Search

Placenta accreta spectrum (PAS) is a condition often resulting in severe maternal morbidity. Scheduled delivery by an experienced team has been shown to improve maternal outcomes; however, the benefits must be weighed against the risk of iatrogenic prematurity. The aim of this study is to investigate the rates of emergency delivery seen for antenatally suspected PAS and compare the resulting outcomes in the 15 referral centers of the International Society for PAS (IS-PAS). Fifteen centers provided cases between 2008 and 2019. The women included were divided into two groups according to whether they had a planned or an emergency cesarean delivery. Delivery was defined as "planned" when performed at a time and date to suit the team. All the remaining cases were classified as "emergency". Maternal characteristics and neonatal outcomes were compared between the two groups according to gestation at delivery. In all, 356 women were included. Of these, 239 (67%) underwent a planned delivery and 117 (33%) an emergency delivery. Vaginal bleeding was the indication for emergency delivery in 41 of the 117 women (41%). There were no significant differences in terms of blood loss, transfusion rates or major maternal morbidity between planned and emergency deliveries. However, the rate of maternal intensive therapy unit admission was increased with emergency delivery (45% vs 33%, P = .02). Antepartum hemorrhage was the only independent predictor of emergency delivery (aOR: 4.3, 95% confidence interval 2.4-7.7). Emergency delivery due to vaginal bleeding was more frequent with false-positive cases (antenatally suspected but not confirmed as PAS at delivery) and the milder grades of PAS (accreta/increta). The rate of infants experiencing any major neonatal morbidity was 25% at 34 to 36 weeks and 19% at >36 weeks. Emergency delivery in centers of excellence did not increase blood loss, transfusion rates or maternal morbidity. The single greatest risk factor for emergency delivery

Introduction: Placenta accreta spectrum (PAS) is a condition often resulting in severe maternal morbidity. Scheduled delivery by an experienced team has been shown to improve maternal outcomes; however, the benefits must be weighed against the risk of iatrogenic prematurity. The aim of this study is to investigate the rates of emergency delivery seen for antenatally suspected PAS and compare the resulting outcomes in the 15 referral centers of the International Society for PAS (IS-PAS). Material and methods: Fifteen centers provided cases between 2008 and 2019. The women included were divided into two groups according to whether they had a planned or an emergency cesarean delivery. Delivery was defined as “planned” when performed at a time and date to suit the team. All the remaining cases were classified as “emergency”. Maternal characteristics and neonatal outcomes were compared between the two groups according to gestation at delivery. Results: In all, 356 women were included. Of these, 239 (67%) underwent a planned delivery and 117 (33%) an emergency delivery. Vaginal bleeding was the indication for emergency delivery in 41 of the 117 women (41%). There were no significant differences in terms of blood loss, transfusion rates or major maternal morbidity between planned and emergency deliveries. However, the rate of maternal intensive therapy unit admission was increased with emergency delivery (45% vs 33%, P =.02). Antepartum hemorrhage was the only independent predictor of emergency delivery (aOR: 4.3, 95% confidence interval 2.4-7.7). Emergency delivery due to vaginal bleeding was more frequent with false-positive cases (antenatally suspected but not confirmed as PAS at delivery) and the milder grades of PAS (accreta/increta). The rate of infants experiencing any major neonatal morbidity was 25% at 34+1 to 36+0 weeks and 19% at >36+0 weeks. Conclusions: Emergency delivery in centers of excellence did not increase blood lo

Introduction: Placenta accreta spectrum (PAS) carries a high burden of adverse maternal outcomes, especially significant blood loss, which can be life-threatening. Different management strategies have been proposed but the association of clinical risk factors and surgical management options during cesarean delivery with high blood loss is not clear. Material and methods: In this international multicenter study, 338 women with PAS undergoing cesarean delivery were included. Fourteen European and one non-European center (USA) provided cases treated retrospectively between 2008 and 2014 and prospectively from 2014 to 2019. Peripartum blood loss was estimated visually and/or by weighing and measuring of volume. Participants were grouped based on blood loss above or below the 75th percentile (>3500 ml) and the 90th percentile (>5500 ml). Results: Placenta percreta was found in 58% of cases. Median blood loss was 2000 ml (range: 150-20 000 ml). Unplanned hysterectomy was associated with an increased risk of blood loss >3500 ml when compared with planned hysterectomy (adjusted OR [aOR] 3.7 [1.5-9.4], p = 0.01). Focal resection was associated with blood loss comparable to that of planned hysterectomy (crude OR 0.7 [0.2–2.1], p = 0.49). Blood loss >3500 ml was less common in patients undergoing successful conservative management (placenta left in situ, aOR 0.1 [0.0–0.6], p = 0.02) but was more common in patients who required delayed hysterectomy (aOR 6.5 [1.7–24.4], p = 0.001). Arterial occlusion methods (uterine or iliac artery ligation, embolization or intravascular balloons), application of uterotonic medication or tranexamic acid showed no significant effect on blood loss >3500 ml. Patients delivered by surgeons without experience in PAS were more likely to experience blood loss >3500 ml (aOR 3.0 [1.4–6.4], p = 0.01). Conclusions: In pregnant women with PAS, the likelihood of blood loss >3500 ml was reduced in planned vs unplanned cesarean deliver

