Application of real-time PCR-based multicolor melting curve with automatic analysis system in pregestational and prenatal thalassemia diagnoses.

BACKGROUND: To evaluate the value of the real-time PCR-based multicolor melting curve analysis (MMCA) with an automatic analysis system used in a mass thalassemia screening and prenatal diagnosis program. METHODS: A total of 18,912 peripheral blood samples from 9456 couples and 1150 prenatal samples were detected by MMCA assay. All prenatal samples were also tested by a conventional method. Samples with unknown melting peaks, unusual peak height ratios between a wild allele and a mutant allele, or a discordant phenotype-genotype match were further studied by using multiplex ligation-dependent probe amplification (MLPA) or Sanger sequencing. All MMCA results were automatically analyzed and manually checked. The consistency between MMCA assay and conventional methods among prenatal samples was investigated. RESULTS: Except for initiation codon (T > G) (HBB:c.2T > G), all genotypes of thalassemia inside the scope of conventional methods were detected by MMCA assay. Additionally, 27 carriers with 10 rare HBB variants, 13 with α fusion gene, 1 with a rare deletion in α globin gene, and 1 with rare HBA variant were detected by using MMCA assay. CONCLUSION: MMCA can be an alternative approach used in routine thalassemia carrier screening and prenatal diagnosis for its high throughput, sufficient stability, low cost, and easy operation.

Utilization of multiple genetic methods for prenatal diagnosis of rare thalassemia variants.

Background: Thalassemia is the most prevalent monogenic disorder caused by an imbalance between the α- and ß-globin chains as a result of pathogenic variants in the α- or ß-globin genes. Novel or complex structural changes in globin genes are major hurdles for genetic consulting and prenatal diagnosis. Methods: From 2020 to 2022, genetic analysis was performed on 1,316 families suspected of having children with thalassemia major, including 42 pregnant couples suspected of being thalassemia carriers with rare variants. Multiple techniques including multiplex ligation-dependent probe amplification (MLPA), Sanger sequencing, targeted next-generation sequencing, and single-molecule real-time (SMRT) sequencing were used to diagnose rare thalassemia. Results: The rate of prenatal diagnosis for rare thalassemia variants was 3.19% (42/1,316). The most prevalent alleles of α- and ß-thalassemia are Chinese Gγ(Aγδß)0and -- THAI deletion. In addition, ten rare complex genotypes include one Chinese Gγ(Aγδß)0 deletion combined with HBG1-HBG2 fusion, two rare deletions at HBB gene (hg38, Chr11: 5224211-5232470, hg38, Chr11: 5224303-5227790), one complete 7,412 bp fusion gene for anti-Lepore Hong Kong, two complex rearrangements of the α-globin gene cluster, two novel duplications, and two rare large deletions in the α-globin gene cluster. Conclusion: Accurate gene diagnosis for probands with combined molecular biology techniques is the key to prenatal diagnosis of rare thalassemia.

Defined, low threshold for caesarean section and multidisciplinary team management improves fetal outcome from acute pancreatitis in pregnancy.

BACKGROUND: Acute pancreatitis in pregnancy (APIP) is associated with increased maternal and fetal mortality. OBJECTIVES: We sought to determine whether a low threshold for cesarean section (C-section) in severe acute pancreatitis (SAP) or Predict SAP improves maternal and fetal outcomes in patients with APIP. METHODS: We identified patients with APIP at a single institution from a prospective database and studied fetal and maternal health in APIP before (2005-2014) and after (2015-2019) introduction of multidisciplinary team management with a defined, lowered threshold for C-section. The primary end point was fetal mortality comprising abortion and perinatal death. Risk factors associated with fetal mortality were analyzed by univariable and multivariable logistic regression analysis. RESULTS: A total of 165 patients with APIP were eligible for analysis. There was a highly significant increase in patients undergoing C-section from 37 (30.8%) of 120 during 2005-2014 to 27 (60%) of 45 in 2015-2019 (P = 0.001), with a highly significant fall in fetal mortality from 37 (30.8%) of 120 to 3 (6.7%) of 45 between the same periods (P = 0.001), when maternal mortality fell from 6 to zero (P = 0.19). Maternal early systemic inflammatory response syndrome (SIRS) (odds ratio [OR] 6.98, 95% confidence interval [CI] 1.53, 30.80, P = 0.01) and SAP (OR 3.64, 95%CI 1.25, 10.60, P = 0.02) were two independent risk factors associated with fetal mortality. CONCLUSIONS: Multidisciplinary collaboration and a defined, low threshold for C-section improve fetal outcomes in patients with APIP.

