Evaluation of the etiology and risk factors for maternal sepsis: A single center study in Guangzhou, China

BACKGROUND Maternal sepsis is a major cause of gestational morbidity and neonatal mortality worldwide and particularly in China.AIM To evaluate the etiology of maternal sepsis and further identify its risk factors.METHODS In this retrospective study,we evaluated 70698 obstetric patients who were admitted to the Third Affiliated Hospital of Guangzhou Medical University between January 1,2009 and June 30,2018.Subjects were divided into sepsis group and non-sepsis group based on the incidence of sepsis.Data about medical history(surgical and obstetric history)and demographic information were collected.The Mann-Whitney U test was used to compare patient age,gestational age and duration of hospitalization between the two groups.Univariate and multivariate logistic regression models were used to analyze the etiology and the risk factors for maternal sepsis.Unadjusted and adjusted odds ratios(OR)are reported.RESULTS A total of 561 of 70698 obstetric patients were diagnosed with infection;of the infected patients,492 had non-sepsis associated infection(87.7%),while 69 had sepsis(12.3%).The morbidity rate of maternal sepsis was 9.76/10000;the fatality rate in the sepsis group was 11.6%(8/69).Emergency admission(OR=2.183)or transfer(OR=2.870),irregular prenatal care(OR=2.953),labor induction(OR=4.665),cervical cerclage(OR=14.214),first trimester(OR=6.806)and second trimester(OR=2.09)were significant risk factors for maternal sepsis.CONCLUSION Mode of admission,poor prenatal care,labor induction,cervical cerclage,first trimester and second trimester pregnancy were risk factors for maternal sepsis.Escherichia coli was the most common causative organism for maternal sepsis,and the uterus was the most common site of infection.

Activation of AMPK/MnSOD signaling mediates anti-apoptotic effect of hepatitis B virus in hepatoma cells

AIM: To investigate the anti-apoptotic capability of the hepatitis B virus(HBV) in the HepG2 hepatoma cell line and the underlying mechanisms.METHODS: Cell viability and apoptosis were measured by MTT assay and flow cytometry, respectively. Targeted knockdown of manganese superoxide dismutase(Mn SOD), AMP-activated protein kinase(AMPK) and hepatitis B virus X protein(HBx) genes as well as AMPK agonist AICAR and antagonist compound C were employed to determine the correlations of expression of these genes.RESULTS: HBV markedly protected the hepatoma cells from growth suppression and cell death in the condition of serum deprivation. A decrease of superoxide anion production accompanied with an increase of Mn SOD expression and activity was found in Hep G2.215 cells. Moreover, AMPK activation contributed to the up-regulation of Mn SOD. HBx protein was identified to induce the expression of AMPK and Mn SOD. CONCLUSION: Our results suggest that HBV suppresses mitochondrial superoxide level and exerts an antiapoptotic effect by activating AMPK/Mn SOD signaling pathway, which may provide a novel pharmacological strategy to prevent HCC.

Transvaginal 3D Ultrasound Evaluation of Post-Cesarean Section Uterine Diverticulum

Objectives: This study focused on evaluating the value of transvaginal 3D ultrasound for the diagnosis and prognostic assessment of post-cesarean section uterine diverticulum. Materials and Methods: We retrospectively analyzed the data from 32 patients with post-cesarean section uterine diverticulum over three recent years. In all patients, transvaginal 3D ultrasound was used to measure the size of the uterine diverticulum and the thickness of the lower uterine segment (LUS) and myometrium. Patients with a LUS with a myometrial thickness under 4 mm underwent resection and repair surgery;those with a LUS with a myometrial thickness over 4 mm underwent hysteroscopic resection. The postoperative sonograms were compared with preoperative images to evaluate the efficacy of various treatments. Results: The mean length, width and depth of the uterine diverticula were 18.30 ± 2.80 mm, 9.14 ± 3.20 mm and 11.49 ± 2.71 mm, respectively. The average LUS myometrial thickness was 3.40 ± 0.80 mm (with a range of 1.6 mm - 6.3 mm). After surgery, two patients’ sonograms still showed diverticula at the post-cesarean section scar, measuring 6 mm × 7 mm × 6 mm and 6 mm × 8 mm × 4 mm. There were significant differences in the size of uterine diverticula between preoperative and postoperative sonograms (P < 0.05) and the effective rate of surgery was 93.75% (30/32). Conclusions: Transvaginal 3D ultrasound is an accurate method for detecting post-cesarean section uterine diverticulum and is helpful for assessing surgical options and prognosis. The LUS myometrial thickness, which is considered as an optional index of post-cesarean section uterine diverticulum, should be measured routinely.