In this dissertation we treat several problems from mathematical physics via methods from functional analysis and probability theory and in particular operator semigroups. The thesis consists thematically of two parts. In the first part we consider so-called generalized stochastic Hamiltonian systems. These are generalizations of Langevin dynamics which describe interacting particles moving in a surrounding medium. From a mathematical point of view these systems are stochastic differential equations with a degenerated diffusion coefficient. We construct weak solutions of these equations via the corresponding martingale problem. Therefore, we prove essential m-dissipativity of the degenerated and non-sectorial It\^{o} differential operator. Further, we apply results from the analytic and probabilistic potential theory to obtain an associated Markov process. Afterwards we show our main result, the convergence in law of the positions of the particles in the overdamped regime, the so-called overdamped limit, to a distorted Brownian motion. To this end, we show convergence of the associated operator semigroups in the framework of Kuwae-Shioya. Further, we established a tightness result for the approximations which proves together with the convergence of the semigroups weak convergence of the laws. In the second part we deal with problems from infinite dimensional Analysis. Three different issues are considered. The first one is an improvement of a characterization theorem of the so-called regular test functions and distribution of White noise analysis. As an application we analyze a stochastic transport equation in terms of regularity of its solution in the space of regular distributions. The last two problems are from the field of relativistic quantum field theory. In the first one the $ (\Phi)_3^4 $-model of quantum field theory is under consideration. We show that the Schwinger functions of this model have a representation as the moments of a positive Hida distributio

In this dissertation we treat several problems from mathematical physics via methods from functional analysis and probability theory and in particular operator semigroups. The thesis consists thematically of two parts. In the first part we consider so-called generalized stochastic Hamiltonian systems. These are generalizations of Langevin dynamics which describe interacting particles moving in a surrounding medium. From a mathematical point of view these systems are stochastic differential equations with a degenerated diffusion coefficient. We construct weak solutions of these equations via the corresponding martingale problem. Therefore, we prove essential m-dissipativity of the degenerated and non-sectorial It\^{o} differential operator. Further, we apply results from the analytic and probabilistic potential theory to obtain an associated Markov process. Afterwards we show our main result, the convergence in law of the positions of the particles in the overdamped regime, the so-called overdamped limit, to a distorted Brownian motion. To this end, we show convergence of the associated operator semigroups in the framework of Kuwae-Shioya. Further, we established a tightness result for the approximations which proves together with the convergence of the semigroups weak convergence of the laws. In the second part we deal with problems from infinite dimensional Analysis. Three different issues are considered. The first one is an improvement of a characterization theorem of the so-called regular test functions and distribution of White noise analysis. As an application we analyze a stochastic transport equation in terms of regularity of its solution in the space of regular distributions. The last two problems are from the field of relativistic quantum field theory. In the first one the $ (\Phi)_3^4 $-model of quantum field theory is under consideration. We show that the Schwinger functions of this model have a representation as the moments of a positive Hida distributio

In this dissertation we treat several problems from mathematical physics via methods from functional analysis and probability theory and in particular operator semigroups. The thesis consists thematically of two parts. In the first part we consider so-called generalized stochastic Hamiltonian systems. These are generalizations of Langevin dynamics which describe interacting particles moving in a surrounding medium. From a mathematical point of view these systems are stochastic differential equations with a degenerated diffusion coefficient. We construct weak solutions of these equations via the corresponding martingale problem. Therefore, we prove essential m-dissipativity of the degenerated and non-sectorial It\^{o} differential operator. Further, we apply results from the analytic and probabilistic potential theory to obtain an associated Markov process. Afterwards we show our main result, the convergence in law of the positions of the particles in the overdamped regime, the so-called overdamped limit, to a distorted Brownian motion. To this end, we show convergence of the associated operator semigroups in the framework of Kuwae-Shioya. Further, we established a tightness result for the approximations which proves together with the convergence of the semigroups weak convergence of the laws. In the second part we deal with problems from infinite dimensional Analysis. Three different issues are considered. The first one is an improvement of a characterization theorem of the so-called regular test functions and distribution of White noise analysis. As an application we analyze a stochastic transport equation in terms of regularity of its solution in the space of regular distributions. The last two problems are from the field of relativistic quantum field theory. In the first one the $ (\Phi)_3^4 $-model of quantum field theory is under consideration. We show that the Schwinger functions of this model have a representation as the moments of a positive Hida distributio