Clinical impacts of genome-wide noninvasive prenatal testing for rare autosomal trisomy.

BACKGROUND: Genome-wide noninvasive prenatal testing identifies several rare autosomal trisomies in the general obstetrical population, but its use is questioned by its low positive predictive value. Furthermore, the origin of rare autosomal trisomies and the clinical effect of reporting them has not been sufficiently investigated. In addition, professional societies express their need for data assessing the clinical use of genome-wide noninvasive prenatal testing for rare autosomal trisomies for years. OBJECTIVE: This study aimed to investigate the origin of rare autosomal trisomies and the clinical effect of disclosing rare autosomal trisomies in clinical settings. STUDY DESIGN: Women who received noninvasive prenatal testing between March 2021 and March 2022 were prospectively enrolled. Clinical follow-up and cytogenetic and molecular investigations were performed. Posthoc analysis was performed to investigate the association between placental mosaicism and clinical outcomes. RESULTS: Overall, 154 rare autosomal trisomies were identified in 89,242 pregnancies (0.17%) through noninvasive prenatal testing. In the 120 cases in which cytogenetic and molecular investigations were carried out, the rare autosomal trisomies were found to originate from true fetal mosaicism (n=5), uniparental disomy (n=5), maternal mosaic trisomy (n=3), maternal malignancy (n=1), and confined placental mosaicism (n=106). Clinical follow-up showed that 40% of all rare autosomal trisomy cases had adverse perinatal outcomes. In women with false-positive noninvasive prenatal testing results originating from confined placental mosaicism, the frequency of adverse perinatal outcomes was 26%. More importantly, the placental mosaicism ratio revealed by noninvasive prenatal testing was significantly higher in women who experienced adverse perinatal outcomes than those who did not (0.688 vs 0.332; P<.001). CONCLUSION: Women with noninvasive prenatal testing results indicative of rare autosomal trisomies are at risk of adverse perinatal outcomes, and that risk can be stratified using chromosomes and the mosaicism ratio revealed by noninvasive prenatal testing. Our data are valuable for obstetrical caregivers advising a patient with a noninvasive prenatal testing result indicative of a rare autosomal trisomy and a false-positive diagnosis and for managing risks during pregnancy.

Prenatal Silver-Russell Syndrome in a Chinese Family Identified by Non-Invasive Prenatal Testing.

Russell-Silver syndrome (SRS) is a rare condition characterized by poor growth before and after birth along with multiple physical and psychosocial characteristics such as short stature, characteristic facial features, body asymmetry, feeding difficulties, and learning disabilities. In this study, we report a family with 2 recurrent SRS pregnancies due to a derivative chromosome 15 that is the result of a maternally derived t(11;15) translocation, detected by non-invasive prenatal testing (NIPT). The 2 SRS fetuses were diagnosed by chromosomal microarray analysis, but a balanced, reciprocal translocation of the mother was disclosed by the combination of routine karyotyping and FISH. This study demonstrates that NIPT has the ability to identify submicroscopic copy number variations (CNVs) in fetuses, which in some cases may result from a parent being a balanced rearrangement carrier. Because of the differences in resolution and the various benefits and limitations of each genetic technique, great care must be taken when deciding on which test(s) to employ in family studies.

