatología, Fetal i+D Fetal Medicine Research Center, Institut d'Investigacions Biomèdiques August Pi I Sunyer, University of Barcelona, Barcelona, Spain.
Am J Obstet Gynecol. 2020 Sep;223(3):421.e1-421.e14. doi: 10.1016/j.ajog.2020.02.049. Epub 2020 Mar 5.
Early spontaneous preterm delivery is often associated with microbial invasion of the amniotic cavity and/or intraamniotic inflammation.
The objective of the study was to develop and validate clinically feasible multivariable prediction models of spontaneous delivery within 7 days and microbial invasion of the amniotic cavity in women admitted with diagnose of preterm labor and intact membranes below 34 weeks.
We used data from a cohort of women admitted from 2012 to 2018 with diagnosis of preterm labor below 34 weeks who had undergone amniocentesis to rule out microbial invasion of the amniotic cavity. The main outcome was spontaneous delivery within 7 days from admission. The secondary outcome was microbial invasion of the amniotic cavity, defined by a positive culture and/or 16S ribosomal RNA gene in the amniotic fluid. The sample (n = 358) was divided into derivation (2012-2016) and validation cohorts (2017-2018). Logistic regression models using a stepwise selection of variables were developed for the outcomes evaluated. We explored as predictive variables ultrasound cervical length measurement at admission, maternal C-reactive protein, gestational age, amniotic fluid glucose, and interleukin-6 (expressed as log units). Models were developed in the derivation cohort and applied to the validation cohort and diagnostic performance was calculated.
The derivation cohort included 263 women and the validation cohort 95 women. One hundred five of the women (39%, 105 of 268) spontaneously delivered in the following 7 days and 68 (19%, 68 of 358) had microbial invasion of the amniotic cavity. For spontaneous delivery within 7 days after admission, 4 predictors were identified: cervical length at admission, gestational age, amniotic fluid glucose, and interleukin-6. The diagnostic performance of the model was assessed in the validation cohort using the receiver operating characteristic curve and showed an area under curve of 0.86 (95% confidence interval, 0.77-0.95) with a detection rate of spontaneous delivery within 7 days of 87%, a false-positive rate of 33%, a negative predictive value of 80%, and a negative likelihood ratio of 0.1908. For microbial invasion of the amniotic cavity, 2 independent predictors of the amniotic cavity were identified: amniotic fluid glucose and maternal C-reactive protein. The receiver operating characteristic curve and an area under curve in the validation cohort was 0.83 (95% confidence interval, 0.70-0.96) with a detection rate of 76%, a false-positive rate of 8%, a negative predictive value of 93%, and a negative likelihood ratio of 0.2591.
In women with preterm labor, we propose 2 clinically feasible prediction models to classify as low vs high risk of spontaneous delivery within 7 days and of microbial invasion of the amniotic cavity. The models showed a high diagnostic performance and could be of value to optimize clinical management.
早期自发性早产常与羊水腔微生物入侵和/或羊膜内炎症有关。
本研究旨在为孕 34 周前诊断为早产且胎膜完整的孕妇建立并验证一种可用于预测 7 天内自发性早产和微生物性羊膜腔感染的临床可行的多变量预测模型。
我们使用了 2012 年至 2018 年期间因早产入院且接受了羊膜穿刺术以排除微生物性羊膜腔感染的孕妇队列数据。主要结局是入院后 7 天内的自发性早产。次要结局是微生物性羊膜腔感染，定义为羊水培养阳性和/或 16S 核糖体 RNA 基因阳性。样本（n=358）分为推导队列（2012-2016 年）和验证队列（2017-2018 年）。使用逐步选择变量的逻辑回归模型来建立用于评估的结局预测模型。我们将入院时超声宫颈长度测量、母体 C 反应蛋白、孕龄、羊水葡萄糖和白细胞介素-6（以对数单位表示）作为预测变量进行了探索。在推导队列中建立了模型，并应用于验证队列，并计算了诊断性能。
推导队列包括 263 名女性，验证队列包括 95 名女性。268 名女性中有 105 名（39%，105/268）在接下来的 7 天内自然分娩，358 名女性中有 68 名（19%，68/358）发生微生物性羊膜腔感染。对于入院后 7 天内的自发性早产，确定了 4 个预测因素：入院时的宫颈长度、孕龄、羊水葡萄糖和白细胞介素-6。使用受试者工作特征曲线评估模型在验证队列中的诊断性能，曲线下面积为 0.86（95%置信区间，0.77-0.95），7 天内自发性早产的检出率为 87%，假阳性率为 33%，阴性预测值为 80%，阴性似然比为 0.1908。对于微生物性羊膜腔感染，确定了 2 个与羊膜腔相关的独立预测因素：羊水葡萄糖和母体 C 反应蛋白。验证队列的受试者工作特征曲线和曲线下面积为 0.83（95%置信区间，0.70-0.96），检出率为 76%，假阳性率为 8%，阴性预测值为 93%，阴性似然比为 0.2591。
对于患有早产的孕妇，我们提出了 2 种具有临床可行性的预测模型，用于对 7 天内自发性早产和微生物性羊膜腔感染的低风险和高风险进行分类。这些模型表现出了较高的诊断性能，可能对优化临床管理具有价值。
