Three-dimensional (3D) printing, also known as additive manufacturing, is a fabrication technology that constructs three-dimensional objects by successive addition of materials. In recent years, the advancements in 3D printing technology, reductions in material costs, development of biomaterials, and improvements in cell culture techniques allow the application of 3D printing in the clinical medical fields, such as orthopedics, dentistry, and urinary surgery, to develop rapidly. Obstetrics, focusing on both theory and practice, is an emerging application field for 3D printing technology. 3D printing has been used in obstetrics for fetal and maternal diseases, such as prenatal diagnosis of fetal abnormalities and preoperative planning for placental implantation disorders. Additionally, 3D printing can simulate surgical scenarios and enable the targeted training for doctors. This review aims to provide a summary of the latest developments in the clinical application of 3D printing in obstetrics.

Placenta accreta spectrum is a prevalent cause of severe postpartum hemorrhage and emergency hysterectomy.In recent years,there has been an increasing incidence of placenta accreta spectrum.Besides trau-matic uterine injury factors such as elevated cesarean section rates,other non-traumatic factors including uterine malformation,endometritis,uterine adenomyosis,in vitro fertilization-embryo transfer also warrant serious consid-eration.This article focuses on early disease detection,standardized diagnosis,prevention,and treatment of placental implantation disorders associated with non-traumatic factors to enhance the adverse outcomes for these parturients.

Humans ; Infant, Newborn ; Neonatal Screening ; China

Objective:To investigate the effects of placenta previa on the surgical and pregnancy outcomes in patients with total/subtotal or segmental hysterectomy attributed to placenta accreta spectrum disorders (PAS).Methods:This study retrospectively enrolled 510 patients who gave birth and underwent total/subtotal hysterectomy or segmental hysterectomy (local implantation site) due to PAS at the third Affiliated Hospital of Guangzhou Medical University from January 1, 2017, to December 31, 2022. These subjects were divided into the placenta previa group (427 cases) and non-placenta previa group (83 cases). According to the type of hysterectomy, they were further divided into the total/subtotal hysterectomy and placenta previa subgroup (221 cases), total/subtotal hysterectomy and non-placenta previa subgroup (23 cases), segmental hysterectomy and placenta previa subgroup (206 cases), and segmental hysterectomy and non-placenta previa subgroup (60 cases). Nonparametric test or Chi-square test were used to compare the differences in the clinical features, surgical and pregnancy outcomes between different groups. Binary logistic regression was used to analyze the effects of placenta previa on the risk of additional surgical procedures and adverse maternal outcomes. Results:(1) Compared with the non-placenta previa group, the hemorrhage volume within 24 h postpartum [1 541 ml (1 036-2 368 ml) vs 1 111 ml (695-2 000 ml), Z=－3.91] and the proportion of women requiring additional surgical procedures [84.8% (362/427) vs 69.9% (58/83), χ2=10.61], with total/subtotal hysterectomy [51.8% (221/427) vs 27.7% (23/83), χ2=16.10], cystoscopy and/or ureteral stenting [60.7% (259/427) vs 31.3% (26/83), χ2=24.25], total adverse pregnancy outcomes [86.9% (371/427) vs 65.1% (54/83), χ2=17.75], hemorrhage volume>1 500 ml within 24 h postpartum [54.1% (231/427) vs 33.7% (28/83), χ2=29.94], transfusion of blood products [75.9% (324/427) vs 47.0% (39/83), χ2=28.27] were all higher in the placenta previa group (all P<0.05). Binary logistic regression analysis found that for PAS patients with hysterectomy, regardless of the hysterectomy type (total/subtotal/segmental), placenta previa was risk factor for requiring additional surgical procedures ( aOR=3.26, 95% CI: 1.85-5.72) and adverse pregnancy outcomes ( aOR=5.59, 95% CI: 2.01-6.42), even if adjusting for the confounding factors such as maternal age, number of previous cesarean sections, parity, gestational weight gain, twin pregnancy, and the use of assisted reproductive technology. (2) In patients with total/subtotal hysterectomy, the proportion of women requiring additional surgical procedures was higher in those with placenta previa [82.8% (183/221) vs 56.5% (13/23), χ2=9.11] than those without placenta previa, especially the proportion of cystoscopy and/or ureteral stenting [67.9% (150/221) vs 34.8% (8/23), χ2=9.99] (both P<0.05). However, no significant difference was found in adverse pregnancy outcomes [89.6% (198/221) vs 87.0% (20/23), χ2<0.01, P=0.972] between the two groups. In patients with segmental hysterectomy, higher proportions of women requiring additional surgery [86.9% (179/206) vs 75.0% (45/60), χ2=4.94], with adverse pregnancy outcomes [84.0% (173/206) vs 56.7% (34/60), χ2=25.31], cystoscopy and/or ureteral stenting [52.9% (109/206) vs 30.0% (18/60), χ2=9.78], vascular occlusion [94.2% (194/206) vs 71.7% (43/60), χ2=24.23], hemorrhage volume>1 500 ml within 24 h postpartum [46.6% (96/206) vs 23.3% (14/60), χ2=10.37], and transfusion of blood products [68.9% (142/206) vs 33.3% (20/60), χ2=24.73] were found in the placenta previa group (all P<0.05). Furthermore, patients with placenta previa had more hemorrhage volume within 24 h postpartum [1 368 ml (970-2 026 ml) vs 995 ml (654-1 352 ml), Z=－3.66, P<0.001] in the segmental hysterectomy subgroup. After adjusting for the confounding factors such as age, number of previous cesarean sections, parity, gestational weight gain, twin pregnancy, and the use of assisted reproductive technology, binary logistic regression analysis found that placenta previa did not increase the risk of additional surgical operations ( aOR=2.71, 95% CI: 0.99-7.42) and adverse pregnancy outcomes ( aOR=2.14, 95% CI: 0.54-8.42) in patients with total/subtotal hysterectomy but were risk factors of the two outcomes for those with segmental hysterectomy ( aOR=4.67, 95% CI: 2.15-10.10; aOR=3.80, 95% CI: 1.86-7.77). Conclusions:Placenta previa increases the risk of additional surgical procedures and adverse pregnancy outcomes in patients with total/subtotal or segmental hysterectomy caused by PAS. Appropriate preparation is required after the clinical diagnosis of PAS with placenta previa.

