The more you lose the more you miss: accuracy of postpartum blood loss visual estimation. A systematic review of the literature

Application of Predictive Analytics in Pregnancy, Birth, and Postpartum Nursing Care

ABSTRACT

Predictive analytics has emerged as a promising approach for improving reproductive health care and patient outcomes. During pregnancy and birth, the ability to accurately predict risks and complications could enable earlier interventions and reduce adverse events. However, there are challenges and ethical considerations for implementing predictive models in perinatal care settings. We introduce major concepts in predictive analytics and describe application of predictive modeling to perinatal care topics such as fertility, preeclampsia, labor onset, vaginal birth after cesarean, uterine rupture, induction outcomes, postpartum hemorrhage, and postpartum mood disorders. Although some predictive models have achieved adequate accuracy (AUC 0.7-0.9), most require additional external validation across diverse populations and practice settings. Bias, particularly racial bias, remains a key limitation of current models. Nurses and advanced practice nurses, including nurse practitioners certified registered nurse anesthetists, and nurse-midwives, play a vital role in ensuring high-quality data collection and communicating predictive model outputs to clinicians and users of the health care system. Addressing the ethical challenges and limitations of predictive analytics is imperative to equitably translate these tools to support patient-centered perinatal care.

Postpartum hemorrhage: risk factors for severe blood loss, surgical intervention and peripartum hysterectomy

PURPOSE

To evaluate risk factors in patients presenting with postpartum hemorrhage (PPH) associated with severe blood loss (BL), surgical intervention or peripartum hysterectomy.

METHODS

This retrospective cohort study included all patients who gave birth at the Hannover Medical School between January 2013 and August 2022 with PPH, defined as BL ≥ 500 ml after vaginal delivery and ≥ 1000 ml after cesarean section. The threshold for severe PPH was set at BL ≥ 1500 ml. Operative management included manual placental removal and/or aspiration/curettage, need for intrauterine balloon tamponade, uterine packing with a chitosan covered gauze or compression sutures. Hysterectomy as ultima ratio was observed separately.

RESULTS

In total 20.9% of 1038 patients with PPH developed severe BL. Several risk factors were identified such as nicotine abuse (aOR 3.45, 95% CI 1.57-7.59, p = 0.002), multiparity (aOR 2.12, 95% CI 1.10-4.10, p = 0.03), uterine malformation (aOR 5.09, 95% CI 1.22-21.16, p = 0.03), c-section (aOR 3.92, 95% CI 2.59-5.92, p < 0.001), placenta praevia (aOR 2.82, 95% CI 1.2-6.63, p = 0.02), abnormal placentation (aOR 9.76, 95% CI 4.22-22.56, p < 0.001) and inversion of the uterus (aOR 16.89, 95% CI 1.62-176.12, p = 0.02). More than one third of the women had a surgical intervention. Independent risk factors for an operative management of PPH were uterus malformation (aOR 5.04, 95% CI 1.22-20.91, p = 0.03), placenta praevia (aOR 2.84, 95% CI 1.23-6.53, p = 0.01), abnormal placentation (aOR 9.78, 95% CI 4.30-22.27, p < 0.001) and c-section (aOR 4.65, 95% CI 3.14-6.89, p < 0.001). Peripartum hysterectomy occurred in 1.9% of the cases and was in addition independently associated wih preeclampsia (aOR 7.50, 95% CI 1.29-43.81, p = 0.03) and amniotic infection syndrome (aOR 12.22, 95% CI 1.92-77.90, p = 0.01).

CONCLUSION

PPH is a common complication in modern obstetrics and one in five patients with pathological bleeding after birth develops severe BL. There are specific risk factors associated with a BL ≥ 1500 ml, surgical intervention and peripartum hysterectomy in PPH that should be assessed by health professionals and taken into account in the management of this postpartum complication.

