Classifications for Cesarean Section: A Systematic Review

Background: Rising cesarean section (CS) rates are a major public health concern and cause worldwide debates. To propose and implement effective measures to reduce or increase CS rates where necessary requires an appropriate classification. Despite several existing CS classifications, there has not yet been a systematic review of these. This study aimed to 1) identify the main CS classifications used worldwide, 2) analyze advantages and deficiencies of each system.Methods and Findings: Three electronic databases were searched for classifications published 1968-2008. Two reviewers independently assessed classifications using a form created based on items rated as important by international experts. Seven domains (ease, clarity, mutually exclusive categories, totally inclusive classification, prospective identification of categories, reproducibility, implementability) were assessed and graded. Classifications were tested in 12 hypothetical clinical case-scenarios. From a total of 2948 citations, 60 were selected for full-text evaluation and 27 classifications identified. Indications classifications present important limitations and their overall score ranged from 2-9 (maximum grade = 14). Degree of urgency classifications also had several drawbacks (overall scores 6-9). Woman-based classifications performed best (scores 5-14). Other types of classifications require data not routinely collected and may not be relevant in all settings (scores 3-8).Conclusions: This review and critical appraisal of CS classifications is a methodologically sound contribution to establish the basis for the appropriate monitoring and rational use of CS. Results suggest that women-based classifications in general, and Robson's classification, in particular, would be in the best position to fulfill current international and local needs and that efforts to develop an internationally applicable CS classification would be most appropriately placed in building upon this classification. the use of a single CS classification will facilitate auditing, analyzing and comparing CS rates across different settings and help to create and implement effective strategies specifically targeted to optimize CS rates where necessary.Universidade Federal de São Paulo, Dept Obstet, São Paulo, BrazilBrazilian Cochrane Ctr, São Paulo, BrazilWorld Hlth Org, Dept Reprod Hlth & Res, Geneva, SwitzerlandWorld Hlth Org, Dept Knowledge Management & Sharing, Geneva, SwitzerlandUniversidade Federal de São Paulo, Dept Obstet, São Paulo, BrazilWeb of Scienc

Diet and physical activity in pregnancy to prevent gestational diabetes:A protocol for an individual participant data (IPD) meta-analysis on the differential effects of interventions with economic evaluation

Introduction: Mothers with gestational diabetes mellitus (GDM) are at increased risk of pregnancy-related complications and developing type 2 diabetes after delivery. Diet and physical activity-based interventions may prevent GDM, but variations in populations, interventions and outcomes in primary trials have limited the translation of available evidence into practice. We plan to undertake an individual participant data (IPD) meta-analysis of randomised trials to assess the differential effects and cost-effectiveness of diet and physical activity-based interventions in preventing GDM and its complications. Methods: The International Weight Management in Pregnancy Collaborative Network database is a living repository of IPD from randomised trials on diet and physical activity in pregnancy identified through a systematic literature search. We shall update our existing search on MEDLINE, Embase, BIOSIS, LILACS, Pascal, Science Citation Index, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Database of Abstracts of Reviews of Effects and Health Technology Assessment Database without language restriction to identify relevant trials until March 2021. Primary researchers will be invited to join the Network and share their IPD. Trials including women with GDM at baseline will be excluded. We shall perform a one and two stage random-effect meta-analysis for each intervention type (all interventions, diet-based, physical activity-based and mixed approach) to obtain summary intervention effects on GDM with 95% CIs and summary treatment–covariate interactions. Heterogeneity will be summarised using I2 and tau2 statistics with 95% prediction intervals. Publication and availability bias will be assessed by examining small study effects. Study quality of included trials will be assessed by the Cochrane Risk of Bias tool, and the Grading of Recommendations, Assessment, Development and Evaluations approach will be used to grade the evidence in the results. A model-based economic analysis will be carried out to assess the cost-effectiveness of interventions to prevent GDM and its complications compared with usual care. Ethics and dissemination: Ethics approval is not required. The study is registered on the International Prospective Register of Systematic Reviews (CRD42020212884). Results will be submitted for publication in peer-reviewed journals

Large introns in relation to alternative splicing and gene evolution: a case study of Drosophila bruno-3