Objective:To investigate the safety of the Triple-P procedure in women complicated with severe placenta accreta spectrum disorders (PAS) and its influence on second pregnancy.Methods:From January 2015 to December 2017, the outcomes of the second pregnancy after the Triple-P procedure in 11 pregnant women complicated with PAS in the Third Affiliated Hospital of Guangzhou Medical University and the First Affiliated Hospital of Zhengzhou University were retrospectively analyzed.Results:By December 2021, a total of 11 pregnant women who underwent the Triple-P procedure for PAS had a second pregnancy, with a median interval of 3 years (2-3 years). Of the 11 pregnant women, 7 delivered after 36 weeks of gestation. The median gestational age was 38 weeks, and 4 terminated within the first trimester. PAS recurred in 1 of 7 pregnant women (1/7) and was associated with placenta previa. All of the 7 pregnant women were delivered by cesarean section, with a median postpartum blood loss of 300 ml (200-450 ml), and only one pregnant woman required blood transfusion. None of the pregnant women were transferred to the intensive care unit, and there were no uterine rupture, bladder injury, puerperal infection, and neonatal adverse outcomes.Conclusion:Pregnant women who underwent the Triple-P procedure for severe PAS could be considered for second pregnancy with strictly management by an experienced multidisciplinary team, which may result in a good outcome.

Objective To explore the technology frontiers for neuroblastoma treatment from the perspective of patent citation network. Methods Through patent analysis for neuroblastoma treatment, highly cited patents and highly cited papers in the citation network were taken as the research objects. The title and abstract of the citing patents were analyzed by text clustering to identify the technology frontiers. Through social network analysis, the core patents were identified from the indices of degree centrality, betweenness centrality, closeness centrality, and eigenvector centrality. Results A total of 6240 patent applications for neuroblastoma treatment were found, including 71304 patent citations and 88698 journal-article citations. Four technology frontiers were identified based on patent citation network, namely, drug target, drug design, tumor-indication expansion, and gene-expression regulation. Three technology frontiers were identified based on journal-article citation network. They were drug target, drug design, and tumor-indication expansion. Conclusion The development of technology for neuroblastoma treatment continues to be active. Drug target and drug design are the most important technology frontiers. This study could provide certain reference for neuroblastoma treatment from the perspective of information science.

Objective:To investigate whether the number of previous cesarean sections affects the outcomes of patients with placental implantation disease undergoing hysterectomy.Methods:Using a retrospective cohort study design, the study samples were from the obstetric clinical database of the Third Affiliated Hospital of Guangzhou Medical University, and the study subjects were patients with placental implantation disease who underwent hysterectomy. Patients were grouped according to different previous cesarean section frequencies, and their clinical characteristics, surgical outcomes, and adverse maternal outcomes were compared in each group; The impact of previous cesarean sections on adverse outcomes in pregnant women was analyzed using multivariate logistic regression.Results:Among the 244 enrolled patients, 26 had no previous history of cesarean section (11%), 132 had a previous cesarean section once (54%), and 86 had a previous cesarean section ≥2 times (35%). There was no statistically significant difference in the usage rates of uterine artery embolization, suture hemostasis, and internal iliac artery embolization among the three groups of patients (all P>0.05). Among the adverse outcomes of pregnant and postpartum women, there was no statistically significant difference in the rates of shock, bladder injury, postpartum hemorrhage, postpartum hemorrhage >1 500 ml, admission to the intensive care unit (ICU), and transfusion of blood products among the three groups (all P>0.05). Univariate logistic regression analysis showed that the number of previous cesarean sections did not increase the risk of adverse outcomes, such as shock, postpartum hemorrhage, postpartum hemorrhage ≥1 500 ml, entry into the ICU, and transfusion of blood products. Multivariate logistic regression analysis found that the number of previous cesarean sections did not increase the risk of adverse outcomes in pregnant women. Conclusions:For patients with placental implantation disease undergoing hysterectomy, the number of previous cesarean sections may not be the main factor determining maternal outcomes. It is necessary to consider other possible influencing factors more comprehensively, including previous uterine surgery history, basic health status of pregnant women, comorbidities, and availability of medical resources.

