Factors infl uencing delivery in women with multiple fetus pregnancy.

OBJECTIVE: This paper aims to analyze the factors that can influence the method of childbirth in women with multiple pregnancies. MATERIALS AND METHODS: Retrospective analysis of selected parameters in women with multiple pregnancies who gave birth at the 2nd Clinic of Gynecology and Obstetrics of the Faculty of Medicine (FM), Comenius University (CU) and University Hospital (UH) Bratislava in the years 2010-2022. RESULTS: Between 2010 and 2022, at the 2nd Clinic of Gynecology and Obstetrics of the FM CU and UH in Bratislava, 1.13% of births were multiple pregnancies. After statistical data processing, primiparity appeared statistically significant as a risk of acute caesarean section (C-section); multiparous women had a higher probability to give birth vaginally. Since 2017, the clinic has had a decreasing trend in the number of caesarean sections. Women with an acute caesarean section, in turn had on average a lower pH of both fetuses compared to vaginal delivery. However, the incidence of asphyxia in fetuses was not statistically significantly different. We found no risk factor increasing the likelihood of acute caesarean section for fetus B in twins. CONCLUSION: Multiple pregnancy has a higher morbidity not only for the woman but also for the fetuses. The incidence of multiple pregnancies is influenced by assisted reproduction. Delivery method depends on various factors such as chorionicity, fetal presentation, and history of a previous caesarean section.

Optimization of cooling rate of Q-P treated 42SiCr steel using AI digital twinning.

In the continuously advancing field of mechanical engineering, digitalization is bringing a major transformation, specifically with the concept of digital twins. Digital twins are dynamic digital models of real-world systems and processes, crucial for Industry 4.0 and the emerging Industry 5.0, which are changing how humans and machines work together in manufacturing. This paper explores the combination of physics-based and data-driven modeling using advanced Artificial Intelligence (AI) and Machine Learning (ML) techniques. This approach provides a comprehensive understanding of mechanical systems, improving materials design and manufacturing processes. The focus is on the advanced 42SiCr alloy, where AI-driven digital twinning is used to optimize cooling rates during Quenching and Partitioning (Q-P) treatments. This leads to significant improvements in the mechanical properties of 42SiCr steel. Given its complex properties influenced by various factors, this alloy is perfect for digital twinning. The Q-P heat treatment process not only restores the material's deformability but also gives it advanced high-strength steel (AHSS) properties. The findings show how AI and ML can effectively guide the development of high-strength steels and enhance their treatment processes. Additionally, integrating digital twins with new technologies like the Metaverse offers exciting possibilities for simulated production, remote monitoring, and collaborative design. By establishing a clear workflow from physical to digital twins and presenting empirical results, this paper connects theoretical modeling with practical applications, paving the way for smarter manufacturing solutions in mechanical engineering. Furthermore, this paper analyzes how digital twins can be integrated into advanced technologies like the Metaverse, opening up new possibilities for simulated production, remote monitoring, design collaboration, training simulations, analytics, and complete supply chain visibility. This integration is a crucial step toward realizing the full potential of digitalization in mechanical engineering.

Early childhood development strategy for the world's children with disabilities.

Early childhood is foundational for optimal and inclusive lifelong learning, health and well-being. Young children with disabilities face substantial risks of sub-optimal early childhood development (ECD), requiring targeted support to ensure equitable access to lifelong learning opportunities, especially in low- and middle-income countries. Although the Sustainable Development Goals, 2015-2030 (SDGs) emphasise inclusive education for children under 5 years with disabilities, there is no global strategy for achieving this goal since the launch of the SDGs. This paper explores a global ECD framework for children with disabilities based on a review of national ECD programmes from different world regions and relevant global ECD reports published since 2015. Available evidence suggests that any ECD strategy for young children with disabilities should consists of a twin-track approach, strong legislative support, guidelines for early intervention, family involvement, designated coordinating agencies, performance indicators, workforce recruitment and training, as well as explicit funding mechanisms and monitoring systems. This approach reinforces parental rights and liberty to choose appropriate support pathway for their children. We conclude that without a global disability-focussed ECD strategy that incorporates these key features under a dedicated global leadership, the SDGs vision and commitment for the world's children with disabilities are unlikely to be realised.

