Secondary cesarean delivery postpartum hemorrhage risk early warning model
By constructing a risk warning model for postpartum hemorrhage after a second cesarean section based on logistic regression analysis, the problem of lack of specific assessment tools in existing technologies was solved, and accurate prediction and stratified management of the risk of postpartum hemorrhage after a second cesarean section were achieved, thereby reducing the incidence of severe postpartum hemorrhage.
Patent Information
- Application Number
- CN202510798638.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-16
- Publication Date
- 2025-09-26
AI Technical Summary
Existing technologies lack specific postpartum hemorrhage risk assessment tools for secondary cesarean sections. Traditional models do not incorporate key factors, have insufficient predictive performance, lack stratified management, are complex and difficult to promote quickly, have low clinical practicality, and lack effective early warning measures to identify high-risk groups.
A risk warning model for postpartum hemorrhage after secondary cesarean section was constructed based on logistic regression analysis. Risk factors were screened through data collection, univariate and multivariate analysis, and a nomogram model was established. Factor scores were assigned and the total score was calculated as the risk warning value. Risk assessment and intervention recommendations were made in combination with the risk warning system and medical equipment.
It improves the prediction accuracy and stratified management capabilities of the risk of postpartum hemorrhage after secondary cesarean section, simplifies the risk assessment process, supports the rapid identification of high-risk groups and provides personalized intervention measures, and reduces the incidence of severe postpartum hemorrhage.
Smart Images
Figure CN120708892A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of obstetrics and gynecology medical technology, and in particular to a risk warning model for postpartum hemorrhage after secondary cesarean section. Background Art
[0002] Postpartum hemorrhage is one of the most serious complications of childbirth and the leading cause of maternal mortality. With the increase in cesarean section rates, the risk of severe postpartum hemorrhage after a second cesarean section has increased significantly. Due to complex factors such as uterine scar formation, placental adhesion or implantation, the difficulty of surgery and the risk of bleeding in a second cesarean section are much higher than those in a first cesarean section. Currently, clinical predictions of postpartum hemorrhage are mostly based on a single indicator (such as antenatal hemoglobin level, previous bleeding history), or a general risk scoring model, and there is a lack of specific assessment tools for second cesarean sections. Although existing studies have attempted to construct prediction models, most of them have the following deficiencies:
[0003] Limited predictive performance: Traditional models (such as antenatal scoring scales) do not incorporate key factors such as placental status and history of uterine surgery, resulting in insufficient sensitivity and specificity;
[0004] Lack of tiered management: Risk quantification and grading are not achieved, making it difficult to guide personalized interventions;
[0005] Not focusing on secondary cesarean sections: Most studies focus on primary cesarean sections or vaginal deliveries, ignoring the specific risks of secondary surgeries (such as placental abnormalities and myometrial damage);
[0006] Low clinical practicality: The model is highly complex or relies on laboratory testing, making it difficult to promote quickly.
[0007] Furthermore, severe postpartum hemorrhage often requires blood transfusion, hysterectomy, and can be life-threatening, but there is a lack of effective early warning methods to identify high-risk groups. Therefore, developing a risk warning model specifically for secondary cesarean sections that integrates multiple clinical factors and is easy to use is of great significance for improving perioperative management and reducing postpartum hemorrhage-related mortality. Summary of the Invention
[0008] The purpose of the present invention is to solve the shortcomings of the existing technology and propose a risk warning model for postpartum hemorrhage after secondary cesarean section.
[0009] In order to achieve the above object, the present invention adopts the following technical solutions:
[0010] A method for constructing a risk warning model for postpartum hemorrhage after a second cesarean section, comprising the following steps:
[0011] Data collection: Clinical data of women undergoing secondary cesarean section were collected, including basic and historical information, information on the current pregnancy period, information on the current pregnancy and delivery period, and outcome variables;
[0012] Univariate analysis: screening for significant factors including assisted reproductive technology, pre-pregnancy body mass index, prenatal body mass index, gravidity, number of previous cesarean sections, number of fetuses, gestational age at termination of pregnancy, hypertension, uterine fibroids, placenta-uterine relationship, fetal presentation, and uterine height;
[0013] Multivariate analysis: Logistic regression analysis was used to identify independent risk factors, including gestational age at termination of pregnancy, concomitant uterine fibroids, and the relationship between the placenta and uterus.
