Nomogram to predict postpartum hemorrhage in cesarean delivery for women with scarred uterus: A retrospective cohort study in China

Placental T2-weighted MRI-based radiomics-clinical nomogram to predict postpartum hemorrhage of placenta previa

BACKGROUND

Placenta previa is an obstetric complication related to severe maternal morbidity and mortality. Magnetic resonance imaging (MRI) can be used for the preoperative evaluation of postpartum hemorrhage.

PURPOSE

To investigate the value of MRI-based radiomics analysis in predicting postpartum hemorrhage among pregnant women with placenta previa.

MATERIAL AND METHODS

Preoperative T2-weighted MRI and related clinical data of 371 patients were retrospectively collected, and these patients were randomly allocated into two subsets: the training dataset (n = 260) and the validation dataset (n = 111). The logistic regression (LR) classifier was used for the development of the radiomics model and the calculation of the radiomics score (Radscore).

RESULTS

A total of eight radiomics features and five clinical features were selected for model development. The area under the receiver operating characteristic curve (AUC) of the radiomics model in the training and validation datasets were 0.929 (95% confidence interval [CI] = 0.891-0.957) and 0.914 (95% CI = 0.846-0.959), respectively. Combined with clinical factors, nomograms demonstrated improved diagnostic efficacy, with an AUC of 0.968 (95% CI = 0.939-0.986) in the training dataset and 0.947 (95% CI = 0.888-0.981) in the validation dataset.

CONCLUSION

The MRI-based model has certain value in predicting postpartum hemorrhage in pregnant women with placenta previa.

Establishment of Risk Nomogram Model of Postpartum Hemorrhage After Second Cesarean Section

Objective

To establish and evaluate a nomogram model for predicting the risk of postpartum hemorrhage in second cesarean section.

Methods

A total of 440 parturients who underwent the second cesarean section surgery and were registered in our hospital from August 2019 to July 2021 were selected as the study subjects. They were randomly divided into 220 modeling group and 220 validation group based on simple randomization. The two groups were divided into postpartum hemorrhage group and postpartum non bleeding group according to whether postpartum hemorrhage occurred.

Results

In the modeling group, the incidence of postpartum hemorrhage in the second cesarean section was 15.00%; the Logistic regression model showed that placenta previa, operation time, prenatal anemia, placenta accreta, uterine inertia were the independent risk factors of postpartum hemorrhage in the second cesarean section (P < 0.05). ROC results showed that AUC of predicting the risk of postpartum hemorrhage in the second cesarean section was 0.824. The slope of calibration curve is close to 1, Hosmer-Lemeshow goodness of fit test showed x2= 7.585, P = 0.250. The external verification results show that the AUC is 0.840, and the predicted probability of the calibration curve is close to the actual probability.

Conclusion

Based on the five risk factors of postpartum hemorrhage in the second cesarean section, including placenta previa, operation time, prenatal anemia, placenta accreta and uterine inertia, the nomogram model for predicting the risk of postpartum hemorrhage in the second cesarean section has good accuracy and differentiation.

Analysis of risk factors associated with different degrees of postpartum hemorrhage in patients with pregnancy-induced hypertension and construction of a prediction model using line graph

OBJECTIVE

This study aims to analyze the risk factors associated with different degrees of postpartum hemorrhage in patients with pregnancy-induced hypertension and construct a prediction model using line graph.

METHODS

The patients who were treated in our hospital for pregnancy-induced hypertension from January 2021 to December 2022 were enrolled as the study subjects. Their clinical data were collected, and the risk factors associated with postpartum hemorrhage in patients with pregnancy-induced hypertension were analyzed by single-factor and multi-factor logistic regression. The nomogram prediction model was constructed and validated internally, and the discrimination and consistency of the model were verified by the ROC curve and calibration graph.

RESULTS

In this experiment, 125 out of the 482 patients with hypertensive disorder complicating pregnancy experienced different degrees of postpartum hemorrhage, with an incidence of 25.93%. Multivariate Logistic regression analysis showed that patients with severe disease (OR = 2.454), the degree of proteinuria +++ or ++++ (OR = 6.754, 7.206), fetal body mass ≥4000 g (OR = 5.972), uterine atony (OR = 11.789), abnormal HDL-C (OR = 3.174), abnormal LDL-C (OR = 8.812), and abnormal VEGF (OR = 7.702) had a higher risk of postpartum hemorrhage (p < .05). The risk of postpartum hemorrhage was lower in patients with onset gestational week ≥28 weeks (OR = 0.158, 0.025) and delivery gestational week ≥28 weeks (OR = 0.085, 0.152) (p < .05). Columnar line graph models for postpartum hemorrhage in patients with gestational hypertension were constructed based on nine independent risk factors, and the model differentiation (AUC 0.912 and 0.919, respectively) and precision (goodness of fit HL χ2 = 8.441, p = .392, χ2 = 7.741, p = .459) were better in the modeling and validation groups.