Association Between Laboratory Coagulation Parameters and Postpartum Hemorrhage in Preterm and Term Caesarean Section: A Retrospective Analysis

Background: Deranged antepartum laboratory parameters may be risk factors for postpartum hemorrhage (PPH). However, whether this is also valid in women who give birth prematurely is currently unknown. Methods: We performed a retrospective single-center study to assess the role of antepartum hemoglobin, platelet count, fibrinogen, activated partial thromboplastin time, and prothrombin time as risk factors for PPH following caesarean section. We defined PPH as documented blood loss of at least 1 L and/or transfusion of red blood cell concentrates. We stratified the included patients according to gestational age: extremely preterm (gestational age < 28 weeks), very preterm (gestational age between 28 and 32 weeks), late and moderate preterm (gestational age between 32 and 37 weeks), and term (gestational age ≥ 37 weeks). Results: We included 1734 patients, 112 (6%) of whom had PPH. In total, 19 patients (10%) were in the extremely preterm group, 13 patients (10%) were in the very preterm group, 44 patients (9%) were in the late and moderate preterm group, and 36 patients (4%) were in the term group. Hemoglobin predicted PPH in all gestational age groups. Platelet count was associated with PPH in term, but not in preterm patients. Fibrinogen was associated with PPH in late prematurity but not in term patients and not in patients with early or extreme prematurity. Conclusions: Antepartum hemoglobin was the only factor predicting PPH in preterm and term caesarean sections. Platelet count and fibrinogen concentration were associated with PPH in term and late prematurity, respectively, but not in earlier stages of prematurity.

Trends in severe postpartum haemorrhage among nulliparous women with spontaneous onset of labour: A population-based cohort study

OBJECTIVE

To investigate the incidence of severe postpartum haemorrhage among nulliparous women with a spontaneous onset of labour at term from 2000 to 2020.

DESIGN

Population-based cohort study.

SETTING

National, using the Medical Birth Registry of Norway.

POPULATION

Women (n = 330 244) who gave birth to their first singleton child in a cephalic presentation after a spontaneous onset of labour at term.

METHODS

Cross-tabulations and regression analysis with generalised linear models were used to assess time trends and adjust for potential confounding factors. We also stratified the analyses by maternal age groups, obstetric interventions, mode of delivery and institution size. Time trends were analysed using periods of 5 or 6 years as a unit, and the period from 2000 to 2004 was used as the reference.

MAIN OUTCOME MEASURES

Severe postpartum haemorrhage (PPH) was defined as blood loss of >1500 mL within 24 h and/or in combination with blood transfusion.

RESULTS

Severe PPH occurred in 7601/330 244 (2.30%) women. The incidence increased from 1.24% in 2000-2004 to 3.83% in 2015-2020 (adjusted relative risk, aRR 2.90; 95% CI 2.70-3.12). Changes in maternal characteristics or obstetric interventions did not explain the increase, and we found similar increases across institutions of all sizes.

CONCLUSIONS

The incidence of severe PPH among nulliparous women increased almost threefold over 21 years. The current high incidence warrants urgent efforts to assess unknown risk factors, the health care provided and health system factors that may contribute to the increase, to inform improvements in care.

Roles and challenges encountered by midwives in the management of postpartum haemorrhage following normal vaginal delivery: A scoping review

AIMS

To establish a comprehensive understanding of the roles of midwives and the challenges they encounter in the prevention, diagnosis and management of postpartum haemorrhage (PPH) following normal vaginal delivery.

DESIGN

We conducted a scoping review following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis for Scoping Reviews (PRISMA-ScR) recommendations.

METHODS

We considered studies related to the roles of midwives and the challenges they encounter in the prevention, diagnosis and management of PPH during vaginal delivery. We excluded guidelines, consensuses, abstracts of meetings and non-English language studies. Databases, including the Cochrane Library, PubMed, Web of Science, Ovid, Medline, Embase, JBI EBP and BIOSIS Previews, were searched on January 1, 2023, with no time limitations.

