Risk factors for blood transfusion in Cesarean section: A systematic review and meta-analysis

Predicting intraoperative blood loss during cesarean sections based on multi-modal information: a two-center study

PURPOSE

To develop and validate a nomogram model that combines radiomics features, clinical factors, and coagulation function indexes (CFI) to predict intraoperative blood loss (IBL) during cesarean sections, and to explore its application in optimizing perioperative management and reducing maternal morbidity.

METHODS

In this retrospective consecutive series study, a total of 346 patients who underwent magnetic resonance imaging (156 for training and 68 for internal test, center 1; 122 for external test, center 2) were included. IBL+ was defined as more than 1000 mL estimated blood loss during cesarean sections. The prediction models of IBL were developed based on machine-learning algorithms using CFI, radiomics features, and clinical factors. ROC analysis was performed to evaluate the performance for IBL diagnosis.

RESULTS

The support vector machine model incorporating all three modalities achieved an AUC of 0.873 (95% CI 0.769-0.941) and a sensitivity of 1.000 (95% CI 0.846-1.000) in the internal test set, with an AUC of 0.806 (95% CI 0.725-0.872) and a sensitivity of 0.873 (95% CI 0.799-0.922) in the external test set. It was also scored significantly higher than the CFI model (P = 0.035) on the internal test set, and both the CFI (P = 0.002) and radiomics-CFI models (P = 0.007) on the external test set. Additionally, the nomogram constructed based on three modalities achieved an internal testing set AUC of 0.960 (95% CI 0.806-0.999) and an external testing set AUC of 0.869 (95% CI 0.684-0.967) in the pregnant population without a pernicious placenta previa. It is noteworthy that the AUC of the proposed model did not show a statistically significant improvement compared to the Clinical-CFI model in both internal (P = 0.115) and external test sets (P = 0.533).

CONCLUSION

The proposed model demonstrated good performance in predicting intraoperative blood loss (IBL), exhibiting high sensitivity and robust generalizability, with potential applicability to other surgeries such as vaginal delivery and postpartum hysterectomy. However, the performance of the proposed model was not statistically significantly better than that of the Clinical-CFI model.

Effectiveness of non-pharmacological interventions to prevent anemia in pregnant women: a quantitative systematic review protocol

OBJECTIVE

This review will identify the effectiveness of non-pharmacological interventions in preventing iron deficiency anemia in pregnant women with a normal course of pregnancy.

INTRODUCTION

The global prevalence of anemia among pregnant women is 36.5%, posing risks to women and fetuses. This underscores the need for effective prevention; however, the effectiveness of non-pharmacological approaches in preventing pregnancy anemia remains unclear.

INCLUSION CRITERIA

This review will encompass experimental and quasi-experimental studies on the following approaches to prevent anemia during pregnancy: recommendations for dietary supplements, oral iron supplements (over the counter), provision of supplements to promote iron absorption, participation in anemia prevention education, and provision of information. There will be no restrictions on the duration or frequency of intervention, and longitudinal intervention studies will be included. In studies with a control group, the comparator may be usual care or pharmacological interventions; in studies without, it may involve no intervention, temporal comparisons, or baseline periods without non-pharmacological interventions. Evaluation of hemoglobin, hematocrit, and ferritin will be included as primary outcomes. Low birth weight, preterm birth, amount of blood loss at delivery, small for gestational age, and Apgar scores will be included as secondary outcomes.

METHODS

A search will be conducted in MEDLINE (Ovid), Embase, CINAHL (EBSCOhost), Scopus, Australian New Zealand Clinical Trials Registry, Cochrane Central Register of Controlled Trials, and ICHUSHI-Web. Researchers will screen studies, extract data, assess the quality of studies, and analyze the data in accordance with the JBI guidance for systematic reviews of effectiveness. The Grading of Recommendations, Assessment, Development and Evaluation approach will be used to assess the certainty of the findings.

REVIEW REGISTRATION

PROSPERO CRD42022344155.

Reconsidering Routine Repeat Group and Screens During Pregnancy-Personalizing Pregnancy Care

The group and screen (G&S) are performed in early pregnancy to identify clinically significant antibodies (CSA) that may necessitate fetal monitoring for hemolysis/anemia or affect RhIg eligibility. Guidelines vary, including differences between RhD-positive and negative patients, but typically, the G&S is repeated at 28 weeks, and sometimes pre-delivery. We reviewed data showing a low risk (0.01%-0.43%) of detecting a new CSA in late gestation (late alloimmunization) and the risk of late alloimmunization causing severe hemolysis/anemia is even lower at <0.01%. Routinely repeating a G&S at 28 weeks and delivery may not be necessary for healthy, low-risk pregnancies.

Factors and outcomes for placental anomalies: An umbrella review of systematic reviews and meta-analyses

Background

Placental anomalies, including placenta previa (PP), placenta accreta spectrum disorders (PAS), and vase previa (VP), are associated with several adverse foetal-neonatal and maternal complications. However, there is still a lack of robust evidence on the pathogenesis and adverse outcomes of the diseases. Through this umbrella review, we aimed to systematically review existing meta-analyses exploring the factors and outcomes for pregnancy women with placental anomalies.

Methods

We searched PubMed, Embase, Web of Science, and the Cochrane Library from inception to February 2023. We used AMSTAR 2 to assess the quality of the reviews and estimated the pooled risk and 95% confidence intervals (CIs) for each meta-analysis.

Results

We included 34 meta-analyses and extracted 55 factors (27 for PP, 22 for PAS, and 6 for VP) and 16 outcomes (12 for PP, and 4 for VP) to assess their credibility. Seven factors (maternal cocaine use (for PP), uterine leiomyoma (for PP), prior abortion (spontaneous) (PP), threatened miscarriage (PP), maternal obesity (PP), maternal smoking (PAS), male foetus (PAS)) had high epidemiological evidence. Twelve factors and six outcomes had moderate epidemiological evidence. Twenty-two factors and eight outcomes showed significant association, but with weak credibility.

Conclusions

We found varying levels of evidence for placental anomalies of different factors and outcomes in this umbrella review.

Registration

PROSPERO: CRD42022300160.