Detection of rare thalassemia mutations using long-read single-molecule real-time sequencing.

Gap- polymerase chain reaction (PCR), reverse dot-blot assay (RDB), real-time PCR based multicolor melting curve analysis (MMCA assay), multiplex ligation-dependent probe amplification (MLPA) and Sanger sequencing are conventional methods to diagnose thalassemia but all of them have limitations. In this study, we applied single-molecule real-time (SMRT) sequencing following multiplex long-range PCR to uncover rare mutations in nine patients and their family members. The patients with different results between Gap-PCR and MMCA assay or with phenotype not matching genotype were included. Using SMRT sequencing, we first identified the carriers with αααanti3.7/HKαα, -α762bpα/αα (chr16:172,648-173,409), ααfusion/αQSα (in a trans configuration), two cases with novel gene rearrangements and another case with a novel 341 bp insertion in α-globin gene cluster, respectively. One carrier with --SEA/αααanti4.2, and two carriers with the coexistence of globin variant and an α-globin gene duplication were also found. Most importantly, we could determine two defects in α-globin gene cluster being a cis or trans configuration in a single test. Our results showed that SMRT has great advantages in detection of α-globin gene triplications, rare deletions and determination of a cis or trans configuration. SMRT is a comprehensive and one-step method for thalassemia screening and diagnosis, especially for detection of rare thalassemia mutations.

Contribution of maternal mosaicism to false-positive chromosome X loss associated with noninvasive prenatal testing.

OBJECTIVE: To report the frequency of maternal mosaicism contributing to false-positive chromosome X loss associated with noninvasive prenatal testing (NIPT) at a single center. METHODS: Pregnancies undergone NIPT using massively parallel sequencing at Guangzhou Women and Children's Medical Center between February 2015 and May 2020 were included in this study. Fetal karyotyping, quantitative fluorescence PCR (QF-PCR) or microarray analysis was provided to patients with abnormal sex chromosomal aneuploidy (SCA) results for confirmatory testing, and QF-PCR was also employed to detect maternal sex chromosome status. RESULTS: cffDNA testing of 40682 pregnancies revealed 86 cases with NIPT results positive for chromosome X loss (0.21%). Among the 86 high-risk cases, 73 women had undergone confirmatory testing in our center, whereas 13 declined. Of the 73 women verified by invasive prenatal diagnosis, 27.4% (20/73) were true positive cases including six cases of monosomy X, two cases of microdeletion of Xp22.33, one case of deletion Xq27.2q28, one case of 47, XXX and ten cases with fetal sex chromosome mosaicism. Of the remaining 53 patients with fetal normal results, 30 cases had undergone QF-PCR analysis of maternal white blood cells. QF-PCR indicated that 36.7% (11/30) patients had an altered or mosaic maternal sex chromosome status. Statistical analysis indicated that cell-free fetal DNA (cffDNA) concentration estimated by chromosome X in maternal mosaic cases was significantly higher than that in the non-maternal mosaicism group (p < .05) and was related to maternal mosaicism rate (r = 0.88, p < .05). CONCLUSIONS: Our findings indicated that maternal mosaicism of sex chromosome was not uncommon in false-positive NIPT chromosome X loss cases. We recommend that this information should be disclosed to pregnancies during clinical counseling and maternal sex chromosome status should be confirmed for the cases with NIPT chromosome X loss.

A novel splicing mutation of ARHGAP29 is associated with nonsyndromic cleft lip with or without cleft palate.