Management of Ectopic Pregnancy in a Broad Ligament and Recurrent Tubal Pregnancy: A Case Report

Broad ligament pregnancy is a rare event and always delays in diagnosis. A pregnant woman in early twenties presented for our center. Routine ultra-sonography revealed a first trimester abdominal pregnancy. Broad ligament pregnancy was diagnosed intraoperation and treated with laparoscopic resection successfully. The patient has a history of right tubal pregnancy 2 years ago and terminated with Laparoscopic Salpingostomy. According to the long term followed-up for the patient, we found that she had recurrent right tubal pregnancy 5 months after the broad ligment ectopic pregnancy. She received the salpingectomy laparoscopically. We presented the case to discuss the clinical management of broad ligament ectopic pregnancy and options of surgical treatments of tubal pregnancy to reduce the risk of recurrent.

Is the Trial of Labor after Two Previous Cesarean Sections Contraindicated in China?

The cesarean section(CS) rate has risen rapidly worldwide. In high-income countries, national studies have revealed that more than a quarter of births are performed by CS, while in China the rate increased from 28.8% in 2008 to 34.9% in2014[1]—far above the World Health Organization(WHO)-recommended rate of 10%–15%. Due to the high global cesarean rates, the promotion of trial of labor after cesarean(TOLAC) may be an option that can be used to reduce the overall number of CSs.

The potential role of the “cold chain” in the spread of SARS-CoV-2

Direct transmission of SARS-CoV-2 involves two main aspects:it can occur by inhaling either droplets or aerosols in the air containing viruses.In addition,viruses can also spread after being deposited on inanimate surfaces.Recently,there were reports suggested that SARS-CoV-2 can be found in frozen products.The cold chain creates opportunities for the spread of SARS-CoV-2.With the advent of winter,the drop in outside temperature makes the“frozen chain”less likely to be destroyed;thus,the virus will survive longer on frozen products.During the transportation of imported food,there is a greater risk of virus infection.Therefore,we should be vigilant and strengthen the quarantine of each type of imported food.

Villous Capillary Malformation and Intermediate Trophoblast Invasiveness:Histopathologic Findings From Fetomaternal Hemorrhage with Gestational Choriocarcinoma

To editor:Fetomaternal hemorrhage(FMH)refers to the fetal blood transfection into the maternal circulation,usually involving a bleeding volume exceeding 30 ml.This phenomenon can promptly trigger a sinusoidal fetal heart rate pattern,posing a significant risk of life-threatening fetal anemia and even mortality1,2 Upon suspicion of FMH,immediate intervention is essential to prevent neonatal death,often leading to the insufficient recognition of placental examination in many published reports.However,an increasing number of FMH case reports have underscored the potential subsequent risk of choriocarcinoma.