Inflammatory markers in relation to maternal lifestyle and adverse pregnancy outcomes in twin pregnancies.

It is well known that inflammatory markers play an important role in the development and maintenance of healthy pregnancies. However, the literature regarding inflammation in relation to lifestyle and adverse pregnancy outcomes in twin pregnancies is remarkably uncovered. Therefore, this study aimed at evaluating the concentration of inflammatory markers in dried capillary blood spot samples from 523 women with twin pregnancies, included at a median gestational age of 21+1 weeks. The relationship between inflammatory markers and maternal lifestyle (current smoking status and pre-pregnancy body mass index) in addition to adverse pregnancy outcomes (preeclampsia, gestational diabetes mellitus, and small for gestational age) was analyzed. The study showed that active smoking at inclusion was associated with an elevated concentration of interleukin-8. Furthermore, maternal obesity was associated with an elevated concentration of C-reactive protein and monocyte chemoattractant protein-1. Analysis of the data showed no statistically significant variations in the concentration of the assessed inflammatory markers for neither preeclampsia, gestational diabetes mellitus, nor small for gestational age. The current study promotes future research on the pathophysiology of twin pregnancies in relation to adverse pregnancy outcomes, as the literature within the area remains scarce.

Quantitative and calculated estimated blood loss in cesarean deliveries for twin and singleton pregnancies: a retrospective analysis.

PURPOSE: This study retrospectively assessed blood loss during cesarean deliveries for twin and singleton pregnancies using two distinct methods, quantitative estimation measured during cesarean sections and hematocrit-based calculated estimation. METHODS: We included scheduled cesarean deliveries for twin or singleton pregnancies at ≥ 34 weeks of gestation. Quantitative blood loss was recorded based on the blood volume in the graduated collector bottle and by weighing the blood-soaked textiles during cesarean sections. The blood loss was calculated using the change in hematocrit levels before and after the cesarean delivery. RESULTS: We evaluated 403 cases including 44 twins and 359 singletons. Quantitative blood loss during cesarean section was significantly higher in twin pregnancies than that in singleton pregnancies (1117 [440] vs 698 [378] mL; p < 0.001). However, no significant differences were observed in the calculated blood loss between the two groups on the day after delivery (487 mL [692 mL] vs 507 mL [522 mL]; p = 0.861). On post-delivery days 4-5, twin pregnancies were associated with a significantly higher calculated blood loss than singleton pregnancies (725 [868] mL vs 444 [565] mL, p = 0.041). Although a significant moderate correlation between quantitative and calculated blood loss was observed in singleton pregnancies (r = 0.473, p < 0.001), no significant correlation was observed between twin pregnancies (r = 0.053, p = 0.735). CONCLUSION: Quantitative blood loss measurements during cesarean section may be clinically insufficient in twin pregnancies. Incorporating blood tests and continuous assessments are warranted for enhanced blood loss evaluation, especially in twin pregnancies, owing to the risk of persistent bleeding.

First copy number variant in trans with single nucleotide variant in CCN6 causing progressive pseudorheumatoid dysplasia revealed by genome sequencing and deep phenotyping in monozygotic twins.