RESULTS

We included 28 publications. Midwives play important roles in the prevention, diagnosis and management of postpartum haemorrhage during vaginal delivery. In the prevention of PPH, midwives' roles include identifying and managing high-risk factors, managing labour and implementing skin-to-skin contact. In the diagnosis of PPH, midwives' roles include early recognition and blood loss estimation. In the management of PPH, midwives are involved in mobilizing other professional team members, emergency management, investigating causes, enhancing uterine contractions, the repair of perineal tears, arranging transfers and preparation for surgical intervention. However, midwives face substantial challenges, including insufficient knowledge and skills, poor teamwork skills, insufficient resources and the need to deal with their negative emotions. Midwives must improve their knowledge, skills and teamwork abilities. Health care system managers and the government should give full support to midwives. Future research should focus on developing clinical practice guidelines for midwives for preventing, diagnosing and managing postpartum haemorrhage.

Development and evaluation of a wearable peripheral vascular compensation sensor in a swine model of hemorrhage

Postpartum hemorrhage (PPH) is the leading and most preventable cause of maternal mortality, particularly in low-resource settings. PPH is currently diagnosed through visual estimation of blood loss or monitoring of vital signs. Visual assessment routinely underestimates blood loss beyond the point of pharmaceutical intervention. Quantitative monitoring of hemorrhage-induced compensatory processes, such as the constriction of peripheral vessels, may provide an early alert for PPH. To this end, we developed a low-cost, wearable optical device that continuously monitors peripheral perfusion via laser speckle flow index (LSFI) to detect hemorrhage-induced peripheral vasoconstriction. The measured LSFI signal produced a linear response in phantom models and a strong correlation coefficient with blood loss averaged across subjects (>0.9) in a large animal model, with superior performance to vital sign metrics.

Evaluation During Postpartum Hemorrhage

Postpartum hemorrhage is an obstetric emergency that is the leading and the most preventable cause of maternal death that occurs on the day of birth. The treatment of postpartum hemorrhage in a timely fashion is crucial to prevent morbidity and mortality. The accurate assessment of blood loss during delivery and the postpartum period remains a major challenge. Hence, it is imperative to have a standardized evaluation strategy for accurate assessment of blood loss, adequate classification of hemorrhage, and timely initiated interventions. The multidisciplinary evaluation strategy should be in place regardless of the delivery route.

Postpartum Hemorrhage and Tranexamic Acid: A Literature Review

This review aims to explore the postpartum hemorrhage (PPH) burden and the efficacy of prophylactic tranexamic acid (TXA) in PPH and recent indications of TXA. A comprehensive review of the literature was conducted using a combination of Medical Subject Headings keywords including "Postpartum haemorrhage," "Tranexamic acid," and "Cesarean section." PPH has been explored for epidemiology, risk factors, and pathophysiology in the first part of the article. Recent indications of TXA, obstetric indications, and the role of TXA as prophylaxis for PPH are discussed in the second part of this article. TXA has many indications apart from obstetric indications and shows a significant effect in controlling bleeding. Furthermore, TXA is more efficient in preventing PPH if administered during the final stage of labor and is a valuable option for managing obstetric bleeding.

Development and evaluation of a wearable peripheral vascular compensation sensor in a swine model of hemorrhage

Postpartum hemorrhage (PPH) is both the leading and most preventable cause of maternal mortality. PPH is currently diagnosed through visual estimation of blood loss or vital sign analysis of shock index (ratio of heart rate to systolic blood pressure). Visual assessment underestimates blood loss, particularly in the setting of internal bleeding, and compensatory mechanisms stabilize hemodynamics until hemorrhage is massive, beyond the point of pharmaceutical intervention. Quantitative monitoring of hemorrhage-induced compensatory processes, such as the constriction of peripheral vessels to shunt blood to the central organs, may provide an early alert for PPH. To this end, we developed a low-cost, wearable optical device that continuously monitors peripheral perfusion via laser speckle flow index (LSFI) to detect hemorrhage-induced peripheral vasoconstriction. The device was first tested using flow phantoms across a range of physiologically relevant flow rates and demonstrated a linear response. Subsequent testing occurred in swine hemorrhage studies (n=6) by placing the device on the posterior side of the swine's front hock and withdrawing blood from the femoral vein at a constant rate. Resuscitation with intravenous crystalloids followed the induced hemorrhage. The mean LSFI vs. percent estimated blood volume loss had an average correlation coefficient of -0.95 during the hemorrhage phase and 0.79 during resuscitation, both of which were superior to the performance of the shock index. With continued development, this noninvasive, low-cost, and reusable device has global potential to provide an early alert of PPH when low-cost and accessible management strategies are most effective, helping to reduce maternal morbidity and mortality from this largely preventable problem.