[0014] Model construction: A nomogram model was established based on the above risk factors, and scores were assigned to each factor;
[0015] Risk calculation: Add up the scores of each factor, and the total score corresponds to the probability of postpartum hemorrhage, which serves as the risk warning value.
[0016] Preferably, the nomogram model is implemented by R software, and the risk prediction value is calculated using the following formula:
[0017]
[0018] Among them, X1, X2, …, X n is each risk factor, α is the intercept, and β is the regression coefficient.
[0019] Preferably, postpartum hemorrhage is defined as intra-cesarean section bleeding volume ≥1000 ml within 24 hours after delivery of the fetus, or blood loss accompanied by symptoms / signs of hypovolemia; severe postpartum hemorrhage is defined as bleeding volume ≥1000 ml and requiring surgical intervention or blood transfusion.
[0020] Preferably, the relationship between the placenta and the uterus includes placenta accreta, placenta accreta and placenta percreta, which are assigned different scores respectively; ROC curve analysis is used for model verification.
[0021] A risk warning system based on a risk warning model for postpartum hemorrhage after secondary cesarean section: the risk warning system comprises:
[0022] Data collection module: input maternal clinical data and automatically match model risk factors;
[0023] Risk assessment module: calculates the total score and bleeding risk probability based on the nomogram model;
[0024] Early warning output module: generates visual risk level reports;
[0025] Intervention recommendation module: Automatically push intervention plans for high-risk groups, including preoperative blood preparation, intraoperative hemostasis measures and postoperative monitoring strategies.
[0026] Preferably, the data acquisition module is integrated with a hospital information system interface to support real-time retrieval of electronic medical record data.
[0027] Preferably, the intervention suggestion module includes a hierarchical management strategy:
[0028] Low risk: routine monitoring;
[0029] Medium risk: Strengthen intraoperative hemostasis preparation;
[0030] High risk: Initiate a multidisciplinary collaborative diagnosis and treatment process.
[0031] Preferably: the risk warning system further includes a data encryption module.
[0032] A computer-readable storage medium based on a risk warning model for postpartum hemorrhage after a second cesarean section, wherein the medium stores a computer program that, when executed, implements the following functions:
[0033] Receive clinical data of women who underwent second cesarean section;
[0034] Call the nomogram model to calculate the risk score;
[0035] Output risk warning results and visualization reports.
[0036] A medical device for a risk warning model of postpartum hemorrhage after a second cesarean section: the medical device comprises:
[0037] A processor for running a risk warning model algorithm;
[0038] A display screen for displaying risk assessment results and intervention recommendations;
[0039] Input device, used to enter maternal clinical data or connect external equipment.
[0040] The beneficial effects of the present invention are:
[0041] 1. Based on large-sample data and logistic regression analysis, this paper screened out three independent risk factors for termination of pregnancy: gestational age, combined uterine fibroids, and the relationship between the placenta and uterus. The model construction was statistically significant. The nomogram design quantified the risk score, converted abstract risks into visual numerical values, and improved clinical decision-making efficiency.
[0042] 2. The area under the ROC curve of the present invention reached 0.783 (95% CI: 0.732-0.834), indicating that the model has excellent ability to distinguish high-risk from low-risk populations; the slope of the calibration curve is close to 1, and the Hosmer-Lemeshow test confirms that the predicted value is consistent with the actual observation, ensuring the accuracy of risk assessment.
[0043] 3. This invention focuses on the risk of postoperative bleeding after a second cesarean section, breaking through the limitations of the traditional model for first surgery or vaginal delivery; it guides stratified management through risk stratification, such as preoperative blood preparation for high-risk patients and strengthening hemostasis measures during surgery, thereby reducing the hysterectomy rate.