Biallelic pathogenic variants in CCN6 cause progressive pseudorheumatoid dysplasia (PPD), a rare skeletal dysplasia. The predominant features include noninflammatory progressive joint stiffness and enlargement, which are not unique to this condition. Nearly 100% of the reported variants are single nucleotide variants or small indels, and missing of a second variant has been reported. Genome sequencing (GS) covers various types of variants and deep phenotyping (DP) provides detailed and precise information facilitating genetic data interpretation. The combination of GS and DP improves diagnostic yield, especially in rare and undiagnosed diseases. We identified a novel compound heterozygote involving a disease-causing copy number variant (g.112057664_112064205del) in trans with a single nucleotide variant (c.624dup(p.Cys209MetfsTer21)) in CCN6 in a pair of monozygotic twins, through the methods of GS and DP. The twins had received three nondiagnostic results before. The g.112057664_112064205del variant was missed by all the tests, and the recorded phenotypes were inaccurate or even misleading. The twins were diagnosed with PPD, ending a 13-year diagnostic odyssey. There may be other patients with PPD experiencing underdiagnosis and misdiagnosis due to inadequate genetic testing or phenotyping methods. This case highlights the critical role of GS and DP in facilitating an accurate and timely diagnosis.

Genetics and sleep bruxism: a systematic review and meta-analysis of studies with twins.

OBJECTIVE: To systematically review the literature regarding the concordance of sleep bruxism (SB) between monozygotic (MZ) and dizygotic (DZ) twins. METHODS: The registration for this systematic review was accomplished in the International Prospective Register of Systematic Reviews (PROSPERO, No. CRD42021251751). As of July 2022, four databases were searched, including PubMed, Scopus, Embase, and Web of Science, as well as the grey literature in Google Scholar and OpenGrey. Observational studies evaluating SB in MZ and DZ twins of any age and sex were included. For the evaluation of the risk of bias, the Joanna Briggs checklist was utilized. The certainty of evidence was assessed via the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. Pooled and subgroup meta-analyses were performed to estimate concordance of SB ​​between twins (p < 0.05). RESULTS: In total, 3,155 records were identified. In the qualitative analysis, eleven studies were included; of these, seven were included in the meta-analysis. The majority of the articles exhibited a low risk of bias (63.6%). Greater SB concordance was observed between MZ twins than between DZ twins in the analysis of general concordance (OR = 1.47; 95% CI = 1.07-2.02) and also positive concordance (OR = 1.53; 95% CI = 1.29-1.81). Within the subgroup analyses, the significance of the findings remained only for the reported/self-reported SB regarding general concordance (OR = 1.44; 95% CI = 1.07-1.95) and positive concordance (OR = 1.55; 95% CI = 1.28-1.88). Low certainty of the evidence was observed for the general concordance analysis, while moderate certainty was observed for the positive concordance. CONCLUSION: There was a higher concordance of SB in MZ twins compared to DZ twins, indicating a possible genetic influence on the condition's occurrence.

Computational modeling of heart failure in microgravity transitions.

The space tourism industry is growing due to advances in rocket technology. Privatised space travel exposes non-professional astronauts with health profiles comprising underlying conditions to microgravity. Prior research has typically focused on the effects of microgravity on human physiology in healthy astronauts, and little is known how the effects of microgravity may play out in the pathophysiology of underlying medical conditions, such as heart failure. This study used an established, controlled lumped mathematical model of the cardiopulmonary system to simulate the effects of entry into microgravity in the setting of heart failure with both, reduced and preserved ejection fraction. We find that exposure to microgravity eventuates an increased cardiac output, and in patients with heart failure there is an unwanted increase in left atrial pressure, indicating an elevated risk for development of pulmonary oedema. This model gives insight into the risks of space flight for people with heart failure, and the impact this may have on mission success in space tourism.

The effect of perceived social support on fatigue in mothers having twin infants: the mediating role of sleep quality.

The aim of this study is to investigate the mediating role of sleep quality in the relationship between multidimensional perceived social support and fatigue among mothers of twin infants. One hundred and six (106) twin mothers participated in this cross-sectional study, who completed the Descriptive Information Form, Multidimensional Scale of Perceived Social Support, Pittsburgh Sleep Quality Index, and Checklist Individual Strength. The scale score averages of the mothers in the study are as follows: social support, 61.41 ± 23.86; fatigue, 77.64 ± 28.68; and sleep quality, 8.26 ± 2.38. According to the path model, perceived social support has a negative effect on poor sleep quality (p = .001, Beta = -0.411), and poor sleep quality has a positive effect on fatigue (p = .001, Beta = 0.335). Sleep quality also mediates the effect of multidimensional perceived social support on mothers' fatigue levels (p = .001, Beta = -0.138). The study results suggest that the perceived social support and fatigue levels of twin mothers are moderate, while their sleep quality is poor. Therefore, mothers of twin infants may benefit from increased social support to alleviate fatigue and enhance sleep quality.

