Conoscopic interferometry of wafers for surface-acoustic wave devices

We show that in interpreting the conoscopic interference fringes, one should exercise care in employing approximate expressions which fail for certain crystal cuts. In this paper, we study 64°- and 128°-rotated Y-cut and Z-cut LiNbO3 wafers. We show that the error made in using the approximate formulae for the samples is more than 25% and that one has to use exact formulae in order to attain quantitative agreement with the experimental data.Peer reviewe

Anaphylaxis in pregnancy : a population-based multinational European study

Anaphylaxis in pregnancy is a rare but severe complication for both mother and infant. Population-based data on anaphylaxis in pregnancy are lacking from mainland European countries. This multinational study presents the incidence, causative agents, management and maternal and infant outcomes of anaphylaxis in pregnancy. This descriptive multinational study used a combination of retrospective (Finnish medical registries) and prospective population-based studies (UK, France, Belgium and the Netherlands) to identify cases of anaphylaxis. Sixty-five cases were identified among 4,446,120 maternities (1.5 per 100,000 maternities; 95%CI 1.1-1.9). The incidence did not vary between countries. Approximately three-quarters of reactions occurred at the time of delivery. The most common causes were antibiotics in 27 women (43%), and anaesthetic agents in 11 women (17%; including neuromuscular blocking drugs, 7), which varied between countries. Anaphylaxis had very poor outcomes for one in seven mothers and one in seven babies; the maternal case fatality rate was 3.2% (95%CI 0.4-11.0) and the neonatal encephalopathy rate was 14.3% (95%CI 4.8-30.3). Across Europe, anaphylaxis related to pregnancy is rare despite having a multitude of causative agents and different antibiotic prophylaxis protocols.Peer reviewe

Anaphylaxis in pregnancy : a population-based multinational European study

Funding Information: M‐P B, OA, and GV had equal contributions to this study. We thank T. Schapp, J. Zwart and E. Overtoom in the NethOSS team; C. Daoui from the French SFAR Research Network; the B.OSS team and Belgian maternity units involved in this study. The work was funded by the Medical Research Council (MRC) and the Nuffield Department of Population Health. The views expressed in this publication are those of the authors and not necessarily those of the MRC. The funders had no role in the study design, data collection and analysis, decision to publish or preparation of the article. Permission for the use and sharing of registry and medical records was obtained from the National Institute for Health and Welfare (THL), Finland. Approval was acquired from the B.OSS and NethOSS steering committee for the data collection and sharing of anonymous data for this anaphylaxis study. The French Data Protection Authority approved the collection of the data (CNIL 1985389). All the women in France were informed of anonymised data collection during the study. B.oSS gained approval for data collection from the Ghent University Ethics Committee as central EC (2015/1470, amendment 23/06/2016, B670201526875), and gained informed consent of all women included in the study. The Central University Research Ethics Committee, University of Oxford gave approval to complete this prospective observational study (Reference R46400/RE001). Data sharing statement: Data cannot be shared publicly due to confidentiality issues arising from small numbers of cases in mainland European countries. Requests for access to the UK dataset will be considered by the National Perinatal Epidemiology Unit Data Sharing committee. Access to the data can be requested from [email protected] . No other external funding or competing interests declared. Publisher Copyright: © 2020 The Authors. Anaesthesia published by John Wiley & Sons Ltd on behalf of Association of Anaesthetists Copyright: Copyright 2020 Elsevier B.V., All rights reserved.Peer reviewedPublisher PD

COVID-19 in pregnancy—characteristics and outcomes of pregnant women admitted to hospital because of SARS-CoV-2 infection in the Nordic countries

cited By 0Introduction Population-based studies about the consequences of SARS-CoV-2 infection (COVID-19) in pregnancy are few and have limited generalizability to the Nordic population and healthcare systems. Material and methods This study examines pregnant women with COVID-19 in the five Nordic countries. Pregnant women were included if they were admitted to hospital between 1 March and 30 June 2020 and had a positive SARS-CoV-2 PCR test Results In the study areas, 214 pregnant women with a positive test were admitted to hospital, of which 56 women required hospital care due to COVID-19. The risk of admission due to COVID-19 was 0.4/1000 deliveries in Denmark, Finland and Norway, and 3.8/1000 deliveries in the Swedish regions. Women hospitalized because of COVID-19 were more frequently obese (p < 0.001) and had a migrant background (p < 0.001) compared with the total population of women who delivered in 2018. Twelve women (21.4%) needed intensive care. Among the 56 women admitted due to COVID-19, 48 women delivered 51 infants. Preterm delivery (n = 12, 25%, p < 0.001) and cesarean delivery (n = 21, 43.8%, p < 0.001) were more frequent in women with COVID-19 compared with women who delivered in 2018. No maternal deaths, stillbirths or neonatal deaths were reported. Conclusions The risk of admission due to COVID-19 disease in pregnancy was low in the Nordic countries. A fifth of the women required intensive care and we observed higher rates of preterm and cesarean deliveries. National public health policies appear to have had an impact on the risk of admission due to severe COVID-19 disease in pregnancy. Nordic collaboration is important in collecting robust data and assessing rare outcomes.Peer reviewe