Human germline editing: Insights to future clinical treatment of diseases

Last year, the first attempt to genetically modify human embryos in the United States was reported and sparked a huge debate (Ma et al., 2017). Although the first human germline modification was only performed two years ago, the study showed that rapid adva nces in tech no logy has allowed the rate of off-target effects and mosaicism to be reduced considerably (Liang et al., 2015). Recently, Vertex and CRISPR therapeutics collaborated and developed CTX001, the first CRISPR/Cas9-based therapy, targeting patients with P-thalassemia and have begun phase 1/2 clinical trials. With policies and technologies regarding genome editing both developing rapidly, explorations into the possibility of clinical gene editing for hundreds of hereditary diseases are starting to become achievable. Here, we address the progress of huma n embryo editi ng tech no logies so far and its promise and risks in advancing therapy for hereditary diseases.

A conserved region in the 3' untranslated region of the human LIMK1 gene is critical for proper expression of LIMK1 at the post-transcriptional level

LIM kinase 1 （LIMK1）, a cytosolic serine/threonine kinase, regulates actin filament dynamics and reorganization and is involved in neuronal development and brain function. Abnormal expression of LIMK1 is associated with several neurological disorders. In this study, we performed a conservation analysis using Vector NTI （8.0） software. The dualluciferase reporter assay and real-time quantitative RT-PCR were used to assess the protein and mRNA levels of the reporter gene, respectively. We found that a region ranging from nt ＋884 to ＋966 in the human LIMK1 3＇ untranslated region （UTR） was highly conserved in the mouse Limkl 3＇ UTR and formed a structure containing several loops and stems. Luciferase assay showed that the relative luciferase activity of the mutated construct with the conserved region deleted, pGL4-hLIMK1-3U-M, in SH-SY5Y and HEK-293 cells was only -60% of that of the wild-type construct pGL4-hLIMK1-3U, indicating that the conserved region is critical for the reporter gene expression. Real-time quantitative RT-PCR analysis demonstrated that the relative Luc2 mRNA levels in SH-SY5Y and HEK293 cells transfected with pGL4-hLIMK1-3U-M decreased to50% of that in cells transfected with pGL4-hLIMK1- 3U, suggesting an important role of the conserved region in maintaining Luc2 mRNA stability. Our study suggests that the conserved region in the LIMK1 3＇ UTR is involved in regulating LIMK1 expression at the post-transcriptional level, which may help reveal the mechanism underlying the regulation of LIMK1 expression in the central nervous system and explore the relationship between the 3＇-UTR mutant and neuroloqical disorders.

Clinicopathologic characteristics of primary vaginal clear cell carcinoma in China and an endometriosis malignant transformation case: a case series

To the Editor:Primary vaginal carcinoma is a rare malignant disease,which represents only approximately 1%to 2%of female genital malignancies.Vaginal adenosis is defined by the presence of metaplastic cervical or endometrial epithelium within the vaginal wall,and is associated with a high risk of vaginal carcinoma.In women prenatally exposed to diethylstilboestrol(DES),vaginal adenosis may arise in up to 90%,and these are often associated with vaginal clear cell adenocarcinoma.[1]DES is an orally active non-steroidal estrogen.The Food and Drug Administration began a clinical trial in 1943,and concluded that DES administration is beneficial for preventing premature deliveries and miscarriages.[2]In addition to primary vaginal clear cell carcinoma(PVCCC),in-uterus exposure to DES can also lead to T-shaped uterus anomaly.[3]In the Chinese population,PVCCC is an uncommon malignancy,and there are no reports on the relationship between PVCCC and DES exposure.[4]Given the rarity of PVCCC,it is significant to analyze relevant cases,and provide some valuable information for future clinical and basic studies.Therefore,the present study described ten cases of PVCCC,and summarized the characteristics of the diagnosis,management,and prognosis of these patients.