Background: Alternative splicing (AS) of maturing mRNA can generate structurally and functionally distinct transcripts from the same gene. Recent bioinformatic analyses of available genome databases inferred a positive correlation between intron length and AS. To study the interplay between intron length and AS empirically and in more detail, we analyzed the diversity of alternatively spliced transcripts (ASTs) in the Drosophila RNA-binding Bruno-3 (Bru-3) gene. This gene was known to encode thirteen exons separated by introns of diverse sizes, ranging from 71 to 41,973 nucleotides in D. melanogaster. Although Bru-3's structure is expected to be conducive to AS, only two ASTs of this gene were previously described. Results: Cloning of RT-PCR products of the entire ORF from four species representing three diverged Drosophila lineages provided an evolutionary perspective, high sensitivity, and long-range contiguity of splice choices currently unattainable by high-throughput methods. Consequently, we identified three new exons, a new exon fragment and thirty-three previously unknown ASTs of Bru-3. All exon-skipping events in the gene were mapped to the exons surrounded by introns of at least 800 nucleotides, whereas exons split by introns of less than 250 nucleotides were always spliced contiguously in mRNA. Cases of exon loss and creation during Bru-3 evolution in Drosophila were also localized within large introns. Notably, we identified a true de novo exon gain: exon 8 was created along the lineage of the obscura group from intronic sequence between cryptic splice sites conserved among all Drosophila species surveyed. Exon 8 was included in mature mRNA by the species representing all the major branches of the obscura group. To our knowledge, the origin of exon 8 is the first documented case of exonization of intronic sequence outside vertebrates. Conclusion: We found that large introns can promote AS via exon-skipping and exon turnover during evolution likely due to frequent errors in their removal from maturing mRNA. Large introns could be a reservoir of genetic diversity, because they have a greater number of mutable sites than short introns. Taken together, gene structure can constrain and/or promote gene evolution

Deficiency of X-Linked Inverted Duplicates with Male-Biased Expression and the Underlying Evolutionary Mechanisms in the Drosophila Genome

Inverted duplicates (IDs) are pervasive in genomes and have been reported to play functional roles in various biological processes. However, the general underlying evolutionary forces that maintain IDs in genomes remain largely elusive. Through a systematic screening of the Drosophila melanogaster genome, 20,223 IDs were detected in nonrepetitive intergenic regions, far more than expectation under the neutrality model. 3,846 of these IDs were identified to have stable hairpin structure (i.e., the structural IDs). Based on whole-genome transcriptome profiling data, we found 628 unannotated expressed structural IDs, which had significantly different genomic distributions and structural properties from the unexpressed IDs. Among the expressed structural IDs, 130 exhibited higher expression in males than in females (i.e., male-biased expression). Compared with sex-unbiased ones, these male-biased IDs were significantly underrepresented on the X chromosome, similar to previously reported pattern of male-biased protein-coding genes. These analyses suggest that a selection-driven process, rather than a purely neutral mutation-driven mechanism, contributes to the maintenance of IDs in the Drosophila genome

Late pregnancy vitamin D deficiency is associated with doubled odds of birth asphyxia and emergency caesarean section: A prospective cohort study

Objectives: The aim of this prospective cohort study was to investigate the associations between maternal vitamin D status in late pregnancy and emergency caesarean section (EMCS) and birth asphyxia, in a population based sample of women in Sweden. Methods: Pregnant women were recruited at the antenatal care in Sweden and 1832 women were included after exclusion of miscarriages, terminated pregnancies and missing data on vitamin D status. Mode of delivery was retrieved from medical records. EMCS was defined as caesarean section after onset of labour. Birth asphyxia was defined as either 5 min Apgar score < 7 or arterial umbilical cord pH < 7.1. Serum was sampled in the third trimester of pregnancy (T3) and 25-hydroxyvitamin D (25OHD) was analysed by liquid chromatography tandem mass spectrometry. Vitamin D deficiency was defined as 25OHD < 30 nmol/L, and associations were studied using logistic regression analysis and expressed as adjusted odds ratios (AOR). Results: In total, 141 (7.7%) women had an EMCS and 58 (3.2%) children were born with birth asphyxia. Vitamin D deficiency was only associated with higher odds of EMCS in women without epidural anaesthesia (AOR = 2.01, p = 0.044). Vitamin D deficiency was also associated with higher odds of birth asphyxia (AOR = 2.22, p = 0.044). Conclusions for Practice: In this Swedish prospective population-based cohort study, vitamin D deficiency in late pregnancy was associated with doubled odds of birth asphyxia and with EMCS in deliveries not aided by epidural anaesthesia. Prevention of vitamin D deficiency among pregnant women may reduce the incidence of EMCS and birth asphyxia. The mechanism behind the findings require further investigation

Cell salvage and donor blood transfusion during cesarean section: A pragmatic, multicentre randomised controlled trial (SALVO)

