Predictors of shoulder dystocia at the time of operative vaginal delivery.

BACKGROUND: It remains uncertain whether clinical factors known prior to delivery can predict which women are more likely to experience shoulder dystocia in the setting of operative vaginal delivery. OBJECTIVE: We sought to identify whether shoulder dystocia can be accurately predicted among women undergoing an operative vaginal delivery. STUDY DESIGN: This was a case-control study of women undergoing a low or outlet operative vaginal delivery from 2005 through 2014 in a single tertiary care center. Cases were defined as women who experienced a shoulder dystocia at the time of operative vaginal delivery. Controls consisted of women without a shoulder dystocia at the time of operative vaginal delivery. Variables previously identified to be associated with shoulder dystocia that could be known prior to delivery were abstracted from the medical records. Bivariable analyses and multivariable logistic regression were used to identify factors independently associated with shoulder dystocia. A receiver operating characteristic curve was created to evaluate the predictive value of the model for shoulder dystocia. RESULTS: Of the 4080 women who met inclusion criteria, shoulder dystocia occurred in 162 (4.0%) women. In bivariable analysis, maternal age, parity, body mass index, diabetes, chorioamnionitis, arrest disorder as an indication for an operative vaginal delivery, vacuum use, and estimated fetal weight >4 kg were significantly associated with shoulder dystocia. In multivariable analysis, parity, diabetes, chorioamnionitis, arrest disorder as an indication for operative vaginal delivery, vacuum use, and estimated fetal weight >4 kg remained independently associated with shoulder dystocia. The area under the curve for the generated receiver operating characteristic curve was 0.73 (95% confidence interval, 0.69-0.77), demonstrating only a modest ability to predict shoulder dystocia before performing an operative vaginal delivery. CONCLUSION: While risk factors for shoulder dystocia at the time of operative vaginal delivery can be identified, reliable prediction of shoulder dystocia in this setting cannot be attained.

Predictors of Failed Operative Vaginal Delivery in a Contemporary Obstetric Cohort.

OBJECTIVE: To identify factors associated with failed operative vaginal delivery in contemporary parturients and evaluate whether these factors can be used to accurately predict failed operative vaginal delivery. METHODS: This was a case-control study of women undergoing a trial of operative vaginal delivery from a low or outlet station between 2005 and 2014. Women in the case group were defined as women who had an attempted operative vaginal delivery but ultimately required cesarean delivery. Women in the control group were defined as women who delivered vaginally. Bivariable and multivariable analyses were performed to determine factors that were independently associated with failed operative vaginal delivery. A receiver operating characteristic curve was created and area under the curve calculated to estimate the predictive capacity of these associations. RESULTS: Of 4,352 women who met inclusion criteria, 2,527 underwent an attempt at operative vaginal delivery using forceps and 1,825 using vacuum. Failure occurred in 272 (6.3%). In bivariable analysis, nulliparity, white race, induction of labor, chorioamnionitis, second stage 2 hours or greater, fetal occiput-posterior position, low station at application (compared with outlet), larger estimated fetal weight, and arrest or exhaustion as an indication for operative vaginal delivery (compared with a fetal indication) were significantly associated with a failed operative vaginal delivery. In multivariable analysis, factors that remained independently associated with operative vaginal delivery failure were race-ethnicity, arrest or exhaustion as an indication for operative vaginal delivery, occiput-posterior position, and a low pelvic application. The area under the curve for this regression was 0.74 (95% confidence interval 0.69-0.77) demonstrating less than optimal prediction of operative vaginal delivery failure. CONCLUSION: Risk factors identified before an operative vaginal delivery attempt cannot be used to accurately predict whether an operative vaginal delivery attempt will fail.

A Novel Biomarker Panel Examining Response to Gemcitabine with or without Erlotinib for Pancreatic Cancer Therapy in NCIC Clinical Trials Group PA.3.

PURPOSE: NCIC Clinical Trials Group PA.3 was a randomized control trial that demonstrated improved overall survival (OS) in patients receiving erlotinib in addition to gemcitabine for locally advanced or metastatic pancreatic cancer. Prior to therapy, patients had plasma samples drawn for future study. We sought to identify biomarkers within these samples. EXPERIMENTAL DESIGN: Using the proximity ligation assay (PLA), a probe panel was built from commercially available antibodies for 35 key proteins selected from a global genetic analysis of pancreatic cancers, and used to quantify protein levels in 20 uL of patient plasma. To determine if any of these proteins levels independently associated with OS, univariate and mulitbaraible Cox models were used. In addition, we examined the associations between biomarker expression and disease stage at diagnosis using Fisher's exact test. The correlation between Erlotinib sensitivity and each biomarkers was assessed using a test of interaction between treatment and biomarker. RESULTS AND CONCLUSION: Of the 569 eligible patients, 480 had samples available for study. Samples were randomly allocated into training (251) and validation sets (229). Among all patients, elevated levels of interleukin-8 (IL-8), carcinoembryonic antigen (CEA), hypoxia-inducible factor 1-alpha (HIF-1 alpha), and interleukin-6 were independently associated with lower OS, while IL-8, CEA, platelet-derived growth factor receptor alpha and mucin-1 were associated with metastatic disease. Patients with elevated levels of receptor tyrosine-protein kinase erbB-2 (HER2) expression had improved OS when treated with erlotinib compared to placebo. In conclusion, PLA is a powerful tool for identifying biomarkers from archived, small volume serum samples. These data may be useful to stratify patient outcomes regardless of therapeutic intervention. TRIAL REGISTRATION: ClinicalTrials.gov NCT00040183.