The influence of previous preterm birth with singleton pregnancy on the risk of recurrence in subsequent twin pregnancy: a meta-analysis.

BACKGROUND: Preterm birth is a significant obstetrical concern around the globe. With this study, we aimed to determine whether a prior singleton pregnancy preterm birth increases the likelihood of preterm birth in subsequent twin pregnancies. We designed his systematic review to provide valuable information for pregnant women and obstetricians during counselling and for individuals involved in the planning of preventive strategies. METHODS: We comprehensively searched the PubMed, Embase and Scopus databases to identify relevant studies published until October 2023 following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We applied a random-effects meta-analysis to the data gathered from the selected studies. RESULTS: Among the 460 initially identified studies, only eight met the eligibility criteria. The analysis of incidence revealed an event rate of 9.5% (95% CI, 4.4-19.5%) for a history of preterm singleton birth in the cohort of women with subsequent twin pregnancies. Subgroup analyses focused on the risk of preterm twin births (<37 weeks, <34 weeks and <32 weeks) in women with prior preterm singleton births. Our results revealed a significantly elevated risk of subsequent preterm twin births associated with prior preterm singleton births at <37 weeks (OR, 2.94; 95% CI, 1.99-4.33; p < .001), <34 weeks (OR, 1.89; 95% CI, 1.67-2.14; p < .001) and <32 weeks (OR, 2.51; 95% CI, 1.58-3.99; p < .001), without heterogeneity in the included studies. CONCLUSIONS: Our systematic analysis indicates a consistent and statistically significant association between a history of preterm singleton births and preterm twin births at various gestational ages. These findings underscore the importance of the obstetric history during assessments to predict the risk of preterm births in twin pregnancies. Clinicians should monitor pregnancies with a history of preterm singleton births, as targeted interventions and improved prenatal care can mitigate the risk of preterm birth during twin pregnancies.

Preterm birth, a global concern, prompted a study examining whether a prior preterm singleton birth raises the risk of preterm birth in subsequent twin pregnancies. Conducting a systematic review of 460 studies, only eight met the eligibility criteria. The meta-analysis revealed a 9.5% incidence of preterm singleton births in subsequent twin pregnancies. Further analysis demonstrated a significantly elevated risk of preterm twin births at <32 weeks for those with a history of preterm singleton births. The study concludes that a consistent and statistically significant association exists between prior preterm singleton births and increased preterm twin birth risk at various gestational ages. This underscores the importance of considering obstetric history in assessing preterm birth risk in twin pregnancies. Clinicians are advised to closely monitor pregnancies with a history of preterm singleton births for interventions targeted and improved prenatal care.

Genetic and environmental determinants of bone quality: a cross-sectional analysis of the Hungarian Twin Registry.

There is abundant evidence that bone mineral content is highly heritable, while the heritability of bone quality (i.e. trabecular bone score [TBS] and quantitative ultrasound index [QUI]) is rarely investigated. We aimed to disentangle the role of genetic, shared and unique environmental factors on TBS and QUI among Hungarian twins. Our study includes 82 twin (48 monozygotic, 33 same-sex dizygotic) pairs from the Hungarian Twin Registry. TBS was determined by DXA, QUI by calcaneal bone ultrasound. To estimate the genetic and environmental effects, we utilized ACE-variance decomposition. For the unadjusted model of TBS, an AE model provided the best fit with > 80% additive genetic heritability. Adjustment for age, sex, BMI and smoking status improved model fit with 48.0% of total variance explained by independent variables. Furthermore, there was a strong dominant genetic effect (73.7%). In contrast, unadjusted and adjusted models for QUI showed an AE structure. Adjustments improved model fit and 25.7% of the total variance was explained by independent variables. Altogether 70-90% of the variance in QUI was related to additive genetic influences. We found a strong genetic heritability of bone quality in unadjusted models. Half of the variance of TBS was explained by age, sex and BMI. Furthermore, the adjusted model suggested that the genetic component of TBS could be dominant or an epistasis could be present. In contrast, independent variables explained only a quarter of the variance of QUI and the additive heritability explained more than half of all the variance.