Objectives:To establish a candidate reference measurement procedure based on isotope dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) for cyclosporin A, tacrolimus, sirolimus, and everolimus measurements in human whole blood.Methods:The isotope labeled cyclosporine A, tacrolimus, sirolimus, and everolimus were selected as the internal standards. Samples were accurately weighed while protein precipitation and solid phase extraction were selected for the sample preparation. The standard curve method was applied for quantification. The ultra-high liquid chromatography coupled with triple quadrupole mass spectrometer was used for analysis. The specificity, matrix effect, detection limit, quantification limit, precision, accuracy, and uncertainty of the method were evaluated.Results:The method showed good selectivity and specificity. No apparent interferences or matrix effects were found in the target analyte measurements. The detection limits and quantification limits of cyclosporin A, tacrolimus, sirolimus and everolimus met clinical requirements. Intra-batch coefficients of variation ( CV) were from 1.4% to 1.8% for CSA, from 1.7% to 2.8% for TAC, from 1.3% to 3.7% for SRL and from 2.3% to 3.2% for EVR, and total CVs were from 1.8% to 2.9% for CSA, from 1.7% to 3.8% for TAC, from 2.6% to 4.7% for SRL and from 3.5% to 4.6% for EVR. The relative recoveries were from 97.9% to 100.3% for CSA, from 98.4% to 103.1% for TAC, from 99.4% to 102.0% for SRL and from 98.3% to 99.4% for EVR, and the relative expanded uncertainties at four concentrations were from 4.2% to 4.4% for CSA, from 1.5% to 2.4% for TAC, from 4.4% to 4.9% for SRL and from 2.2% to 2.7% for EVR. Conclusion:A candidate reference measurement procedure for the cyclosporine A, tacrolimus, sirolimus, and everolimus in human whole blood was established by ID-LC-MS/MS.

Objective:The standardized medical device clinical trials in China began in a short time, and the quality of trials needs to be improved.This article intends to explore possible ways for the improvement of quality management of the medical device clinical trials.Methods:Through working practice and literature review, analyze the current status of medical device clinical trials and in vitro diagnostic reagent in China; put forward targeted improved measures for the quality management system; as well as verify its feasibility through practice.Results:This article summarizes three factors that limit the improvement of the quality of medical device clinical trials, including the insufficient research and development strength of sponsors, the limited professional level of research teams, and the differences in verification and drugs, based on the risk-based quality management concepts, puts forward improved measures from three aspects, which including building risk-based quality certification system, making full use of electronic information systems to ensure the trial quality, and strengthening training of clinical trial capacity of researchers, and verifies the feasibility of these measures via the practical experience of our hospital since 2016.Conclusions:The application of risk-based quality management system, electronic information system and clinical trial capacity training can improve the management quality for medical device clinical trial centers.

Objective:To investigate the cognition and knowledge of cardiopulmonary resuscitation (CPR) among primary school students in Guangzhou and to explore the intervention effect of CPR training.Methods:A total of 238 students from a primary school in Guangzhou were selected as the research subjects from April 22 to 26, 2019. In March 2019 (before the training) , a self-made questionnaire was used to conduct a knowledge survey on CPR, and the training methods and contents of CPR were formulated according to the survey results. Knowledge survey was carried out again on the day after every training, and the training effect was evaluated.Results:Before the training, the correct answer rates of 221 elementary school students to the questions about compression only without artificial respiration, emergency call, external chest compression position, compression speed and compression depth were 6.3%, 95.0%, 89.6%, 24.4%, and 24.0%, respectively. After the training, the correct answer rates of 233 primary school students were 59.2%, 99.6%, 99.6%, 63.5% and 70.0%, respectively. The correct rates after training were higher than those before training, and the differences were statistically significant ( P<0.05) . Before and after the training, there was no statistically significant difference in the proportion of students who thought it necessary to learn CPR and were willing to perform CPR on strangers ( P>0.05) . Conclusions:The knowledge and skills of cardiopulmonary resuscitation of primary school students in Guangzhou without cardiopulmonary resuscitation training are low. It is recommended that schools and education departments at all levels pay attention to the promotion and training of first aid skills, formulate training programs suitable for the physical and mental characteristics of primary school students and improve students' self-help and mutual rescue capabilities.