Oxytocin receptor DNA methylation is associated with exogenous oxytocin needs during parturition and postpartum hemorrhage

BACKGROUND

The oxytocin receptor gene (OXTR) is regulated, in part, by DNA methylation. This mechanism has implications for uterine contractility during labor and for prevention or treatment of postpartum hemorrhage, an important contributor to global maternal morbidity and mortality.

METHODS

We measured and compared the level of OXTR DNA methylation between matched blood and uterine myometrium to evaluate blood as an indicator of uterine methylation status using targeted pyrosequencing and sites from the Illumina EPIC Array. Next, we tested for OXTR DNA methylation differences in blood between individuals who experienced a postpartum hemorrhage arising from uterine atony and matched controls following vaginal birth. Bivariate statistical tests, generalized linear modeling and Poisson regression were used in the analyses.

RESULTS

Here we show a significant positive correlation between blood and uterine DNA methylation levels at several OXTR loci. Females with higher OXTR DNA methylation in blood had required significantly more exogenous oxytocin during parturition. With higher DNA methylation, those who had oxytocin administered during labor had significantly greater relative risk for postpartum hemorrhage (IRR 2.95, 95% CI 1.53-5.71).

CONCLUSIONS

We provide evidence that epigenetic variability in OXTR is associated with the amount of oxytocin administered during parturition and moderates subsequent postpartum hemorrhage. Methylation can be measured using a peripheral tissue, suggesting potential use in identifying individuals susceptible to postpartum hemorrhage. Future studies are needed to quantify myometrial gene expression in connection with OXTR methylation.

Oxytocin receptor single nucleotide polymorphism predicts atony-related postpartum hemorrhage

BACKGROUND

Postpartum hemorrhage remains a key contributor to overall maternal morbidity in the United States. Current clinical assessment methods used to predict postpartum hemorrhage are unable to prospectively identify about 40% of hemorrhage cases. Oxytocin is a first-line pharmaceutical for preventing and treating postpartum hemorrhage, which acts through oxytocin receptors on uterine myocytes. Existing research indicates that oxytocin function is subject to variation, influenced in part by differences in the DNA sequence within the oxytocin receptor gene. One variant, rs53576, has been shown to be associated with variable responses to exogenous oxytocin when administered during psychological research studies. How this variant may influence myometrial oxytocin response in the setting of third stage labor has not been studied. We tested for differences in the frequency of the oxytocin receptor genotype at rs53576 in relationship to the severity of blood loss among a sample of individuals who experienced vaginal birth.

METHODS

A case-control prospective design was used to enroll 119 postpartum participants who underwent vaginal birth who were at least 37 weeks of gestation. Cases were defined by either a 1000 mL or greater blood loss or instances of heavier bleeding where parturients were given additional uterotonic treatment due to uterine atony. Controls were matched to cases on primiparity and labor induction status. Genotype was measured from a maternal blood sample obtained during the 2^nd postpartum month from 95 participants. Statistical analysis included bivariate tests and generalized linear and Poisson regression modeling.

RESULTS

The distribution of the genotype across the sample of 95 participants was 40% GG (n = 38), 50.5% AG (n = 48) and 9.5% AA (n = 9). Blood loss of 1000 mL or greater occurred at a rate of 7.9% for GG, 12.5% for AG and 55.6% for AA participants (p = 0.005). Multivariable models demonstrated A-carriers (versus GG) had 275.2 mL higher blood loss (95% CI 96.9-453.4, p < 0.01) controlling for parity, intrapartum oxytocin, self-reported ancestry, active management of third stage or genital tract lacerations. Furthermore, A-carrier individuals had a 79% higher risk for needing at least one second-line treatment (RR = 1.79, 95% CI = 1.08-2.95) controlling for covariates. Interaction models revealed that A-carriers who required no oxytocin for labor stimulation experienced 371.4 mL greater blood loss (95% CI 196.6-546.2 mL).