BACKGROUND: Nonsyndromic cleft lip with or without cleft palate (NSCL/P) is one of the most common birth defects, and occurs in approximately 1/700 live births worldwide. The correlation between the ABCA4-ARHGAP29 region and NSCL/P was first identified by genome-wide association studies (GWAS), but few reports have examined NSCL/P caused by ARHGAP29 mutations in the Chinese population. METHODS: We performed chromosome microarray analysis (CMA) for two consecutive abnormal fetuses and whole exome sequencing (WES) for the family, including 3 patients and 2 normal family members, Sanger sequencing and RT-PCR were used to confirm the mutation. RESULTS: We identified a novel splice donor mutation (ARHGAP29 c.1920 + 1G > A) in two consecutive NSCL/P fetuses, and the variant was inherited from the mother and grandfather. The mutation caused abnormal skipping of exon 17, and the mRNA level of ARHGAP29 was significantly decreased compared to the wild type. CONCLUSIONS: In this study, we successfully diagnosed the genetic cause of NSCL/P in a family and first report that the c.1920 + 1G > A mutation in ARHGAP29 is associated with NSCL/P. Our study enriches the genetic landscape of NSCL/P, extends the mutation spectrum of ARHGAP29, and provides a new direction for the diagnosis of NSCL/P in patients and its prenatal diagnosis in fetuses.

Tumor-Infiltrating CD8+ T Cells Driven by the Immune Checkpoint-Associated Gene IDO1 Are Associated With Cervical Cancer Prognosis.

Tumor-infiltrating immune cells, associated with tumor progression, are promising prognostic biomarkers. However, the relationship between levels of gene expression and that of immune cell infiltration in cervical cancer prognosis is unknown. In this study, three cervical cancer gene expression microarrays (GSE6791, GSE63678 and GSE55940) were obtained from the GEO database. The IDO1 gene was identified by differentially expressed gene screening. The gene expression profiles of TCGA and GTEx databases along with comprehensive bioinformatics analysis identified that the IDO1 gene was upregulated in cervical cancer with significant difference in expression at different N stages. In addition, it was also upregulated in HPV16 positive sample. The pan-cancer analysis identified that IDO1 was highly expressed in most cancers. TIMER analysis revealed that the expression of IDO1 in CESC shows positive correlation with CD8+ T cells, CD4+ T cells, neutrophils, dendritic cells. IDO1 expression showed remarkable positive correlation with all immune cell markers except M1 macrophages. CD8+ T cell infiltration GSEA results showed that IDO1 was mainly associated with tumor immune-related signaling pathways.

Uterine necrosis, infection, and subinvolution: complications observed after combined application of modified B-Lynch suture and vascular ligation.

Compression sutures are primarily used to treat atonic postpartum hemorrhage. We herein describe three cases of selective arterial ligation combined with B-Lynch or modified B-Lynch suture for the treatment of intractable postpartum hemorrhage unresponsive to available conservative interventions. Three pregnant women underwent a cesarean section for a macrosomic fetus, fetal distress, and oligohydramnios, respectively. All three women developed intractable postpartum hemorrhage due to uterine atony with no chance of embolization therapy. B-Lynch or modified B-Lynch suture and additional selective arterial ligation were performed using braided absorbable suture. The first woman developed postoperative hematometra and infection without response to drainage and antibiotic therapy. Although laparoscopic exploration was performed to loosen the suture line and drain the hematometra and pyometra, the necrosis and infection could not be controlled. Subtotal hysterectomy was therefore conducted, and the necrotic uterine adnexa was removed. The other two women developed subinvolution of the uterus resulting in prolonged menstruation and amenorrhea, although the uterus was preserved and the bleeding was controlled. Modified B-Lynch suture combined with vascular ligation is an invaluable technique for women with severe intractable postpartum hemorrhage. However, it can lead to serious complications such as uterine necrosis, infection, and subinvolution.

Noninvasive prenatal testing of α-thalassemia and ß-thalassemia through population-based parental haplotyping.