Cushing's disease with twin pregnancy and diabetes mellitus: a case report and literature review.

A 38-year-old Japanese woman with a history of abnormal thyroid function of non-autoimmune origin, pituitary endocrine tumor, and untreated diabetes mellitus was referred to our outpatient clinic when she became pregnant with twins. Physical findings consistent with Cushing's syndrome (CS) were absent at the time of presentation. Although baseline plasma adrenocorticotropic hormone, serum cortisol, and 24-hour urinary free cortisol excretion levels were above the upper limits of normal non-pregnant reference ranges, we could not exclude a physiological increase associated with pregnancy. No medical or surgical intervention for hypercortisolism was performed during pregnancy. Spontaneous vaginal delivery resulted in the normal delivery of live twins. A diagnosis of Cushing's disease (CD) was established when papery skin developed postpartum. Transsphenoidal surgery was performed and the hypercortisolism partially resolved post-operatively. The patient's abnormal thyroid function also resolved. Pregnancy in women with endogenous CS is rare, with less than 300 cases reported. Most reported cases of CS during pregnancy are of adrenal origin. Only two cases of twin pregnancies with CD have been reported. Therefore, we reported the third case of CD in a twin pregnancy and reviewed the diagnostic and therapeutic challenges associated with CD during pregnancy.

Five years of change in adult twins: longitudinal changes of genetic and environmental influence on epigenetic clocks.

BACKGROUND: Epigenetic clocks were known as promising biomarkers of aging, including original clocks trained by individual CpG sites and principal component (PC) clocks trained by PCs of CpG sites. The effects of genetic and environmental factors on epigenetic clocks are still unclear, especially for PC clocks. METHODS: We constructed univariate twin models in 477 same-sex twin pairs from the Chinese National Twin Registry (CNTR) to estimate the heritability of five epigenetic clocks (GrimAge, PhenoAge, DunedinPACE, PCGrimAge, and PCPhenoAge). Besides, we investigated the longitudinal changes of genetic and environmental influences on epigenetic clocks across 5 years in 134 same-sex twin pairs. RESULTS: Heritability of epigenetic clocks ranged from 0.45 to 0.70, and those for PC clocks were higher than those for original clocks. For five epigenetic clocks, the longitudinal stability was moderate to high and was largely due to genetic effects. The genetic correlations between baseline and follow-up epigenetic clocks were moderate to high. Special unique environmental factors emerged both at baseline and at follow-up. PC clocks showed higher longitudinal stability and unique environmental correlations than original clocks. CONCLUSIONS: For five epigenetic clocks, they have the potential to identify aging interventions. High longitudinal stability is mainly due to genetic factors, and changes of epigenetic clocks over time are primarily due to changes in unique environmental factors. Given the disparities in genetic and environmental factors as well as longitudinal stability between PC and original clocks, the results of studies with original clocks need to be further verified with PC clocks.

From transcriptomics to digital twins of organ function.