CONCLUSIONS

We provide evidence of a risk allele in the oxytocin receptor gene that may be involved in the development of postpartum hemorrhage among participants undergoing vaginal birth, particularly among those with fewer risk factors. The findings, if reproducible, could be useful in studying pharmacogenomic strategies for predicting, preventing or treating postpartum hemorrhage.

Maternal body weight and estimated circulating blood volume: a non-linear approach

Postpartum haemorrhage continues to be a leading cause of morbidity and mortality in the obstetric population worldwide, especially in patients at extremes of body weight. Quantification of blood loss has been considered extensively in the literature. However, these volumes must be contextualised to appreciate the consequences of blood loss for individual parturients. Knowledge of a patient's peripartum circulating blood volume is essential to allow accurate interpretation of the significance of haemorrhage and appropriate resuscitation. Greater body weight in obesity can lead to overestimation of blood volume, resulting in inappropriately high thresholds for blood product transfusion and delays in treatment. The most recent Mothers and Babies: Reducing Risk through Audits and Confidential Enquiries across the UK (MBRRACE-UK) surveillance report demonstrated the risk to this population, with more than half of all maternal mortality recorded in parturients who were either overweight or obese. Current linear calculations used to estimate circulating blood volumes based on patients' weights could be contributing to this phenomenon, as blood volume increases at a disproportional rate to body composition. In this review, we summarise the relevant physiology and explore the existing literature on the estimation of circulating blood volume, both during pregnancy and in obesity. Building on key works and principal findings, we present a practical, nonlinear approach to the adjustment of estimated blood volume with increasing body mass. This clinical tool aims to reduce the clinical bias influencing the management of obstetric haemorrhage in a population already at increased risk of morbidity and mortality. Discussion of the limitations of this approach and the call for further research within this field completes this review.

Emergencies in obstetric anaesthesia: a narrative review

We conducted a narrative review in six areas of obstetric emergencies: category-1 caesarean section; difficult and failed airway; massive obstetric haemorrhage; hypertensive crisis; emergencies related to neuraxial anaesthesia; and maternal cardiac arrest. These areas represent significant research published within the last five years, with emphasis on large multicentre randomised trials, national or international practice guidelines and recommendations from major professional societies. Key topics discussed: prevention and management of failed neuraxial technique; role of high-flow nasal oxygenation and choice of neuromuscular drug in obstetric patients; prevention of accidental awareness during general anaesthesia; management of the difficult and failed obstetric airway; current perspectives on the use of tranexamic acid, fibrinogen concentrate and cell salvage; guidance on neuraxial placement in a thrombocytopenic obstetric patient; management of neuraxial drug errors, local anaesthetic systemic toxicity and unusually prolonged neuraxial block regression; and extracorporeal membrane oxygenation use in maternal cardiac arrest.

Determining the incidence of postpartum haemorrhage among Ontario women with and without inherited bleeding disorders: A population-based cohort study

INTRODUCTION

At a population level, there is a poor understanding of the incidence and pre-disposing risk factors of postpartum haemorrhage (PPH) among women with inherited bleeding disorders (IBD).

AIM

To determine the incidence of PPH, and identify maternal factors associated with risk of PPH among women with IBD.

METHODS

We conducted a retrospective cohort study using data housed within ICES (formerly known as the Institute for Clinical Evaluative Sciences). The cohort included women with an in-hospital, live or stillborn delivery, between January 2014 and December 2019. The primary outcome was PPH (identified by ICD-10 code O72). PPH incidence and risk factors were compared between women with and without IBD. Temporal trends were assessed using the Cochrane-Armitage test. Between group differences were assessed using standardised differences (std. difference).