CONCLUSION

The severity of disease, the gestational week upon onset, the gestational week upon delivery, the degree of proteinuria, systolic blood pressure, diastolic blood pressure, uterine atony, HDL-C, LDL-C, VEGF are factors affecting the incidence of postpartum hemorrhage in patients with hypertensive disorder complicating pregnancy. The prediction model based on the above factors can accurately evaluate the risk of different degrees of postpartum hemorrhage in patients with hypertensive disorder complicating pregnancy.

Perinatal Outcomes of Pregnancy in Women with Scarred Uteri

Objective

Uterine scarring is risky for the pregnancy and is closely associated with adverse pregnancy outcomes. Here, we investigated risk factors and associated perinatal outcomes in singleton pregnant women with uterine scars.

Methods

This retrospective cohort study was conducted on singleton pregnant women who delivered at the West China Second University Hospital between January 1, 2021, and December 31, 2021.

Results

The control group included 13,433 cases without uterine scars. The study group involved 2397 cases with one previous cesarean delivery (PCD), 163 cases with two PCDs, 12 cases with three PCDs, and 184 cases with non-cesarean uterine scars. The study group had a significantly higher incidence of placenta previa (6.4%), placenta percreta (5.3%), preterm delivery (10.3%), postpartum hemorrhage (3.4%), uterine rupture (9.4%), hysterectomy (0.18%), and bladder injury (0.4%) when compared with the control group (P <0.05). The scarred uterus cases with 1, 2, or 3 PCDs had significantly different complications, with the higher PCD frequency correlating with increased rates of placenta previa, placenta percreta, postpartum hemorrhage, uterine rupture, and uterine resection. Moreover, the hospitalization time, cesarean operation time, and intrapartum bleeding in the current pregnancy significantly increased with increasing PCD frequency (P <0.05). Analysis of the association between the duration of the interval between PCD and re-pregnancy and pregnancy complication revealed that the incidence of pernicious placenta previa was statistically higher in cases with intervals of <2 years or ≥5 years (4.7%) than in cases with 2 years ≤ interval time <5 years (2.5%) (P <0.05).

Conclusion

Pregnancies with uterine scars may experience higher rates of adverse perinatal outcomes. This calls for increased observation during pregnancy and delivery to reduce maternal and fetal complications.

Incidence of postpartum hemorrhage based on the improved combined method in evaluating blood loss: A retrospective cohort study

OBJECTIVE

In view of the current clinical inaccuracies and underestimations of postpartum hemorrhage amount, this study aims to investigate the incidence, etiology, clinical characteristics of postpartum hemorrhage in different modes of delivery based on the combination of volumetric method, gravimetric method and area method in evaluating blood loss.

DESIGN

This retrospective cohort study was conducted in Hangzhou Women's Hospital from January 2020 to June 2021, including 725 cases of postpartum hemorrhage among 18,977 parturients. Based on different modes of delivery, the participants were divided into three groups: vaginal delivery, forceps delivery, and cesarean section, for comparison.

METHODS

Using an improved combined assessment method for blood loss, we retrospectively analyzed a cohort of parturients with postpartum hemorrhage who underwent vaginal delivery, forceps delivery, or cesarean section and were hospitalized in Hangzhou Women's Hospital from January 2020 to June 2021.

RESULTS

(1) Among the 18,977 parturients, 725 cases of postpartum hemorrhage occurred, with an incidence rate of 3.8%, and severe postpartum hemorrhage accounted for 0.4% of the cases. (2) The incidence of postpartum hemorrhage was significantly higher in the forceps delivery group than in the vaginal delivery group (χ2 = 19.27, P<0.001), while the incidence of severe postpartum hemorrhage was significantly higher in the cesarean section group than in the vaginal delivery group (χ2 = 8.71, P = 0.003). (3) The causes of postpartum hemorrhage were statistically different among the different delivery modes, with varying underlying factors (P<0.001). (4) Patients with postpartum hemorrhage in different delivery modes showed statistically significant differences in age, body mass index (BMI), birth weight, gestational age, gravidity, parity, the decline of postpartum peripheral blood hemoglobin concentration, and estimated blood loss (P<0.05). (5) The proportion of blood transfusion was significantly higher in the cesarean section group than in the vaginal delivery and forceps delivery groups (χ2 = 231.03, P<0.001).

LIMITATIONS

This study is a single-center retrospective study, which may have led to selection bias in case selection. Additionally, the implementation of the combined three blood loss assessment methods may not have been strictly followed in all cases. Moreover, due to the mixing of bleeding with amniotic and irrigation fluids, the accuracy of evaluation may have been affected, leading to the possibility of inaccuracy of blood loss.

