has been reviewed by the Editorial Board and by special expert referees. Although it is judged not acceptable for publication in Obstetrics & Gynecology in its present form, we would be willing to give further consideration to a revised version.If you wish to consider revising your manuscript, you will first need to study carefully the enclosed reports submitted by the referees and editors. Each point raised requires a response, by either revising your manuscript or making a clear and convincing argument as to why no revision is needed. To facilitate our review, we prefer that the cover letter include the comments made by the reviewers and the editor followed by your response. The revised manuscript should indicate the position of all changes made. We suggest that you use the "track changes" feature in your word processing software to do so (rather than strikethrough or underline formatting). Your paper will be maintained in active status for 21 days from the date of this letter. If we have not heard from you by Jan 10, 2019, we will assume you wish to withdraw the manuscript from further consideration. REVIEWER COMMENTS:Reviewer #1: This is a retrospective study using clinical information to predict success rate after ECV in 250 women at 36-41 week' gestation. All procedures were performed by the same experienced physician. After using creative Condition inference classification tree analysis , they found that parity , BMI , and fore bag size in cm are the best predictors for success. They found that fore bag size, BMI, and parity are the best predictors for ECV success. I have few comments 1. Despite the impressive results , the findings are not generalizable to clinical practice since all procedures were performed by one experienced provider.2. What are the years of the study? the authors should include the time period.3. The authors provide data on mean BMi. Do they have data on number of those with AFI< 5 or deepest vertical pocket < 2 cm.? how do they compare to the fore bag data.? 4. Data relating to parity and BMI are not surprising , and data on fore bag size is a proxy for lack of engagement. 5. The average BMI for the patient population is way different than that in the US. I am interested to see how the Fore bag size will predict ECV in those with BMI > 40.6. The authors should provide more data on obstetric outcomes other than admission to NICU. It is surprising that no complications are included.Reviewer #2: This is a retrospective cohort study designed to develop a prediction model to predict success after external cephalic version for breech presentation at term. The study identified 3 independent predictors including: fore-bag size, BMI and prior vaginal birth.

Preterm birth is considered one of the main etiologies of neonatal death, as well as short- and long-term disability worldwide. A number of pathophysiological processes take place in the final unifying factor of cervical modifications that leads to preterm birth. In women at high risk for preterm birth, cervical assessment is commonly used for prediction and further risk stratification. This review outlines the rationale for cervical length screening for preterm birth prediction in different clinical settings within existing and evolving new technologies to assess cervical remodeling.

Background: Visual and acoustic virtual reality (VR) has been increasingly explored as a non-pharmacological tool for pain relief in clinical settings.Objective: We aimed to evaluate the effectiveness of VR as a distraction technique in the management of acute pain during operative hysteroscopy in the outpatient setting. Methods:A prospective, open-label, randomized control trial in a tertiary university-affiliated medical centre between April and August 2020. Overall, 82 women were randomly allocated to undergo operative hysteroscopy either with the use of VR (n = 44, study group) or with standard treatment (control group, n = 38). VR was applied throughout the procedure and no anaesthesia was given. The primary outcome measures included self-reported intraoperative pain. Other objectives included vital parameters as pulse rate (PR) and respiratory rate (RR) before and during the first 3 min of the procedure. Pain and anxiety outcomes were measured as numeric rating scores. Results:The baseline parameters were similar between groups. The mean duration for the procedure was 8.1 ± 3.2 vs. 7.3 ± 6.0 min for the study and the control groups (p = 0.23). There were no statistically significant differences between the reported pain scores during the procedure [median (interquartile range) 5.0 (3.0-7.2) vs. 5.0 (3.0-8.0), respectively; p = 0.67]. While neither intraoperative heart rate nor respiratory rate differed between groups [14.0 (13.0-16.0) vs. 14.0 (11.0-16.5); p = 0.77)], the increase of heart rate was found greater in the VR group [+7.0 (8.5) vs. +1.0 (12.2); p = 0.01]. Conclusion:VR was not effective in reducing pain during an outpatient operative hysteroscopy.Significance: The use of a Virtual reality system was found ineffective in reducing pain during and after an office operative hysteroscopy without anaesthesia, in a thorough examination of both continuous physiological parameters and women's self-reported measures.This accompanies the following article: Dualé, C & Mourgues, C. The price of pain relief, or should non-invasive medical devices be treated differently in analgesic clinical trials?.