Cell level functions underlie tissue and organ physiology. Gene expression patterns offer extensive views of the pathways and processes within and between cells. Single cell transcriptomics provides detailed information on gene expression within cells, cell types, subtypes and their relative proportions in organs. Functional pathways can be scalably connected to physiological functions at the cell and organ levels. Integrating experimentally obtained gene expression patterns with prior knowledge of pathway interactions enables identification of networks underlying whole cell functions such as growth, contractility, and secretion. These pathways can be computationally modeled using differential equations to simulate cell and organ physiological dynamics regulated by gene expression changes. Such computational systems can be thought of as parts of digital twins of organs. Digital twins, at the core, need computational models that represent in detail and simulate how dynamics of pathways and networks give rise to whole cell level physiological functions. Integration of transcriptomic responses and numerical simulations could simulate and predict whole cell functional outputs from transcriptomic data. We developed a computational pipeline that integrates gene expression timelines and systems of coupled differential equations to generate cell-type selective dynamical models. We tested our integrative algorithm on the eicosanoid biosynthesis network in macrophages. Converting transcriptomic changes to a dynamical model allowed us to predict dynamics of prostaglandin and thromboxane synthesis and secretion by macrophages that matched published lipidomics data obtained in the same experiments. Integration of cell-level system biology simulations with genomic and clinical data using a knowledge graph framework will allow us to create explicit predictive models that mechanistically link genomic determinants to organ function. Such integration requires a multi-domain ontological framework to connect genomic determinants to gene expression and cell pathways and functions to organ level phenotypes in healthy and diseased states. These integrated scalable models of tissues and organs as accurate digital twins predict health and disease states for precision medicine.

Effectiveness and pregnancy outcomes of ultrasound-indicated and physical examination-indicated cervical cerclage: a retrospective study from a single centre.

OBJECTIVE: Preterm birth (PTB) is the leading cause of neonatal morbidity and mortality worldwide, and cervical incompetence (CIC) is a significant contribution. Cervical cerclage (CC) is an effective obstetric intervention. However, many clinical factors affect the success rate of surgery. The objective was to investigate and compare the pregnancy and neonatal outcomes of patients who underwent ultrasound- and physical examination-indicated cervical cerclage and to explore the influencing factors of preterm delivery before 34 weeks. METHODS: The sociodemographic characteristics and clinical data of patients with a diagnosis of cervical incompetence who underwent ultrasound- and physical examination-indicated transvaginal cervical cerclage at Nanjing Maternal and Child Health Hospital from January 2020 to December 2022 were retrospectively analyzed. The pregnancy and neonatal outcomes of the patients were evaluated. Continuous variables were compared using Student's t test (for normally distributed data) or the Mann-Whitney U test (for nonnormally distributed data). Categorical variables were analysed using the chi-square test or Fisher's exact test. Additionally, logistic regression analyses and receiver operating characteristic curves were used to evaluate the associations of inflammatory markers with maternal and neonatal outcomes. RESULTS: This study included 141 participants who underwent cervical cerclage, including 71 with ultrasound-indicated cerclage and 70 with physical examination-indicated cerclage. Compared to those in the ultrasound-indicated cerclage group, the duration from cerclage to delivery, birth weight, and APGAR score in the physical examination-indicated cerclage group were significantly lower, and the rates of delivery at < 28 weeks, < 32 weeks, < 34 weeks, and < 37 weeks of gestation and neonatal mortality were significantly higher (all P < 0.05). Compared to those in the physical ultrasound-indicated cerclage group, in the physical examination-indicated cerclage group, maternal blood inflammatory markers, such as C-reactive protein (CRP), the systemic immune-inflammation index (SII) and the systemic inflammation response index (SIRI) were significantly higher (P < 0.05). Additionally, maternal blood inflammatory markers, such as the CRP, white blood cell count, platelet to lymphocyte ratio (PLR), SII, and SIRI were significantly higher in the group with delivery before 34 weeks of gestation. Furthermore, the results demonstrated that twin pregnancy had the highest OR for preterm delivery before 34 weeks of gestation (OR = 3.829; 95% CI 1.413-10.373; P = 0.008), as well as the following: the SII level (OR = 1.001; 95% CI 1.000-1.002; P = 0.003) and CRP level (OR = 1.083; 95% CI 1.038-1.131; P = 0.022). The risk factors for preterm delivery before 34 weeks of gestation were twin gestation, an increased SII level and an increased CRP level, which had good combined predictive value. CONCLUSION: In patients with cervical insufficiency, ultrasound-indicated cervical cerclage appears to lead to better pregnancy outcomes than physical examination-indicated cerclage. Twin pregnancy and maternal blood inflammatory markers, such as the CRP level and the SII, are associated with preterm delivery before 34 weeks of gestation.

