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.

Objective:To investigate the variation of reference ranges of hemodynamic parameters in normal pregnancy and their relation to maternal basic characteristics.Methods:A total of 598 healthy pregnant women who underwent regular prenatal examination at the Third Affiliated Hospital of Guangzhou Medical University from January to December 2023 were prospectively enrolled, and noninvasive hemodynamic monitors were used to detect changes in hemodynamic parameters of the pregnant women with the week of gestation, including cardiac output (CO), stroke volume (SV), thoracic fluid content (TFC), systemic vascular resistance (SVR), mean arterial pressure (MAP), and heart rate (HR). Relationships between hemodynamic parameters and maternal basic characteristics, including age, height, and weight, were analyzed using restricted cubic spline.Results:(1) CO ( r=0.155, P<0.001), TFC ( r=0.338, P<0.001), MAP ( r=0.204, P<0.001), and HR ( r=0.352, P<0.001) were positively correlated with the week of gestation, and SV was negatively correlated with the week of gestation ( r=-0.158, P<0.001). There was no significant correlation between SVR and gestational age ( r=-0.051, P=0.258). (2) CO exhibited a positive correlation with maternal height and weight (all P<0.001). The taller and heavier of pregnant women, the higher their CO. A linear relationship was observed between maternal weight and SV, MAP and HR (all P<0.01). As maternal weight increased, SV, MAP and HR showed an upward trend. Furthermore, there was an inverse association between maternal age and SVR ( P<0.001). (3) There was a significant nonlinear association observed between TFC and body mass index during pregnancy ( P<0.05). Additionally, a nonlinear relationship was found between SVR and MAP in relation to maternal age (all P<0.05). Notably, when the age exceeded 31 years old, there was an evident upward trend observed in both SVR and MAP. Conclusions:The hemodynamic parameters of normal pregnant women are influenced by their height, body weight, and age. It is advisable to maintain a reasonable weight during pregnancy and give birth at an appropriate age.

N-acetyltransferase10(NAT10)is a protein widely expressed in a variety of tissues and cells.The high expression of NAT10 is closely related to tumor invasion,metastasis and drug resistance.The mechanism of NAT10 promoting tumor genesis and development involves the regulation of cell cycle,mRNA stability,translation efficien-cy and related pathways due to the changes in the expression or location of NAT10,thus affecting the occurrence,development and prognosis of tumors.

Placental implantation disease (PAS) is a pregnancy complication caused by abnormal invasion of trophoblasts. Recently, the incidence rate of PAS has been increasing, which often leads to serious adverse outcomes. Prenatal prediction is of great significance for the safe delivery of PAS patients. Cesarean section and placenta previa are the most common high-risk factors for PAS. Doppler ultrasound is the preferred imaging examination method for predicting the diagnosis of PAS. Magnetic resonance imaging (MRI), as a supplementary method for predicting PAS, has been increasingly used in recent years. The biomarkers detected in maternal serum can also predict PAS during pregnancy. The prediction of PAS by medical history, imaging examinations, and biomarkers will be a hot topic in future research.

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.

Preeclampsia, a serious complication in pregnancy, is a "placental disease" in obstetrics. The growth and development of human and other mammalian embryos are closely related to the placenta. This review summarizes several models for studying preeclampsia including in vitro cell models, placental explants, organoid models, rodent models and primates models, contributing to a deeper understanding of placental development and related pregnancy disorders.

A goal of reducing the maternal mortality to less than 12/100 000 by 2030 is proposed in China. In order to achieve this goal, the need to promote the development of obstetric critical care medicine becomes evident. This article reviews the development history of Chinese obstetric critical care medicine, highlights the necessity and urgency of establishing treatment centers for critical pregnant women and obstetric intensive care units, and puts forward some thoughts for moving the field forward, including attaching the importance to the individualized treatment of obstetric critical patients and development of obstetric intensive care units.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has spread worldwide and threatened human's health. With the passing of time, the epidemiology of coronavirus disease 2019 evolves and the knowledge of SARS-CoV-2 infection accumu-lates. To further improve the scientific and standardized diagnosis and treatment of maternal SARS-CoV-2 infection in China, the Chinese Society of Perinatal Medicine of Chinese Medical Association commissioned leading experts to develop the Recommendations for the Diagnosis and Treatment of Maternal SARS-CoV-2 Infection under the guidance of the Maternal and Child Health Department of the National Health Commission. This recommendations includes the epidemiology, diagnosis, management, maternal care, medication treatment, care of birth and newborns, and psychological support associated with maternal SARS-CoV-2 infection. It is hoped that the recommendations will effectively help the clinical management of maternal SARS-CoV-2 infection.

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.