BACKGROUND: Noninvasive prenatal testing (NIPT) of recessive monogenic diseases depends heavily on knowing the correct parental haplotypes. However, the currently used family-based haplotyping method requires pedigrees, and molecular haplotyping is highly challenging due to its high cost, long turnaround time, and complexity. Here, we proposed a new two-step approach, population-based haplotyping-NIPT (PBH-NIPT), using α-thalassemia and ß-thalassemia as prototypes. METHODS: First, we deduced parental haplotypes with Beagle 4.0 with training on a large retrospective carrier screening dataset (4356 thalassemia carrier screening-positive cases). Second, we inferred fetal haplotypes using a parental haplotype-assisted hidden Markov model (HMM) and the Viterbi algorithm. RESULTS: With this approach, we enrolled 59 couples at risk of having a fetus with thalassemia and successfully inferred 94.1% (111/118) of fetal alleles. We confirmed these alleles by invasive prenatal diagnosis, with 99.1% (110/111) accuracy (95% CI, 95.1-100%). CONCLUSIONS: These results demonstrate that PBH-NIPT is a sensitive, fast, and inexpensive strategy for NIPT of thalassemia.

miR-613 inhibits the proliferation of human ovarian granulosa cells by arresting cell cycle progression via the targeting of IGF-1.

Polycystic ovary syndrome (PCOS) is a prevalent endocrine disorder, and microRNA (miRNA) molecules have been implicated in the pathological process of PCOS. The aim of the present study was to elucidate the regulatory effects of miR-613 and insulin-like growth factor-1 (IGF-1) on the pathological process of polycystic ovary syndrome (PCOS). The targeting of IGF-1 by miR-613 was investigated by dual-luciferase reporter assay. The regulatory effect of miR-613 on the mRNA and protein levels of IGF1 was determined by reverse transcription-quantitative PCR and western blot analysis. The regulatory effects of miR-613 and IGF-1 on the proliferation and cell cycle progression of KGN cells were evaluated by colony formation assay and flow cytometric analysis. The results revealed that miR-613 targeted IGF-1 and reduced its translational level. In KGN cells, miR-613 arrested cell cycle progression in the G2/M phase and downregulated the expression of cyclin D1 and CDK1. The overexpression of IGF-1 attenuated the inhibitory effects of miR-613 on cell cycle arrest, cyclin D1 and CDK1 expression, and the proliferation of KGN cells. In conclusion, the present study demonstrated that miR-613 targets IGF-1 and thus suppresses its translation. It arrests cell cycle progression and attenuates the proliferation of KGN cells via the targeting of IGF-1. Therefore, it is suggested that miR-613 and IGF-1 could potentially be diagnostic biomarkers and therapeutic targets for PCOS.

Research Progress of HIV-1 Nef Inhibitors.

HIV-1 infection poses a major threat to the public health worldwide. The antiretroviral agents that are currently used to treat HIV-1 infection target viral reverse transcriptase, integrase and protease, or block the fusion of viral envelop and cell membrane. Studies have shown that the HIV-1 encoded protein Nef plays an important role in the pathogenesis of viral infection. Nef ensures efficient counterattack against host immune responses as well as long-term evasion of immune surveillance. In addition, Nef, expressing at a high level early in the viral life cycle, is required for maintaining a high viral load in the persistent infection in vivo and for full pathologic potential. Therefore, Nef may be an excellent target to treat HIV-1 infection. In this manuscript, we reviewed five potential Nef inhibitors, namely, DLC27-14, t ightly bound hydroxypyrazole HIV-1 Nef inhibitor B9, 2c-like inhibitors, N-(3-aminoquinoxalin-2-yl)-4-chlorobenzenesulfonamide and compound 1[(7-oxo-7H-benzo[anthracene]-3-yl)amino]anthraquinone, and their working mechanisms. These drugs may be further developed into new regimens for the treatment of HIV-1 infection.

Rosiglitazone ameliorates palmitic acid-induced endoplasmic reticulum stress and steroidogenic capacity in granulosa cells.

