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Placenta accreta spectrum disorder (PAS) is a kind of disease of placentation defined as abnormal trophoblast invasion of part or all of the placenta into the myometrium, even penetrating the uterus. Decidual deficiency, abnormal vascular remodeling in the maternal–fetal interface, and excessive invasion by extravillous trophoblast (EVT) cells contribute to its onset. However, the mechanisms and signaling pathways underlying such phenotypes are not fully understood, partly due to the lack of suitable experimental animal models. Appropriate animal models will facilitate the comprehensive and systematic elucidation of the pathogenesis of PAS. Due to the remarkably similar functional placental villous units and hemochorial placentation to humans, the current animal models of PAS are based on mice. There are various mouse models induced by uterine surgery to simulate different phenotypes of PAS, such as excessive invasion of EVT or immune disturbance at the maternal–fetal interface, which could define the pathological mechanism of PAS from the perspective of the “soil.” Additionally, genetically modified mouse models could be used to study PAS, which is helpful to exploring the pathogenesis of PAS from the perspectives of both “soil” and “seed,” respectively. This review details early placental development in mice, with a focus on the approaches of PAS modeling. Additionally, the strengths, limitations and the applicability of each strategy and further perspectives are summarized to provide the theoretical foundation for researchers to select appropriate animal models for various research purposes. This will help better determine the pathogenesis of PAS and even promote possible therapy.

ObjectiveThis study aims to evaluate the importance of the gestational age at diagnosis and the types of cesarean scar pregnancy (CSP) for treatment outcomes and to identify the optimal treatment based on both the gestational age at diagnosis and the CSP type.MethodsA retrospective cohort study included 223 pregnant women diagnosed with CSP at Peking University First Hospital, Beijing, China, between 2014 and 2018. All CSP cases underwent ultrasound-guided vacuum aspiration followed by supplementary curettage. Adjuvant treatment modalities included intramuscular injection of systemic methotrexate, uterine artery embolization, and hysteroscopy before ultrasound-guided vacuum aspiration. Linear regression was used to determine the relationship between intraoperative blood loss and gestational age at diagnosis, CSP type, highest β-human chorionic gonadotropin level, and management procedures.ResultsNone of the patients required blood transfusions or hysterectomies. Patients presenting at 10 weeks had median estimated blood loss of 5, 10, and 35 ml, respectively. Patients with type I CSP, type II CSP, and type III CSP had median blood loss of 5, 5 and 10 ml, respectively. Multivariate linear regression analysis demonstrated that the gestational age at diagnosis (p p = 0.023) were independent predictors of intraoperative estimated blood loss. For type I CSP patients, ultrasound-guided vacuum aspiration followed by supplementary curettage alone was performed in 15 of 34 (44.1%) patients, including 12/27 (44.4%) diagnosed at 10 weeks. In type II CSP patients, fewer cases were managed by ultrasound-guided vacuum aspiration followed by supplementary curettage alone as the gestational age at diagnosis increased [18/96 (18.8%) for 10 weeks]. Most type III CSP patients (41/45, 91.1%) needed treatments in addition to the ultrasound-guided vacuum aspiration regardless of the gestational age at diagnosis. All CSP patients were treated successfully and did not require readmission or further medical interventions.ConclusionGestational age at diagnosis of CSP and its type show a strong correlation with estimated blood loss during ultrasound-guided vacuum aspiration. With careful management, CSPs may be treated at any gestational week, regardless of their type, with minimal intraoperative bleeding.

BackgroundGut microbiota of pregnant women change with the gestational week. On the one hand, they participate in the metabolic adaptation of pregnant women. On the other hand, the abnormal composition of gut microbiota of pregnant women is more likely to suffer from gestational diabetes mellitus (GDM). Therefore, gut microbiota targeted treatment through dietary supplements is particularly important for prevention or treatment. Prebiotic supplements containing galactooligosaccharides (GOS) may be an intervention method, but the effect is still unclear.ObjectiveThis study aims to evaluate the feasibility and acceptability of prebiotic intervention in healthy pregnant women during pregnancy, and to explore the possible effects of intervention on pregnant women and the influence on gut microbiota as preliminaries.MethodsAfter recruitment in first trimester, 52 pregnant women were randomly assigned to receive GOS intervention or placebo containing fructooligosaccharides. 16S rRNA sequencing technology was used to detect the composition, diversity and differential flora of gut microbiota. Lipid metabolism, glucose metabolism and inflammatory factors during pregnancy were also analyzed.ResultsThe adverse symptoms of GOS intervention are mild and relatively safe. For pregnant women, there was no significant difference in the GDM incidence rates and gestational weight gain (GWG) in the GOS group compared with placebo (P > 0.05). Compared with the placebo group, the levels of FPG, TG, TC, HDL-C LDL-C, and IL-6 had no significant difference in GOS group (P > 0.05). For newborns, there was no significant difference between GOS group and placebo group in the following variables including gestational week, birth weight, birth length, head circumference, chest circumference, sex, and delivery mode (P > 0.05). And compared with the placebo group, the GOS group had a higher abundance of Paraprevotella and Dorea, but lower abundance of LachnospiraceaeUCG_001.ConclusionsGOS prebiotics appear to be safe and acceptable for the enrolled pregnancies. Although GOS intervention did not show the robust benefits on glucose and lipid metabolism. However, the intervention had a certain impact on the compostion of gut microbiota. GOS can be considered as a dietary supplement during pregnancy, and further clinical studies are needed to explore this in the future.

BackgroundIt remained controversial whether women with multiple gestation are at higher risk of placenta accreta spectrum (PAS) disorders and large-scale studies are needed. This study aimed to assess whether PAS incidence is higher among women with multiple gestation than among singleton, as well as to compare the characteristics and outcomes of PAS in multiple and singleton gestation.MethodsWomen who underwent cesarean section with live births at Peking University First Hospital from January 2015 to December 2020 were included. Demographic and clinical information was collected through chart review. Logistic regression models were used to analyze the associations between multiple gestation and PAS. The clinical characteristics and perioperative outcomes of PAS in multiple and singleton gestation were further compared.ResultsAmong the 14583 women included, 2.4% (352/14583) were diagnosed with PAS. PAS was slightly more prevalent among multiple gestations than among singletons (2.5% vs 2.4%, P=0.857). After adjusting for known risk factors and pregnancy complications, multiple gestation was associated with a higher risk of PAS (aOR=1.63, 95% CI 1.01-2.62). Among PAS patients, women who had multiple births had a significantly lower rate of previous cesarean deliveries (27.6% vs. 56.3%, P=0.003), placenta previa (17.2% vs. 56.3%, PP=0.002) than singletons. There were no significant differences in perioperative outcomes between these two groups.ConclusionMultiple gestation could be independently associated with an elevated risk of PAS. The clinical characteristics of PAS in the multiple and singleton gestation groups differed significantly in cesarean delivery history and placenta previa. The results of this study may inform guidelines on the screening, early detection and timely intervention of PAS patients among women with multiple births.