Genome wide abnormal DNA methylome of human blastocyst in assisted reproductive technology

Proper reprogramming of parental DNA methylomes is essential for mammalian embryonic development. However, it is unknown whether abnormal methylome reprogramming occurs and is associated with the failure of embryonic development. Here we analyzed the DNA methylomes of 57 blastocysts and 29 trophectoderm samples with different morphological grades during assisted reproductive technology （ART） practices. Our data reveal that the global methylation levels of high-quality blastocysts are similar （0.30 ± 0.02, mean ± SD）, while the methylation levels of low-quality blastocysts are divergent and away from those of high-quality blastocysts. The proportion of blastocysts with a methylation level falling within the range of 0.30± 0.02 in different grades correlates with the live birth rate for that grade. Moreover, abnormal methylated regions are associated with the failure of embryonic development. Furthermore, we can use the methylation data of cells biopsied from trophectoderm to predict the blastocyst methylation level as well as to detect the aneuploidy of the blastocysts. Our data indicate that global abnormal methylome reprogramming often occurs in human embryos, and suggest that DNA methylome is a potential biomarker in blastocyst selection in ART.

Neuroendocrine characteristics of induced pluripotent stem cells from polycystic ovary syndrome women

Dear Editor, Polycystic ovary syn drome (PCOS) is a comm on female reproductive endocrinopathy that afflicts up to 10%-15% of women in reproductive age worldwide (Nestler, 2016). Women with PCOS exhibit hyperandrogenism, intermittent/ absent menstrual cycles, and polycystic ovaries on ultrasound (Rotterdam, 2004). The pathophysiology of PCOS extends beyond infertility and hirsutism to hypothalamic neuroendocrine dysfunotion (Goodarzi et al., 2011). Most wome n with PCOS exhibit in creased luteinizing horm one (LH) levels, resulting from high-frequency gonadotropin-releasing hormone (GnRH) secretion (Cimino et al., 2016). Pren ata I testostero ne (T) treatment in sheep results in disrupted steroid feedback on gonadotropin release, which in creases pituitary sen sitivity to GnRH and subseque ntly leads to LH hypersecretion (Sullivan and Moenter, 2004;Cardoso et al., 2016). A recent study shows that GnRHdependent LH pulsatility and secretion are elevated by anti- Mullerian hormone (AMH) in PCOS disease. The increased prenatal AMH reprograms fetus and induces PCOS in adults (Tata et al., 2018). Furthermore, the androgen receptor (AR) plays a role in hyperandrogenism and ovarian folliculoge esis in PCOS (Wang et al., 2015;Abbott, 2017). However, the disease mechanism behind PCOS remains unclear, and current management focuses on treating the symptoms but not the mechanism (Chen et al., 2016;Shi et al., 2018). A further understanding of this disease is necessary to uncover the pathology of PCOS and develop new potential therapeutic avenues and drugs.

Influence of gonadotropin-releasing hormone agonist on the effect of chemotherapy upon ovarian cancer and the prevention of chemotherapy-induced ovarian damage:an experimental study with nu/nu athymic mice

Background and objective:Gonadotropin-releasing hormone (GnRH) plays an important role in the regulation of ovarian function and ovarian cancer cell growth. In this study, we determined whether administration of the GnRH agonist (GnRHa), triporelin, prior to cisplatin treatment affects cisplatin and/or prevents cisplatin-induced ovarian damage. Methods:nu/nu mice were injected with ovarian cancer OVCAR-3 cells intraperitoneally. After two weeks, the mice were treated with saline (control), cisplatin, GnRHa, or cisplatin plus GnRHa for four weeks. At the end of the experimental protocol, blood, tumor, ovary, and uterine tissues were resected for hematoxylin and eosin (H&E) staining, immunohistochemical analyses of Ki67, nuclear factor-κB (NF-κB), and caspase-3, transmission electron microscopy of apoptosis, or enzyme-linked immunosorbent assay (ELISA) analyses of anti-Mullerian hormone (AMH). Results:Cisplatin treatment effectively inhibited tumor growth in mice treated with human ovarian cancer cells; however the treatment also induced considerable toxicity. Immunohistochemical analyses showed that Ki67 expression was reduced in cisplatin-treated mice compared to control (P<0.05), but there was no statistically significant differences between cisplatin-treated mice and cisplatin plus GnRHa-treated mice (P>0.05), while expressions of NF-κB and caspase-3 were reduced and induced, respectively, in cisplatin-treated mice and cisplatin plus GnRHa-treated mice. Apoptosis occurred in the GnRHa, cisplatin, and cisplatin plus GnRHa-treated mice, but not in control mice. Ovaries exposed to GnRHa in both GnRHa mice and cisplatin-treated mice (combination group) had significantly more primordial and growth follicles and serum levels of AMH than those in the control mice and cisplatin-treated mice (P<0.05). Conclusions:Administration of GnRHa to mice significantly decreased the extent of ovarian damage induced by cisplatin, but did not affect the anti-tumor activity of cisplatin.

