A document by Shi Ting Pang. Click on the document to view its contents.

Background: Multiple gestation has a higher incidence of preterm birth(PTB), especially in the presence of a short cervix. Objectives: To perform a systematic review and network meta-analysis(NMA) evaluating the effect of progesterone, cerclage, cervical pessary and their combination as treatments for preventing PTB<34 weeks. Search strategy: PubMed, MEDLINE, Cochrane Library, EMBASE, Web of Science, BVS, Scopus, and grey literature were explored. Selection criteria: We included randomized controlled trials that compared an intervention with a control group or another intervention to prevent PTB in women with a twin pregnancy and a short cervix<40mm. Data collection and Analysis:Studies were checked for trustworthiness. We presented summary relative effect sizes(Odds Ratios) for each possible pair of interventions and we used the surface under the cumulative ranking curves(SUCRA) to rank all interventions. Main Results: A total of 20 studies participated in NMA. We found no evidence that the combined treatment of pessary and vaginal progesterone reduced the risk of spontaneous PTB <34 weeks when compared to no intervention(OR 0.68; 95%CI 0.16 to 2.9). Also, pessary(OR 0.78; 95%CI 0.49 to 1.3), vaginal progesterone(OR 0.79; CI95% 0.45 to 1.4) and injectable 17-OH progesterone alone(OR 0.85; CI95% 0.26 to 2.8) did not show a statistically significant reduction in spontaneous PTB. For overall PTB<34 weeks, findings were similar. Conclusions: We found no evidence that progesterone, cervical pessary, cerclage or their combination reduce PTB<34 weeks. There is an urgent need for randomized trials assessing these treatments in women with a multiple pregnancy and a short cervix.

Background: Postpartum Haemorrhage (PPH) remains a leading cause of maternal mortality and morbidity worldwide, and the rate is increasing. Using a reliable predictive model could identify those at risk, support management and treatment, and improve maternal outcomes. Objectives: To systematically identify and appraise existing prognostic models for PPH and ascertain suitability for clinical use. Search strategy: MEDLINE, CINAHL, Embase, and the Cochrane Library were searched using combinations of terms and synonyms including ‘postpartum haemorrhage’, ‘prognostic model’, and ‘risk factors’ that were developed from a scoping review. Selection Criteria: Observational or experimental studies describing a prognostic model for risk of PPH, published in English. Data Collection and Analysis: The Critical Appraisal and Data Extraction for Systematic Reviews of Prediction Modelling Studies checklist informed data extraction and Prediction Model Risk of Bias Assessment Tool guided analysis. Main Results: 16 studies met the inclusion criteria after screening 1612 records. All studies were hospital settings from 8 different countries. Models were developed for women who experienced vaginal birth (n=7), caesarean birth(n=2), any type of birth(n=2), hypertensive disorders(n=1) and those with placental abnormalities(n=4). All studies were at high risk of bias due to use of inappropriate analysis methods or omission of important statistical considerations or suboptimal validation. Conclusions: No existing prognostic models for PPH are ready for clinical application. Future research is needed to externally validate existing models and potentially develop a new model that is reliable and applicable to clinical practice. Funding: This study received no funding. Keywords: Postpartum haemorrhage, prognostic model, prediction tool.

Background: As pregnancy is a physiological prothrombotic state, pregnant women may be at increased risk of developing coagulopathic and/or thromboembolic complications associated with COVID-19. Objectives: To investigate the occurrence of haemostatic and thrombo-embolic complications in pregnant women with COVID-19. Search Strategy: Two biomedical databases were searched between September 2019 and June 2020 for case reports and series of pregnant women with COVID-19. Additional registry cases known to the authors were included. Steps were taken to minimise duplicate patients. Selection criteria: Pregnant women with COVID-19 based either on a positive swab or high clinical suspicion e.g. symptoms and radiographic evidence. Data Collection and Analysis: Information on coagulopathy based on abnormal coagulation test results or clinical evidence of disseminated intravascular coagulation (DIC), and on arterial or venous thrombosis, were extracted using a standard form. If available, detailed laboratory results and information on maternal outcomes were analysed. Main Results: 1063 women met the inclusion criteria, of which three (0.28%) had arterial and/or venous thrombosis, seven (0.66%) had DIC, and a further three (0.28%) had coagulopathy without meeting the definition of DIC. Five hundred and thirty-seven women (56%) had been reported as having given birth and 426 (40%) as having an ongoing pregnancy. There were 17 (1.6%) maternal deaths in which DIC was reported as a factor in two. Conclusions: Our data suggests that coagulopathy and thromboembolism are both increased in pregnancies affected by COVID-19. Detection of the former may be useful in the identification of women at risk of deterioration.

Authors’ reply re: ’Maternal transmission of SARS-COV-2 to the neonate, and possible routes for such transmission: A systematic review and critical analysis (Response to BJOG-20-1416)Kate F Walker1, Keelin O’Donoghue2, Nicky Grace3, Jon Dorling4, Jeannette L Comeau4, Wentao Li5 Jim G Thornton11Division of Child Health, Obstetrics and Gynaecology, School of Medicine, University of Nottingham2The Irish Centre for Maternal and Child Health, University College Cork, Cork University Maternity Hospital, Cork, Ireland3 School of English, University of Nottingham4Department of Pediatrics, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada5Department of Obstetrics and Gynaecology, Monash University, Clayton, AustraliaThank you for the opportunity to comment on the letter by Dr Xue from Shanghai Jiao Tong University. We agree there are many weaknesses in the data we reviewed. Dr Xue has identified one. Others are the incomplete reporting of infant feeding and mother-child interactions, and the frequent lack of infant testing to confirm or refute the possibility of vertical transmission of COVID-19. Finally, although we simply provided summary totals, it would be statistically preferable to combine series using the Mantel-Haenszel method and calculate a relative risk. We judged that doing this in light of the uncertainties around the data which Dr Xue has identified, might give a spurious precision to our results. As he says, more work is needed. For now we think it remains reasonable to not regard COVID-19 in itself, as an indication for Caesarean, artificial feeding or separation, in the mother and baby’s interest.