[0044] 4. The present invention only requires routine clinical indicators and no additional testing is required; the nomogram is intuitive and easy to read, and supports quick calculations. For example, a total score ≥ 60 points indicates a high risk, which facilitates rapid preoperative assessment by the surgeon. BRIEF DESCRIPTION OF THE DRAWINGS
[0045] Figure 1 This is a nomogram model for the risk of severe postpartum hemorrhage during secondary cesarean section according to the present invention;
[0046] Figure 2 This is the ROC curve diagram of the prediction model of the present invention;
[0047] Figure 3 It is a calibration curve diagram of the nomogram model of the present invention. DETAILED DESCRIPTION
[0048] The technical solution of the present invention will be further described in detail below in conjunction with specific implementation methods.
[0049] Example 1:
[0050] A risk warning model for postpartum hemorrhage after secondary cesarean section
[0051] 1. Methods
[0052] 1.1 General data A total of 646 pregnant women who underwent a second cesarean section and were hospitalized in the Department of Obstetrics and Gynecology of Chongqing Southeast Hospital and Chongqing People's Hospital from January 2022 to March 2024 were selected as the research subjects. According to the amount of postpartum hemorrhage at the time of termination of pregnancy, they were divided into two groups: ① second cesarean section bleeding <1000ml group (no bleeding group); ② second cesarean section bleeding ≥1000ml (severe postpartum hemorrhage group).
[0053] 1.2 Inclusion criteria (1) Inclusion criteria: ① Previous cesarean section delivery; ② Indications for cesarean section or voluntary choice of cesarean section at this time; ③ The mother and her family are aware of the mode of delivery and have signed a consent form. (2) Exclusion criteria: ① Patients who have undergone two or more cesarean sections and are pregnant again; ② Patients with incomplete clinical data; ③ Patients with severe liver disease or blood system disease, including hemophilia, that affects the patient's coagulation function; ④ Patients with obvious bleeding tendency due to tumor diseases (such as hematopoietic system dysfunction, etc.).
[0054] 1.3 Case information collection content
[0055] A research team was established to determine the research plan and specific implementation steps. Before data collection, two medical staff with at least five years of experience in obstetrics and gynecology were selected for professional training and briefed on the study objectives and methods. Collected patient information included basic and historical information, information about the current pregnancy, and information about the current delivery period. The outcome variable was postpartum hemorrhage volume.
[0056] Specifically, they include age, marital history, assisted reproduction, pre-pregnancy weight index, number of pregnancies, history of miscarriage, history of uterine surgery, number of fetuses, gestational age at termination, number of prenatal examinations, amniotic fluid index, placental attachment site, placental ultrasound manifestations, relationship between the placenta and uterus, placental separation, combined uterine fibroids, combined anemia, combined thrombocytopenia, combined hypertension, combined diabetes and many other factors.
[0057] 1.4 Definition and assessment criteria of postpartum hemorrhage
[0058] 1.4.1 Definition of postpartum hemorrhage and severe postpartum hemorrhage
[0059] Postpartum hemorrhage (PPH) refers to maternal blood loss of ≥500ml for vaginal delivery, ≥1000ml for cesarean section, or blood loss accompanied by symptoms or signs of hypovolemia within 24 hours after delivery. Currently, many countries and studies around the world consider blood loss ≥1000ml within 24 hours postpartum to be severe. Furthermore, clinically, severe PPH that cannot be stopped with conservative measures such as uterotonics, continuous uterine massage or pressure, and requires surgery, interventional therapy, or even hysterectomy, is often referred to as refractory PPH.
[0060] 1.4.2.2 Postpartum hemorrhage assessment criteria
[0061] ① During the procedure, the amniotic fluid is aspirated and recorded from amniotic membrane puncture until placental separation. The blood volume in the negative pressure bottle is calculated by subtracting the amniotic fluid volume. ② The blood volume on the gauze and gauze pad is measured by weighing. ③ Upon transfer to the ward, the 24-hour blood loss is calculated by weighing medical nursing pants that can assess blood loss. The sum of these three items is the postpartum blood loss.
[0062] 1.5 Methods
[0063] 1.5.1 Statistical methods SPSS 24.0 software was used to analyze the data. Measurement data were expressed as x ± s. Independent sample t-test was used between groups, and paired sample t-test was used within groups. Enumeration data were expressed as percentages and the χ2 test was used. P < 0.05 was considered statistically significant.