Fargeted elimination of mutant mitochondria DNA in MELAS-iPSCs by mitoTALENs

Mitochondrial diseases are maternally inherited hetero- geneous disorders that are primarily caused by mitochondrial DNA （mtDNA） mutations. Depending on the ratio of mutant to wild-type mtDNA, known as heteroplasmy, mitochondrial defects can result in a wide spectrum of clinical manifestations. Mitochondria-targeted endonucleases provide an alternative avenue for treating mitochondrial disorders via targeted destruc- tion of the mutant mtDNA and induction of heteroplasmic shifting. Here, we generated mitochondrial disease patient-specific induced pluripotent stem cells （MiPSCs） that harbored a high proportion of m.3243A〉G mtDNA mutations and caused mitochondrial encephalomyopathy and stroke-like episodes （MELAS）. We engineered mitochondrial-targeted transcription activator-like effector nucleases （mitoTALENs） and successfully eliminated the m.3243A〉G mutation in MiPSCs. Off-target mutagenesis was not detected in the targeted MiPSC clones. Utilizing a dual fluorescence iPSC reporter cell line expressing a 3243G mutant mtDNA sequence in the nuclear genome, mitoTALENs displayed a significantly limited ability to target the nuclear genome compared with nuclear-localized TALENs. Moreover, genetically rescued MiPSCs displayed normal mitochondrial respiration and energy production. Moreover, neuronal progenitor cells differentiated from the rescued MiPSCs also demonstrated normal metabolic profiles. Further- more, we successfully achieved reduction in the human m.3243A〉G mtDNA mutation in porcine oocytes via injection of mitoTALEN mRNA. Our study shows the great potential for using mitoTALENs for specific targeting of mutant mtDNA both in iPSCs and mammalian oocytes, which not only provides a new avenue for studying mitochondrial biology and disease but also suggests a potential therapeutic approach for the treatment of mitochondrial disease, as well as the prevention of germline transmission of mutant mtDNA.

Modes of genetic adaptations underlying functional innovations in the rumen

The rumen is the hallmark organ of ruminants and hosts a diverse ecosystem of microorganisms that facilitates efficient digestion of plant fibers.We analyzed 897 transcriptomes from three Cetartiodactyla lineages:ruminants,camels and cetaceans,as well as data from ruminant comparative genomics and functional assays to explore the genetic basis of rumen functional innovations.We identified genes with relatively high expression in the rumen,of which many appeared to be recruited from other tissues.These genes show functional enrichment in ketone body metabolism,regulation of microbial community,and epithelium absorption,which are the most prominent biological processes involved in rumen innovations.Several modes of genetic change underlying rumen functional innovations were uncovered,including coding mutations,genes newly evolved,and changes of regulatory elements.We validated that the key ketogenesis rate-limiting gene(HMGCS2)with five ruminant-specific mutations was under positive selection and exhibits higher synthesis activity than those of other mammals.Two newly evolved genes(LYZ1 and DEFB1)are resistant to Gram-positive bacteria and thereby may regulate microbial community equilibrium.Furthermore,we confirmed that the changes of regulatory elements accounted for the majority of rumen gene recruitment.These results greatly improve our understanding of rumen evolution and organ evo-devo in general.