RESULTS

Total 601,773 women were included; 2002 (.33%) had an IBD diagnosis. PPH incidence was 1.5 times higher (7.3 vs. 4.9 cases/100 deliveries, std. difference .1) among women with IBD compared to women without. Women with IBD were slightly older (31.7 vs. 30.7 years), had higher rates of hypertension, previous PPH, and induction of labour. Women with IBD were more frequently diagnosed with anaemia (4.8% vs. 1.8%; std difference .17) and had lower haemoglobin levels at admission for delivery compared to women without IBD.

CONCLUSIONS

This study contributes to the literature regarding obstetric bleeding among women with IBD, showing that anaemia at delivery may be an important risk factor for PPH. Given their predisposition to anaemia, clarifying this relationship will optimise management and outcomes.

Comparing Postpartum Estimated and Quantified Blood Loss Among Racial Groups: An Observational Study

Objective: Racial and ethnic disparities in peripartum blood loss and postpartum hemorrhage (PPH) have not been adequately evaluated. We sought to compare postpartum blood loss and PPH in African American and Hispanic parturients compared to other groups.

Methods: This was a secondary analysis of an observational study at a tertiary academic center of a historical (August 2016 to January 2017) and interventional (August 2017 to January 2018) cohort of 7618 deliveries. Visual estimation of blood loss (EBL) was used in the historical group and quantitative blood loss (QBL) was implemented in the intervention group. Our primary endpoint was median blood loss in African Americans versus other racial groups between cohorts.

Results: A total of 7618 deliveries were evaluated; 755 (9.9%) were identified as African American with 1035 (13.6%) identifying as Hispanic. Blood loss was similar in racial groups using EBL (p=0.131), but not QBL that was 430 (227-771) in African Americans and 348 (200-612) in non-African Americans (p<0.001). PPH was greater among African Americans in both groups (10.3% vs. 6.9% in EBL cohort, p=0.023, and 16.9% vs. 11.6% in QBL cohort, p<0.001).

Conclusion: Racial and ethnic differences in peripartum blood loss were more apparent with QBL than EBL. It is unknown if these differences are caused by provider cognitive bias, socioeconomic differences, language barriers and/or other factors.

Latest advances in postpartum hemorrhage management

Hemorrhage is the leading cause of maternal mortality worldwide. A maternal health priority is improving how healthcare providers prevent and manage postpartum hemorrhage (PPH). Because anesthesiologists can help facilitate how hospitals develop approaches for PPH prevention and anticipatory planning, we review the potential utility of PPH risk-assessment tools, bundles, and protocols. Anesthesiologists rely on clinical and diagnostic information for initiating and evaluating medical management. Therefore, we review modalities for measuring blood loss after delivery, which includes visual, volumetric, gravimetric, and colorimetric approaches. Point-of-care technologies for assessing changes in central hemodynamics (ultrasonography) and coagulation profiles (rotational thromboelastometry and thromboelastography) are also discussed. Anesthesiologists play a critical role in the medical and transfusion management of PPH. Therefore, we review blood ordering and massive transfusion protocols, fixed-ratio vs. goal-directed transfusion approaches, coagulation changes during PPH, and the potential clinical utility of the pharmacological adjuncts, tranexamic acid, and fibrinogen concentrate.

Estimating blood loss during cesarean delivery: A comparison of methods

Objectives

Obstetrical hemorrhage contributes significantly to maternal morbidity and mortality. Assessment of blood loss while undergoing cesarean sections (CS) is essential in lowering the morbidity and mortality, however this amount is commonly underestimated by the surgeon and probably the anesthetist too.

Methods

This study addresses this issue by comparing three separate ways of assessing blood loss during cesarean sections. For each of 97 full-term pregnant women undergoing elective CS, blood loss was measured by the following: visual estimation by both the obstetrician and the anesthetist, weighing surgical pads pre operatively and post operatively and by calculations (multiplying the difference of pre-operative and postoperative hemoglobin values by the patient's estimated blood volume).