BACKGROUND: Excessive haemorrhage at cesarean section requires donor (allogeneic) blood transfusion. Cell salvage may reduce this requirement. METHODS AND FINDINGS: We conducted a pragmatic randomised controlled trial (at 26 obstetric units; participants recruited from 4 June 2013 to 17 April 2016) of routine cell salvage use (intervention) versus current standard of care without routine salvage use (control) in cesarean section among women at risk of haemorrhage. Randomisation was stratified, using random permuted blocks of variable sizes. In an intention-to-treat analysis, we used multivariable models, adjusting for stratification variables and prognostic factors identified a priori, to compare rates of donor blood transfusion (primary outcome) and fetomaternal haemorrhage ≥2 ml in RhD-negative women with RhD-positive babies (a secondary outcome) between groups. Among 3,028 women randomised (2,990 analysed), 95.6% of 1,498 assigned to intervention had cell salvage deployed (50.8% had salvaged blood returned; mean 259.9 ml) versus 3.9% of 1,492 assigned to control. Donor blood transfusion rate was 3.5% in the control group versus 2.5% in the intervention group (adjusted odds ratio [OR] 0.65, 95% confidence interval [CI] 0.42 to 1.01, p = 0.056; adjusted risk difference -1.03, 95% CI -2.13 to 0.06). In a planned subgroup analysis, the transfusion rate was 4.6% in women assigned to control versus 3.0% in the intervention group among emergency cesareans (adjusted OR 0.58, 95% CI 0.34 to 0.99), whereas it was 2.2% versus 1.8% among elective cesareans (adjusted OR 0.83, 95% CI 0.38 to 1.83) (interaction p = 0.46). No case of amniotic fluid embolism was observed. The rate of fetomaternal haemorrhage was higher with the intervention (10.5% in the control group versus 25.6% in the intervention group, adjusted OR 5.63, 95% CI 1.43 to 22.14, p = 0.013). We are unable to comment on long-term antibody sensitisation effects. CONCLUSIONS: The overall reduction observed in donor blood transfusion associated with the routine use of cell salvage during cesarean section was not statistically significant. TRIAL REGISTRATION: This trial was prospectively registered on ISRCTN as trial number 66118656 and can be viewed on http://www.isrctn.com/ISRCTN66118656

Одноколейные тракторно-ледяные дороги: учебное пособие для лесотехнических вузов

Книга содержит описание конструкций однополозных тракторных саней, расчет основных деталей саней, краткие технические условия проектирования одноколейных тракторно-ледяных дорог, правила постройки и эксплуатации ледяных дорог и основы организации тракторного хозяйства на базе одноколейных ледяных дорог. Книга предназначена в качестве учебного пособия для лесотехнических вузов, но может также служить практическим пособием и для высшего технического персонала лесозаготовительных предприятий Наркомлеса СССР.0|7|Предисловие [c. 7]0|8|Введение [c. 8]0|11|Возникновение и развитие конструкции однополозных саней [c. 11]1|11|Первые опыты [c. 11]1|12|Принцип работы одноколейной ледяной дороги и теоретические основания проектирования однополозных саней [c. 12]1|17|Конструкция первых однополозных саней [c. 17]1|17|Однополозные сани Востокостальлеса [c. 17]1|19|Одкополозные сани ЦНИИМЭ, модель Б [c. 19]1|21|Однополозные сани на базе поковок тракторных двухполозных саней модели Д [c. 21]1|22|Однополозные сани Я. И. Гинзбурга модели 1939 г. [c. 22]1|33|Однополозные сани ГЗЯ-2 [c. 33]1|39|Варианты соединения коника с полозом [c. 39]1|39|Модернизированные однополозные сани на базе поковок саней модели Свердлеса и Востокостальлеса [c. 39]1|44|Бескониковые однополозные сани конструкции СибНИИЛХЭ [c. 44]1|46|Буферно-прицепные устройства трактора конструкции УЛТИ, Сотринского мехлесопункта и Стройлеспроекта [c. 46]1|48|Автоматическая сцепка тракторных саней [c. 48]1|49|Рама для перевозки коротья на однополозных санях [c. 49]1|51|Расчет саней [c. 51]1|51|Расчет полоза [c. 51]1|58|О форме подрезов [c. 58]0|61|Постройка одноколейных ледяных дорог [c. 61]1|61|Условия применения, сырьевая база и порядок оформления строительства [c. 61]1|62|Технические условия проектирования одноколейных ледяных дорог [c. 62]1|72|Изыскания трасс одноколейных ледяных дорог [c. 72]1|73|Строительные работы на одноколейных ледяных дорогах [c. 73]1|85|Дорожные орудия для строительства одноколейных ледяных дорог [c. 85]1|91|Цистерны для поливки ледяной дороги [c. 91]1|91|Насосные станции [c. 91]0|95|Эксплуатация ледяных дорог [c. 95]1|95|Техническая характеристика тяговых машин [c. 95]1|107|Эксплуатация газогенераторных тракторов на лесовывозке по ледяным дорогам [c. 107]1|115|Правила вождения поездов [c. 115]1|117|Формирование состава и маневры [c. 117]1|117|Содержание и ремонт пути ледяной дороги [c. 117]1|119|Техника безопасности при вывозке леса по тракторным ледяным дорогам [c. 119]1|121|Основные правила по технике безопасности для тракторного лесотранспорта [c. 121]0|123|Приложения [c. 123]1|123|Детали однополозных саней ГЗЯ-1 [c. 123]1|136|Детали модернизированных однополозных саней на базе поковок саней Свердллеса [c. 136]1|141|Краткая техническая характеристика гусеничных тракторов Челябинского тракторного завода [c. 141]0|143|Оглавление [c. 143

Progression of the first stage of spontaneous labour: A prospective cohort study in two sub-Saharan African countries.