Correction to: Neuroendocrine characteristics of induced pluripotent stem cells from polycystic ovary syndrome women

In the original publication the Fig.2 and the Supplementary Material 1 was incorrect.The correct version of Fig.2 and the Supplementary Material are provided in this correction article.NESTIN should be corrected to PAX6 in Fig.2C legend and at page 528 and Supplementary Material 1.NANOG should be corrected to PAX6 in Fig.2C picture.

Related Factors of in vitro Fertilization and Embryo Transfer Patients with Complete Fertilization Failure

Objective To find the possible factors predicting fertilization failure of in vitro fertilization-embryo transfer （1VF-ET）. Methods The IVF-ET patients with complete fertilization failure （experimental group, n =32） were analyzed retrospectively. The patients whose oocytes retrieved at the same day and cultured on the same incubators with ≥ 50% fertilization rates were matched as the control （n=56）. Results The infertility duration, superovulation days, the rates of primary case, progesterone （P） level 〉3.12 nmol/L rate and rate of severe abnormal sperm （abnormal sperm rate 〉95%） in experimental group were significantly higher than those in the control （6.4 ±3.1 years, 12.6 ±2.2 d, 56%, 43%, 43% vs 4.6±2.9years, 11.6 ±% 1.3 d, 33%, 23%, 23%, respectively, P〈0.05）. Conclusion We should pay attention to these patients with primary infertility, longer infertility duration and superovulation days （〉6.4 years and 〉12.6 d） and having increased level of P on hCG injection day （〉3.12 nmol/L）, abnormal sperm rate 〉95% at the same time. They should be included in such patients at high risk of fertilization failure.

Chlamydia trachomatis infection in the genital tractis associated with inflammation and hypospermia inthe infertile male of China

Chlamydia trachomatis (CT) infection is the most prevalent sexually transmitted bacterial disease worldwide. However, unlikethat in female infertility, the role of CT infection in male infertility remains controversial. The objective of this retrospective studywas to explore the impacts of CT infection in the genital tract on sperm quality, sperm acrosin activity, antisperm antibody levels,and inflammation in a large cohort of infertile males in China. A total of 7154 semen samples were collected from infertile malesubjects, 416 of whom were CT positive (CT+ group) and 6738 of whom were CT negative (CT− group), in our hospital betweenJanuary 2016 and December 2018. Routine semen parameters (semen volume, pH, sperm concentration, viability, motility,morphology, etc.), granulocyte elastase levels, antisperm antibody levels, and sperm acrosin activity were compared between theCT+ and CT− groups. Our results showed that CT infection was significantly correlated with an abnormally low semen volume, aswell as an increased white blood cell count and granulocyte elastase level (all P < 0.05) in the semen of infertile males;otherroutine semen parameters were not negatively impacted. The antisperm antibody level and sperm acrosin activity were not affectedby CT infection. These findings suggested that CT infection might contribute to inflammation and hypospermia but does not impairsperm viability, motility morphology, and acrosin activity or generate antisperm antibodies in the infertile males of China.

Maternal high salt-diet increases offspring's blood pressure with dysfunction of NO/PKGI signaling pathway in heart tissue