CONCLUSIONS

Forceps delivery and cesarean section increase the risk of postpartum hemorrhage, but forceps delivery does not significantly increase the incidence of severe postpartum hemorrhage. Uterine atony remains the leading cause of postpartum hemorrhage, while birth canal laceration and placental factors are the second most common causes of postpartum hemorrhage in forceps delivery and cesarean section, respectively. In this study, the volumetric method, gravimetric method and area method were combined to quantitatively assess postpartum hemorrhage amount. The combined method has strong clinical practicability and is less affected by subjective factors, although it also has limitations. In the future, we still need to focus on the early prediction and identification of postpartum hemorrhage, and further improve the quantitative assessment of postpartum blood loss.

A risk prediction nomogram of endometrial carcinoma and precancerous lesions in postmenopausal women: A retrospective study

This study aimed to develop a risk prediction nomogram for endometrial carcinoma and precancerous lesions in postmenopausal women to provide postmenopausal patients with more information on disease probability, work out personalized medical plans, and reduce unnecessary invasive clinical examinations. We enrolled 340 patients who underwent hysteroscopy at Beijing Maternity Hospital between March 2016 and July 2018. The patients were divided into the low-risk (275 patients) and high-risk (65 patients) groups, according to the results of the pathological examinations. Binary logistic analysis was performed to evaluate the 20 potential risk factors for endometrial cancer and precancerous lesions in postmenopausal women and to screen for certain risk factors using the Statistical Package for the Social Sciences version 26.0. Using R 4.0.3, we built a prediction nomogram that incorporated the selected factors. The discrimination, calibration, and clinical usefulness of the prediction model were assessed using the concordance (C)-index, calibration plot, and decision curve analysis. Internal validation was assessed using bootstrapping validation. Predictors included in the prediction nomogram included obesity, vaginal bleeding, family history of gynecological malignancies, endometrial thickness ≥ 1.15 cm, and color Doppler flow imaging blood flow. The model displayed good discrimination, with a C-index of 0.853, and good calibration. Decision curve analysis showed that the model was clinically useful, with a benefit range of 2% to 93%. A high C-index value of 0.844 could still be reached in the interval validation. Obesity, vaginal bleeding, family history of gynecological malignancies, endometrial thickness ≥ 1.15 cm, and color Doppler flow imaging blood flow were independent risk factors for endometrial cancer and precancerous lesions. Thus, the prediction nomogram can be conveniently used to facilitate individual risk prediction in patients with endometrial cancer and precancerous lesions.

Risk-factor model for postpartum hemorrhage after cesarean delivery: a retrospective study based on 3498 patients

This study aimed to investigate the risk factors of patients with postpartum hemorrhage (PPH) after cesarean delivery (CD) and to develop a risk-factor model for PPH after CD. Patients were selected from seven affiliated medical institutions of Chongqing Medical University from January 1st, 2015, to January 1st, 2020. Continuous and categorical variables were obtained from the hospital's electronic medical record systems. Independent risk factors were identified by univariate analysis, least absolute shrinkage and selection operator and logistic regression. Furthermore, logistic, extreme gradient boosting, random forest, classification and regression trees, as well as an artificial neural network, were used to build the risk-factor model. A total of 701 PPH cases after CD and 2797 cases of CD without PPH met the inclusion criteria. Univariate analysis screened 28 differential indices. Multi-variable analysis screened 10 risk factors, including placenta previa, gestational age, prothrombin time, thrombin time, fibrinogen, anemia before delivery, placenta accreta, uterine atony, placental abruption and pregnancy with uterine fibroids. Areas under the curve by random forest for the training and test sets were 0.957 and 0.893, respectively. The F1 scores in the random forest training and test sets were 0.708. In conclusion, the risk factors for PPH after CD were identified, and a relatively stable risk-factor model was built.

Prenatal Diagnosis Nomograms: A Novel Tool to Predict Fetal Chromosomal Abnormalities in High-Risk Patients

Background

Amniocentesis is an invasive prenatal diagnostic technique that can provide genetic information of fetus for pregnant women and give them a choice. A straightforward predictive tool can show pregnant women the need for amniocentesis prior to the procedure.

Methods

The information of patients who underwent amniocentesis from 2014 to 2019 at the Obstetrics Clinic, Shengjing Hospital of China Medical University was extracted, and important independent prognostic factors were determined by univariate and multivariate logistic regression analysis to construct nomograms with total abnormalities (TA) and chromosome number abnormalities (CNA).

Results

A total of 19,683 patients undergoing amniocentesis were included in this study. Among 1761 patients with abnormal results, 917 had abnormal chromosome numbers, 439 had abnormal chromosome structures, and 405 had polymorphic results. Nomograms of TA and CNA were created using data such as age, nuchal translucency value, ultrasound results, Oscar’s testing and/or non-invasive prenatal testing abnormalities, parental chromosomes, and information whether they were twins. The nomogram has good predictive power and clinical practicality through the analysis of area under curve and decision curve analysis. Internal verification was performed for nomograms of TA and CNA, suggesting that the nomogram’s predicted probability and actual probability of the two are consistent.

Conclusion

The nomogram constructed is a good predictor of TA and CNA, which can be used in clinical practice to screen high-risk patients of chromosomal abnormalities.