[0064] 2 Results
[0065] A total of 646 women were included in the study, of whom 445 experienced no bleeding after a second cesarean section, while 201 experienced severe postpartum hemorrhage (an incidence rate of 42.76%). No women experienced hemorrhagic shock or hysterectomy, and no women died from hemorrhage.
[0066] 2.1 Univariate analysis of factors influencing severe postpartum hemorrhage during secondary cesarean section
[0067] The results of univariate analysis showed that 13 factors, including assisted reproductive technology, pre-pregnancy body mass index, prenatal body mass index, number of gravidities, number of previous cesarean sections, number of fetuses, gestational age at termination of pregnancy, combined hypertension, combined uterine fibroids, relationship between placenta and uterus, fetal presenting part, and uterine height, were the main factors affecting postpartum hemorrhage after secondary cesarean section (P<0.05).
[0068] 2.2 Multifactorial analysis of factors affecting severe postpartum hemorrhage during secondary cesarean section
[0069] The significant variables in univariate analysis were used as independent variables and postpartum hemorrhage as dependent variables.
[0070] Logistic regression analysis showed that gestational age at termination of pregnancy, combined uterine fibroids, and the relationship between the placenta and uterus were risk factors for postpartum hemorrhage after secondary cesarean section (P<0.05).
[0071] 2.3 Establishment of a nomogram model for predicting severe postpartum hemorrhage after secondary cesarean section
[0072] The main influencing factors of postpartum hemorrhage after cesarean section were analyzed based on the logistic regression model, and the nomogram model was established using R software ( Figure 1 The predicted probability corresponding to the sum of the scores for each indicator is the predicted risk of postpartum hemorrhage. A gestational age of <37 weeks is scored as 32.5 points, combined with uterine fibroids as 29 points, placenta accreta as 32 points, and placenta accreta as 100 points.
[0073] 2.3 Validation of the nomogram model for severe postpartum hemorrhage after secondary cesarean section
[0074] The risk prediction value of postpartum hemorrhage after secondary cesarean section was calculated according to the prediction model formula, and the area under the ROC curve was used to evaluate the nomogram, and the area under the curve was 0.783 (95% CI: 0.732-0.834). Figure 2 , which indicates that the nomogram model has good discrimination ability. The slope of the calibration curve is close to 1, as shown in Figure 3 As shown in the results, the Hosmer-Lemeshow goodness-of-fit test showed that the nomogram model had good consistency in predicting the risk of postpartum hemorrhage after secondary cesarean section.
[0075] 3 Discussions
[0076] Postpartum hemorrhage (PPH) is one of the more urgent conditions that can occur during childbirth. Characterized by clinical manifestations such as vaginal bleeding and secondary anemia, it can seriously threaten maternal safety. Therefore, risk prediction for PPH is crucial. Severe PPH is particularly prevalent after a second cesarean section, as the surgical difficulty and complexity increase, and excessive bleeding can lead to maternal mortality. Therefore, investigating the risk factors for severe PPH after a second cesarean section is crucial for improving maternal surgical safety. Various methods have demonstrated the feasibility of constructing PPH prediction models; however, predictive performance remains unsatisfactory, particularly for severe PPH after a second cesarean section. Studies have shown that nomograms, with their unique advantages of intuitiveness and specificity, have been widely used in recent years for risk prediction of adverse clinical events. This study, using logistic regression analysis of the clinical data of women undergoing a second cesarean section, found that 13 factors, including assisted reproductive technology, pre-pregnancy body mass index (BMI), prenatal BMI, gravidity, number of previous cesarean sections, number of fetuses, gestational age at termination, hypertension, uterine fibroids, placental-uterine relationship, fetal presentation, and uterine height, were the primary factors influencing severe postpartum hemorrhage after a second cesarean section. A nomogram model was developed based on these factors to predict postpartum hemorrhage after a second cesarean section. This model provides a valuable reference for clinical analysis of various factors influencing the risk of severe postpartum hemorrhage in women undergoing a second cesarean section, helping to identify high-risk women and implement effective measures to reduce the incidence of severe postpartum hemorrhage after a second cesarean section.