Background:High salt-diets have become significant threats to human health,resulting in hypertension and cardiovascular diseases.Hypertensive disorders during pregnancy are complicated,since the maternal cardiovascular system undergoes extensive physiological changes during pregnancy.High-salt diets during pregnancy can disturb the intrauterine environment and negatively affect fetal development.Therefore,we explored how high-salt diets during pregnancy could affect the offspring.Methods:Rats were divided into three groups and fed with low,normal,and high salt diets.The offspring were separated into three groups after weaning based on dietary salt concentration.The blood pressure and urine protein content of both dams and offspring were measured.To evaluate cardiac function,we used Masson staining and immunodetection to confirm the fibrosis status.Finally,we extracted protein from cardiac tissue to test the expression levels of the Nitric Oxide(NO)/cGMP-dependent protein kinase I(PKGI)pathway and the angiotensin receptor.Results:High-salt diets increased blood pressure,and offspring previously exposed to high-salt environments were predisposed to hypertension.High-salt diets were also found to induce cardiac fibrosis and exacerbate fibrosis in offspring and alter the epithelial-mesenchymal transition(EMT).Under these conditions,the NO/PKGI pathway was activated in cardiac tissue and the type-1angiotensin II receptor(AT1R)was upregulated,though the type-2 angiotensin II receptor(AT2R)had the opposite effect.Conclusion:High-salt diets induce high blood pressure and increase predisposition to hypertension in offspring.They are accompanied by cardiac fibrosis,which could be caused by the activation of NO/PKGI and upregulation of AT1R.

Risk Factors and Pregnancy Outcome in Women with a History of Cesarean Section Complicated by Placenta Accreta

Objective:To explore the risk factors and pregnancy outcomes in women with a history of cesarean section complicated by placenta accreta(PA).Methods:This case-control study included clinical data from singleton mothers with a history of cesarean section in 11 public tertiary hospitals in seven provinces of China between January 2017 and December 2017.According to the intraoperative findings after delivery,the study population was divided into PA and non-PA groups.We compared the pregnancy outcomes between the two groups,used multivariate logistic regression to analyze the risk factors for placental accreta.Results:For this study we included 11,074 pregnant women with a history of cesarean section;and of these,869 cases were in the PA group and 10,205 cases were in the non-PA group.Compared with the non-PA group,the probability of postpartum hemorrhage(236/10,205,2.31%vs.283/869,32.57%),severe postpartum hemorrhage(89/10,205,0.87%vs.186/869,21.75%),diffuse intravascular coagulation(3/10,205,0.03%vs.4/869,0.46%),puerperal infection(33/10,205,0.32%vs.12/869,1.38%),intraoperative bladder injury(1/10,205,0.01%vs.16/869,1.84%),hysterectomy(130/10,205,1.27%vs.59/869,6.79%),and blood transfusion(328/10,205,3.21%vs.231/869,26.58%)was significantly increased in the PA group(P<0.05).At the same time,the neonatal birth weight 3250.00(2950.00–3520.00)g vs.2920.00(2530.00–3250.00)g),the probability of neonatal comorbidities(245/10,205,2.40%vs.61/869,7.02%),and the rate of neonatal intensive care unit admission(817/10,205,8.01%vs.210/869,24.17%)also increased significantly(P<0.05).Weight(odds ratio)(OR)=1.03,95%confidence interval(CI):1.01–1.05)),parity(OR=1.18,95%CI:1.03–1.34),number of miscarriages(OR=1.31,95%CI:1.17–1.47),number of previous cesarean sections(OR=2.57,95%CI:2.02–3.26),history of premature rupture of membrane(OR=1.61,95%CI:1.32–1.96),previous cesarean-section transverse incisions(OR=1.38,95%CI:1.12–1.69),history of placenta previa(OR=2.44,95%CI:1.50–3.96),and the combination of prenatal hemorrhage(OR=9.95,95%CI:8.42–11.75)and placenta previa(OR=91.74,95%CI:74.11–113.56)were all independent risk factors for PA.Conclusion:There was an increased risk of adverse outcomes in pregnancies complicated by PA in women with a history of cesarean section,and this required close clinical attention.Weight before pregnancy,parity,number of miscarriages,number of previous cesarean sections,history of premature rupture of membranes,past transverse incisions in cesarean sections,a history of placenta previa,prenatal hemorrhage,and placenta previa were independent risk factors for pregnancies complicated with PA in women with a history of cesarean section.These independent risk factors showed a high value in predicting the risk for placentab accreta in pregnancies of women with a history of cesarean section.