BACKGROUND: Escalation in the global rates of labour interventions, particularly cesarean section and oxytocin augmentation, has renewed interest in a better understanding of natural labour progression. Methodological advancements in statistical and computational techniques addressing the limitations of pioneer studies have led to novel findings and triggered a re-evaluation of current labour practices. As part of the World Health Organization's Better Outcomes in Labour Difficulty (BOLD) project, which aimed to develop a new labour monitoring-to-action tool, we examined the patterns of labour progression as depicted by cervical dilatation over time in a cohort of women in Nigeria and Uganda who gave birth vaginally following a spontaneous labour onset. METHODS AND FINDINGS: This was a prospective, multicentre, cohort study of 5,606 women with singleton, vertex, term gestation who presented at ≤ 6 cm of cervical dilatation following a spontaneous labour onset that resulted in a vaginal birth with no adverse birth outcomes in 13 hospitals across Nigeria and Uganda. We independently applied survival analysis and multistate Markov models to estimate the duration of labour centimetre by centimetre until 10 cm and the cumulative duration of labour from the cervical dilatation at admission through 10 cm. Multistate Markov and nonlinear mixed models were separately used to construct average labour curves. All analyses were conducted according to three parity groups: parity = 0 (n = 2,166), parity = 1 (n = 1,488), and parity = 2+ (n = 1,952). We performed sensitivity analyses to assess the impact of oxytocin augmentation on labour progression by re-examining the progression patterns after excluding women with augmented labours. Labour was augmented with oxytocin in 40% of nulliparous and 28% of multiparous women. The median time to advance by 1 cm exceeded 1 hour until 5 cm was reached in both nulliparous and multiparous women. Based on a 95th percentile threshold, nulliparous women may take up to 7 hours to progress from 4 to 5 cm and over 3 hours to progress from 5 to 6 cm. Median cumulative duration of labour indicates that nulliparous women admitted at 4 cm, 5 cm, and 6 cm reached 10 cm within an expected time frame if the dilatation rate was ≥ 1 cm/hour, but their corresponding 95th percentiles show that labour could last up to 14, 11, and 9 hours, respectively. Substantial differences exist between actual plots of labour progression of individual women and the 'average labour curves' derived from study population-level data. Exclusion of women with augmented labours from the study population resulted in slightly faster labour progression patterns. CONCLUSIONS: Cervical dilatation during labour in the slowest-yet-normal women can progress more slowly than the widely accepted benchmark of 1 cm/hour, irrespective of parity. Interventions to expedite labour to conform to a cervical dilatation threshold of 1 cm/hour may be inappropriate, especially when applied before 5 cm in nulliparous and multiparous women. Averaged labour curves may not truly reflect the variability associated with labour progression, and their use for decision-making in labour management should be de-emphasized

A Single Nucleotide Polymorphism within the Novel Sex-Linked Testis-Specific Retrotransposed PGAM4 Gene Influences Human Male Fertility

The development of novel fertilization treatments, including in vitro fertilization and intracytoplasmic injection, has made pregnancy possible regardless of the level of activity of the spermatozoa; however, the etiology of male-factor infertility is poorly understood. Multiple studies, primarily through the use of transgenic animals, have contributed to a list of candidate genes that may affect male infertility in humans. We examined single nucleotide polymorphisms (SNPs) as a cause of male infertility in an analysis of spermatogenesis-specific genes.We carried out the prevalence of SNPs in the coding region of phosphoglycerate mutase 4 (PGAM4) on the X chromosome by the direct sequencing of PCR-amplified DNA from male patients. Using RT-PCR and western blot analyses, we identified that PGAM4 is a functional retrogene that is expressed predominantly in the testes and is associated with male infertility. PGAM4 is expressed in post-meiotic stages, including spermatids and spermatozoa in the testes, and the principal piece of the flagellum and acrosome in ejaculated spermatozoa. A case-control study revealed that 4.5% of infertile patients carry the G75C polymorphism, which causes an amino acid substitution in the encoded protein. Furthermore, an assay for enzymatic activity demonstrated that this polymorphism decreases the enzyme's activity both in vitro and in vivo.These results suggest that PGAM4, an X-linked retrogene, is a fundamental gene in human male reproduction and may escape meiotic sex chromosome inactivation. These findings provide fresh insight into elucidating the mechanisms of male infertility