[0077] In summary, the nomogram predictive model for severe postpartum hemorrhage in women undergoing a second cesarean section, constructed using risk factor statistics, demonstrates good discrimination and consistency. It addresses the clinical challenges of effectively and accurately identifying this high-risk population, initiating preventive interventions, and actively referring patients for standardized diagnosis and treatment. This model provides a preoperative warning for severe hemorrhage in subsequent pregnancies after cesarean section.
[0078] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.
Claims
1. A risk warning model for postpartum hemorrhage after secondary cesarean section, characterized by: The method for constructing the early warning model comprises the following steps: Data collection: Clinical data of women undergoing secondary cesarean section were collected, including basic and historical information, information on the current pregnancy period, information on the current pregnancy and delivery period, and outcome variables; Univariate analysis: screening for significant factors including assisted reproductive technology, pre-pregnancy body mass index, prenatal body mass index, gravidity, number of previous cesarean sections, number of fetuses, gestational age at termination of pregnancy, hypertension, uterine fibroids, placenta-uterine relationship, fetal presentation, and uterine height; Multivariate analysis: Logistic regression analysis was used to identify independent risk factors, including gestational age at termination of pregnancy, concomitant uterine fibroids, and the relationship between the placenta and uterus. Model construction: A nomogram model was established based on the above risk factors, and scores were assigned to each factor; Risk calculation: Add up the scores of each factor, and the total score corresponds to the probability of postpartum hemorrhage, which serves as the risk warning value.
2. A postpartum hemorrhage risk warning model for secondary cesarean section according to claim 1, characterized in that: The nomogram model was implemented using R software, and the risk prediction value was calculated using the following formula: Among them, X1, X2, …, X n is each risk factor, α is the intercept, and β is the regression coefficient.
3. A risk warning model for postpartum hemorrhage after secondary cesarean section according to claim 2, characterized in that: Postpartum hemorrhage is defined as bleeding volume ≥1000 ml during cesarean section within 24 hours after delivery of the fetus, or blood loss accompanied by symptoms / signs of hypovolemia; severe postpartum hemorrhage is defined as bleeding volume ≥1000 ml and requiring surgical intervention or blood transfusion.
4. A risk warning model for postpartum hemorrhage after secondary cesarean section according to claim 3, characterized in that: The relationship between the placenta and the uterus includes placenta accreta, placenta accreta and placenta percreta, which are assigned different scores respectively; ROC curve analysis is used for model verification.
5. A risk warning system based on the risk warning model for postpartum hemorrhage after secondary cesarean section according to any one of claims 1 to 4, characterized in that: The risk early warning system includes: Data collection module: input maternal clinical data and automatically match model risk factors; Risk assessment module: calculates the total score and bleeding risk probability based on the nomogram model; Early warning output module: generates visual risk level reports; Intervention recommendation module: Automatically push intervention plans for high-risk groups, including preoperative blood preparation, intraoperative hemostasis measures and postoperative monitoring strategies.
6. The risk warning system of the second cesarean section postpartum hemorrhage risk warning model according to claim 5, characterized in that: The data acquisition module is integrated with the hospital information system interface to support real-time retrieval of electronic medical record data.
7. The risk warning system of the second cesarean section postpartum hemorrhage risk warning model according to claim 6, characterized in that: The intervention recommendation module includes a hierarchical management strategy: Low risk: routine monitoring; Medium risk: Strengthen intraoperative hemostasis preparation; High risk: Initiate a multidisciplinary collaborative diagnosis and treatment process.
8. The risk warning system of the second cesarean section postpartum hemorrhage risk warning model according to claim 7, characterized in that: The risk warning system also includes a data encryption module.
9. A computer-readable storage medium for the risk warning model for postpartum hemorrhage after secondary cesarean section according to any one of claims 1 to 4, characterized in that: The medium stores a computer program, which, when executed, implements the following functions: Receive clinical data of women who underwent second cesarean section; Call the nomogram model to calculate the risk score; Output risk warning results and visualization reports.
10. A medical device according to any one of claims 1 to 4, wherein the model is used for warning the risk of postpartum hemorrhage after secondary cesarean section, The medical equipment includes: A processor for running a risk warning model algorithm; A display screen for displaying risk assessment results and intervention recommendations; Input device, used to enter maternal clinical data or connect external equipment.