Granulosa cells play essential roles in follicular development, oocyte maturation and sex hormone secretion. The exposure of granulosa cells to palmitic acid (PA), the main component of dietary saturated fat, inhibits cell viability. However, the mechanism underlying PA-induced cytotoxicity in granulosa cells has not been deeply investigated. Rosiglitazone (RSG) is a member of the thiazolidinedione family and is reported to protect cells from cytotoxicity and endoplasmic reticulum (ER) stress in other cell types, but whether RSG protects granulosa cells remain unknown. In this study, KGN cell line and primary granulosa cells were used as models of granulosa cells to explore the effects of PA and RSG and the underlying mechanisms. The results showed that PA inhibits cell viability and estradiol secretion through inducing ER stress and cAMP/PKA/CREB pathway. CCAAT/enhancer-binding protein homologous protein (CHOP), an ER stress marker, was demonstrated to participate in PA-induced cytotoxicity. RSG treatment rescued granulosa cells from PA-induced cell death and ER stress. Moreover, RSG was identified to ameliorate ER stress induced by tunicamycin in granulosa cells. In addition, RSG treatment rescued granulosa cells from PA-induced decrease of estrogen secretion by cAMP/PKA/CREB pathway. In conclusion, RSG can protect granulosa cells against PA-induced cytotoxicity by inhibiting ER stress, and can recover steroidogenic capacity, indicating a potential use of RSG in the treatment of granulosa cell dysfunction.

Use of noninvasive prenatal screening with cell-free DNA in late pregnancy with sonographic soft markers.

OBJECTIVE: To report the experience on the clinical use of noninvasive cell-free (cf) DNA testing at late pregnancy. STUDY DESIGN: A cohort of 1539 women with singleton gestations of ≥23 weeks receiving cfDNA testing in a 3-year period were included for this study. Maternal characteristics and data on cfDNA testing, confirming diagnostic testing and pregnancy outcome were reviewed. RESULTS: During the study period, 1539 patients had cfDNA testing although they had a normal first-trimester screening. Of these, 7 cases had a positive result, including 5 for chromosome 21, one for chromosome 18, and one for chromosome 13. The most common indication was soft markers on ultrasound, followed by polyhydramnios. Cytogenetic testing was done for the 5 trisomy 21 positive cases, and confirmed the cfDNA results. Confirmative testing was declined in the two cases with positive cfDNA for trisomy 18/13, and postnatal placental investigation showed confined placental mosaicism with normal karyotype in the cord blood of newborns. There were no confirmed false negatives reported. The cfDNA screening achieved a positive predictive value of 71.4 % and a negative predictive value of 100 % in late pregnancy for common trisomies. CONCLUSIONS: There is no gestational age upper limit for cfDNA use in the clinical practice. Most of the time, cfDNA was used in late gestation for reassurance in patients who is at low risk for aneuploidies but had second-trimester soft markers on ultrasound.

Long Non-Coding RNA HULC Promotes Cervical Cancer Cell Proliferation, Migration and Invasion via miR-218/TPD52 Axis.

OBJECTIVE: Long non-coding RNAs (lncRNAs) have been identified as important players in tumorigenesis. LncRNA highly upregulated in liver cancer (HULC) has been identified as a key regulator in the progression of various cancers. However, the functional role and the mechanisms of HULC in regulating cervical cancer cell behavior remain unclear. METHODS: HULC expression, miR-218 expression and TPD52 mRNA level in cervical cancer cells were examined by qRT-PCR. Cell proliferation was evaluated by MTT assay. Cell migration and invasion were examined by Transwell assay. TPD52 protein level was measured by Western blot. Dual-luciferase reporter assay was measured to verify the combination of HULC and miR-218 as well as miR-218 and TPD52. RESULTS: HULC expression was upregulated in cervical cancer cell lines, and HULC promoted cervical cancer cell proliferation, migration and invasion. Mechanistically, HULC acted as a sponge of miR-218 to elevate expression of TPD52, a target of miR-218, and thereby promoted cervical cancer cell proliferation, migration, and invasion. CONCLUSION: HULC promotes cervical cancer cell proliferation, migration and invasion via miR-218/TPD52 axis.