Pregnancy outcomes of foetal reduction from twin to singleton gestation compared to ongoing twin gestations: a systematic review and meta-analysis.

BACKGROUND: Foetal reduction, which involves selectively terminating one or more foetuses in a multiple gestation pregnancy, has become more common. This systematic review and meta-analysis aims to assess and compare pregnancy outcomes of foetal reduction from twin to singleton gestation to ongoing twin gestations. METHODS: A comprehensive search of electronic databases (MEDLINE, EMbase, Cochrane Library, CINAHL and PsycINFO) was done for studies published until 15 April 2023. The outcomes analysed included gestational diabetes mellitus (DM), hypertension, caesarean delivery, foetal loss, perinatal death, preterm birth (PTB), intrauterine growth restriction (IUGR), preterm prelabour rupture of membranes (PPROM) and birth weight. RESULTS: A total of 13 studies comprising 1241 cases of twin to singleton foetal reduction gestation were compared to 20,693 ongoing twin gestations. Our findings indicate that foetal reduction was associated with a significantly lower risk of developing maternal gestational DM (odds ratio [OR] = 0.40, 95% confidence interval [CI] 0.27-0.59) and hypertension (OR = 0.36, 95% CI 0.23-0.57) compared to the control group. Incidence rate of caesarean delivery (OR = 0.65, 95% CI 0.53-0.81) after foetal reduction was significantly lower compared to ongoing twin gestations. There was a 63% lower chance of PTB before 37 weeks of pregnancy. However, there was no significant association between foetal reduction and outcomes such as foetal loss, perinatal death, IUGR and PPROM. CONCLUSIONS: Our findings suggest that foetal twin to singleton reduction entails potential benefits as compared to ongoing twin gestations. Further well planned studies are needed to explore underlying mechanisms to understanding of the outcomes associated with foetal reduction procedures and inform clinical decision-making for pregnant individuals and healthcare providers alike.

Foetal reduction, a procedure where one or more foetuses in a twin pregnancy are selectively terminated, has become more common. This study reviewed existing research to compare the outcomes of foetal reduction to singleton pregnancies with those of ongoing twin pregnancies. The study found that mothers who underwent foetal reduction had a lower risk of developing gestational diabetes and hypertension, and they were less likely to have a caesarean delivery. There was also a reduced chance of preterm birth before 37 weeks. However, foetal reduction did not appear to significantly impact outcomes like foetal loss, perinatal death, intrauterine growth restriction or preterm pre-labour rupture of membranes. It is important to note that there is some variation in the results among different studies, and more research is needed to fully understand these findings.

Development and validation of a technical skill score for internal version and total breech extraction of the second twin: An interventional prospective study.

OBJECTIVE: To develop and test an Objective Structured Assessment of Technical Skills (OSATS) score for the internal version and total breech extraction of the second twin if in a non-engaged cephalic position. MATERIALS AND METHODS: This prospective interventional study took place in a tertiary obstetrics department in France. An objective scoring system was developed, and a standardized simulation scenario was set up. Score evaluation was blinded and analyzed according to group and number of past successful vaginal twin deliveries in real life. A satisfaction evaluation was performed, based on the "Student Design Scale" questionnaire. RESULTS: Simulation was performed on 33 participants in three groups: novice group (15 first- and second-year residents), intermediate group (11 third- to sixth-year residents), and expert group (seven senior obstetricians). The total score obtained by experts was higher than that of the intermediate group (P = 0.001), which was higher than that of the novice group (P < 0.001). In the intermediate group, no correlation was found between OSATS score and number of past successful vaginal twin deliveries. Participants' satisfaction was excellent. CONCLUSION: The OSATS score developed was reliable and valid to evaluate an internal version and a total breech extraction of the second twin, and to differentiate novice, intermediate, and expert practitioners.