Variations across Europe in hospitalization and management of pregnant women with SARS-CoV-2 during the initial phase of the pandemic : Multi-national population-based cohort study using the International Network of Obstetric Survey Systems (INOSS)

Funding Information: The national studies reported the following funding sources: The BOSS project was funded by the Belgian Federal Public Service of Health. The NOSS collaboration was supported by the Nordic Federation of Societies of Obstetrics and Gynecology (grant no. 6505, 2020). NOSS‐Denmark was supported by grants from The Region of Southern Denmark and Region Zealand's shared fund for joint health research projects (Reg. no. A767), and EasyTrial provided the data collection software. NOSS‐Finland received grants from the Finnish Medical Society, and from Helsinki University. UKOSS received funding from the National Institute for Health Research HS&DR Programme (11/46/12). The national studies in Italy and the Netherlands did not have specific funding. The multi‐national study received partial funding support from the European Medicines Agency (EMA) under the Framework service contract nr EMA/2018/28/PE. The content of this paper expresses the opinions of the authors and may not be understood or quoted as being made on behalf of or reflecting the position of the EMA or any of its committees or working parties. The research leading to these results was conducted as part of the activities of the EU PE&PV (Pharmacoepidemiology and Pharmacovigilance) Research Network, which is a public academic partnership coordinated by Utrecht University, the Netherlands. The CONSIGN project was scientifically coordinated by the University Medical Center, Utrecht. Funding Information: OB declares support from the European Medicines agency (EMA). HE declares grants from the Nordic Federation of Societies of Obstetrics and Gynecology (NFOG) and Norwegian Research Council (grant no 320181). AA declares a grant from the Region of Southern Denmark and Region Zealand's shared fund for joint health research projects. OA declares grants from the Finnish Medical Association and NFOG. MK declares grants from the National Institute for Health and Care Research, Medical Research Council, Healthcare Quality Improvement Partnership and Wellbeing of Women during the course of the study. MS leads a department that conducts studies on COVID‐19 vaccines for the European Medicines Agency, Pfizer, AstraZeneca and Janssen. All support was according to the ENCePP code of conduct. None of the other authors (NV, RR, SD, EJ, EO, MAS, TS, RV, AV, KB) has anything to disclose. Publisher Copyright: © 2023 The Authors. Acta Obstetricia et Gynecologica Scandinavica published by John Wiley & Sons Ltd on behalf of Nordic Federation of Societies of Obstetrics and Gynecology (NFOG).Introduction: The majority of data on COVID-19 in pregnancy are not from sound population-based active surveillance systems. Material and methods: We conducted a multi-national study of population-based national or regional prospective cohorts using standardized definitions within the International Network of Obstetric Survey systems (INOSS). From a source population of women giving birth between March 1 and August 31, 2020, we included pregnant women admitted to hospital with a positive SARS-CoV-2 PCR test ≤7 days prior to or during admission and up to 2 days after birth. The admissions were further categorized as COVID-19-related or non-COVID-19-related. The primary outcome of interest was incidence of COVID-19-related hospital admission. Secondary outcomes included severe maternal disease (ICU admission and mechanical ventilation) and COVID-19-directed medical treatment. Results: In a source population of 816 628 maternities, a total of 2338 pregnant women were admitted with SARS-CoV-2; among them 940 (40%) were COVID-19-related admissions. The pooled incidence estimate for COVID-19-related admission was 0.59 (95% confidence interval 0.27–1.02) per 1000 maternities, with notable heterogeneity across countries (I2 = 97.3%, P = 0.00). In the COVID-19 admission group, between 8% and 17% of the women were admitted to intensive care, and 5%–13% needed mechanical ventilation. Thromboprophylaxis was the most frequent treatment given during COVID-19-related admission (range 14%–55%). Among 908 infants born to women in the COVID-19-related admission group, 5 (0.6%) stillbirths were reported. Conclusions: During the initial months of the pandemic, we found substantial variations in incidence of COVID-19-related admissions in nine European countries. Few pregnant women received COVID-19-directed medical treatment. Several barriers to rapid surveillance were identified. Investment in robust surveillance should be prioritized to prepare for future pandemics.Peer reviewe

Lessons learnt from anonymized review of cases of peripartum hysterectomy by international experts: A qualitative pilot study

Severe obstetric complications are not extensively studied and individual cases are used too little and inappropriately in quality improvement activities, due to limited numbers and prioritization of quantitative research. Nordic and European experts performed a qualitative pilot study using anonymized cases of peripartum hysterectomy. It was feasible to anonymize narratives and we learned lessons in the form of themes for improved clinical care and future research. Therefore, we plan a Nordic anonymized review of the care of women who have undergone peripartum hysterectomy based on narratives. The qualitative outcomes of clinically relevant themes for quality improvement and research will add value to the quantitative analyses from the Nordic medical birth registries. In the longer term, we believe that qualitative audits should be essential part of the process of continuing improvement in maternity care. This article is protected by copyright. All rights reserved