Hypoxia-induced PLOD2 regulates invasion and epithelial-mesenchymal transition in endometrial carcinoma cells.

BACKGROUND: Procollagen-lysine, 2-oxoglutarate 5-dioxygenase 2 (PLOD2) was induced in hypoxia and participated in cancer development. However, the role of PLOD2 in endometrial carcinoma remains unclear. OBJECTIVE: To explore the influences and regulation mechanism of PLOD2 in endometrial carcinoma under hypoxic condition. METHODS: The small interfering RNA (siRNA) targeting to PLOD2 and pcDNA3.1-PLPD2 were transfected to endometrial carcinoma cells to alter PLOD2 expression. Cell proliferation ability was determined by colony formation assay. Wound healing assay used to detect cell migration ability. Transwell invasion assay was used to detect cell invasion ability. RESULTS: PLOD2 and Hypoxia-inducible factor-1α (HIF-1α) were induced by hypoxia. Down-regulation of PLOD2 did not affect endometrial carcinoma cell proliferation ability, while inhibited cell migration, invasion under hypoxic condition. Besides, down-regulation of PLOD2 increased the levels of γ-catenin and E-cadherin and decreased levels of Fibronectin and Snail under hypoxic condition. Down-regulation of PLOD2 also inactivated Src and phosphoinositide 3-kinase (PI3K)/ protein kinase B (Akt) signaling under hypoxic condition. The promoting effects of PLOD2 overexpression on migration, invasion and epithelial-mesenchymal transition (EMT) of endometrial carcinoma cells were reversed by Akt inhibitor (MK2206) under hypoxic condition. CONCLUSION: PLOD2 expression was increased in endometrial carcinoma cells under hypoxic condition. PLOD2 modulated migration, invasion, and EMT of endometrial carcinoma cells via PI3K/Akt signaling. PLOD2 may be a potential therapeutic target for endometrial carcinoma.

A retrospective analysis of the treatment on abdominal aortic balloon occlusion-related thrombosis by continuous low-flow diluted heparin.

Thrombosis is one of the serious complications related to prophylactic balloon occlusion of the abdominal aorta (PBOAA). This study aims to retrospectively analyze the efficacy and safety of continuous low-flow infusion of diluted heparin saline to prevent this complication related to PBOAA and further to provide the theory and evidences for using PBOAA.A study was carried out at our hospital from March 2016 to December 2018. Women with pernicious placenta previa (PPP) were treated PBOAA to prevent massive bleeding during CS. According to whether continuous low-flow infusion of diluted heparin saline was used to prevent catheter-related thrombosis or not, they were divided into 2 groups, the test group and the control group. The incidence of thrombosis between the 2 groups was compared and the effective treatment of thrombosis was also discussed. The comparison of nonparametric values was accomplished by using Fisher exact test. Statistical significance was set at P < .05.There were 31 women with PPP who received PBOAA during CS who were included in our study. Six of 19 women in control group (31.6%) developed thrombotic complications, while none of 12 women in test group. There were statistically significant differences in the incidence of thrombosis between the 2 groups (P = .037). There was no statistically significant difference in the amount of estimated blood loss and blood transfusion during CS between the 2 groups, nor was there statistically significant difference in the hospital days after CS (P > .05). All 6 women with thrombotic complications had no positive symptoms and thrombotic sequelae. The managements of thrombus included systemic anticoagulation, catheter-directed thrombolysis, and catheter-directed anticoagulation. One of the 6 women was lost to follow-up, and the thrombus of the other 5 women were completely dissolved. No other adverse outcomes or complications related to PBOAA were observed in all women in this study.Continuous low-flow infusion of diluted heparin saline is a safe procedure when PBOAA is performed for patients with PPP. It can effectively reduce or even avoid thrombosis without increasing intraoperative blood loss during CS for PPP patients.