Intertwin discordance of aldosterone levels in amniotic fluid with placental anastomoses in monochorionic twins: Insight into the pathophysiology of twin-to-twin transfusion syndrome.

INTRODUCTION: Our objective was to investigate the association between the presence of placental anastomoses and intertwin differences in renin-angiotensin-aldosterone activation in monochorionic twins using amniotic fluid aldosterone (AF-ALD) levels. In addition, this study also examined the association between AF-ALD and the ALD levels in the umbilical cord blood (UCB-ALD) in monochorionic twins. MATERIAL AND METHODS: This prospective study included monochorionic diamniotic (MD) twin pregnancies that were not complicated by twin-to-twin transfusion syndrome (TTTS) at delivery. Amniotic fluid and umbilical cord vein blood samples were collected from each twin at delivery, and the ALD levels were measured subsequently. The MD twins were divided into two groups: those with placental anastomoses and those without anastomoses owing to fetoscopic laser surgery. The differences in the AF-ALD levels between the larger and smaller twins were analyzed. RESULTS: The AF-ALD levels showed a strong and significant positive correlation with UCB-ALD levels in 131 MD twins (r = 0.804, p < 0.001). Intertwin differences were examined in 41 and 28 pairs of MD twins with and without placental anastomoses, respectively. The AF-ALD levels in the smaller twins were significantly higher than those in the larger twins among the pairs of MD twins with placental anastomoses (p = 0.003); however, no statistically significant intertwin differences were observed among the twins without placental anastomoses (p > 0.05). CONCLUSIONS: The AF-ALD levels reflect the UCB-ALD levels in MD twins. The presence of placental anastomoses led to intertwin discordance in the ALD levels in MD twins even uncomplicated with TTTS. It was considered that monochorionic twins have this clinical background, and it leads to the development of TTTS.

Is Feto-Maternal Transfusion after Cesarean Delivery Different in Singleton and Twin Pregnancy?

Background: The aim of the study was to investigate if feto-maternal transfusion was related to the size of the fetal-maternal interface, and, therefore, was larger in twin pregnancy in comparison with singleton pregnancy. Methods: Blood samples from women with singleton (n = 11), and monochorionic (n = 11) and dichorionic (n = 13) twin gestations were tested. Flow cytometry tests with hemoglobin F, glycophorin A, and hemoglobin F and carbonic anhydrase simultaneous staining were used to detect fetal red blood cells and maternal F cells. Results: In all cases, the volume of feto-maternal transfusion was estimated to be low. The highest rate of fetal red blood cells in the maternal circulation was observed in the blood of women with dichorionic twin gestations both before and after delivery. An increase in fetal red blood cells was observed after cesarean section in singletons and twins. The median rate of maternal F cells was 2.23% in singleton, 2.1% in monochorionic and 3.95% in dichorionic pregnancy. Conclusions: Feto-maternal transfusion during pregnancy may be related to the multiplicity and chorionicity of pregnancy.

Twin-Tool Orientation Synchronous Smoothing Algorithm of Pinch Milling in Nine-Axis Machine Tools.

Pinch milling is a new technique for slender and long blade machining, which can simultaneously improve the machining quality and efficiency. However, two-cutter orientation planning is a major challenge due to the irregular blade surfaces and the structural constraints of nine-axis machine tools. In this paper, a method of twin-tool smoothing orientation determination is proposed for a thin-walled blade with pinch milling. Considering the processing status of the two cutters and workpiece, the feasible domain of the twin-tool axis vector and its characterization method are defined. At the same time, an evaluation algorithm of global and local optimization is proposed, and a smoothing algorithm is explored within the feasible domain along the two tool paths. Finally, a set of smoothly aligned tool orientations are generated, and the overall smoothness is nearly globally optimized. A preliminary simulation verification of the proposed algorithm is conducted on a turbine blade model and the planning tool orientation is found to be stable, smooth, and well formed, which avoids collision interference and ultimately improves the machining accuracy of the blade with difficult-to-machine materials.