Results

The results of this study indicated that the lowest estimated value for blood loss came from visual estimation, while the highest value came from the mathematical formula. Anesthetists were more accurate in their visual estimation of blood loss than were obstetricians.

Conclusion

This study found the amount of blood loss during CS to be overestimated by the mathematical calculation and underestimated by obstetricians. However, the estimate given by anesthetists was close to that obtained by weighing pads. This underscores the need for more accurate methods of blood loss estimation in cesarean sections to be adopted.

Understanding How Health Providers Identify Women with Postpartum Hemorrhage: A Qualitative Study

OBJECTIVE

 To identify how health providers recognize postpartum hemorrhage early and the difficulties involved in it.

METHODS

 An exploratory, descriptive study using a qualitative approach through a semi-structured interview technique. In total, 27 health professionals (nursing technicians, nurses, medical residents in Gynecology and Obstetrics, hired medical doctors, and medicine professors) working in a tertiary-level hospital of reference in women's health care in the State of São Paulo, Brazil, participated in the study through an invitation. After they accepted the invitation, they signed the free and informed consent form. All interviews were recorded and transcribed, and a thematic analysis was conducted. We found three analysis categories: a) perception of the severity: "there is something wrong with the women"; b) difficulties in the early diagnosis of postpartum hemorrhage; and c) the process to improve obstetrical care.

RESULTS

 Caregivers believe teamwork and communication should be improved. Besides the visual estimation of blood loss, the nursing team is attentive to behavioral symptoms like irritability, while the medical staff follow protocols and look for objective signs, such as altered vital signs.

CONCLUSION

 Besides the objective evaluations, the subjective perceptions of the providers are involved in the clinical judgement regarding the diagnosis of postpartum hemorrhage, and this should be included in a broader diagnosis strategy.

Can measuring blood loss at delivery reduce hemorrhage-related morbidity?

Quantitation of blood loss after vaginal and cesarean delivery has been advocated for the timely detection of postpartum hemorrhage and activation of protocols for resuscitation. Morbidity and mortality from postpartum hemorrhage is considered to be largely preventable and is attributed to delayed recognition with under-resuscitation or inappropriate resuscitation. Optimizing detection of postpartum hemorrhage through refining how blood loss is measured is therefore clinically relevant. In this review on quantitative blood loss for postpartum hemorrhage, recent advances in the methods used to quantitate blood loss will be reviewed, with a comparison of utility and precision for blood loss measurement after vaginal and cesarean delivery. Considerations for the implementation of a quantitative blood loss system on the labor and delivery unit, including its benefits and challenges, will be discussed. The existing evidence for impact of blood loss quantitation in obstetrics on hemorrhage-related morbidity will be delineated, along with knowledge gaps and future research priorities.

Hospital discharge data is not accurate enough to monitor the incidence of postpartum hemorrhage

INTRODUCTION

Postpartum hemorrhage remains a leading cause of maternal morbidity and mortality worldwide. Therefore, cumulative incidence of postpartum hemorrhage and severe postpartum hemorrhage are commonly monitored within and compared across maternity hospitals or countries for obstetrical safety improvement. These indicators are usually based on hospital discharge data though their accuracy is seldom assessed. We aimed to measure postpartum hemorrhage and severe postpartum hemorrhage using electronic health records and hospital discharge data separately and compare the detection accuracy of these methods to manual chart review, and to examine the temporal trends in cumulative incidence of these potentially avoidable adverse outcomes.

MATERIALS AND METHODS

We analyzed routinely collected data of 7904 singleton deliveries from a large Swiss university hospital for a three year period (2014-2016). We identified postpartum hemorrhage and severe postpartum hemorrhage in electronic health records by text mining discharge letters and operative reports and calculating drop in hemoglobin from laboratory tests. Diagnostic and procedure codes were used to identify cases in hospital discharge data. A sample of 334 charts was reviewed manually to provide a reference-standard and evaluate the accuracy of the other detection methods.

RESULTS

Sensitivities of detection algorithms based on electronic health records and hospital discharge data were 95.2% (95% CI: 92.6% 97.8%) and 38.2% (33.3% to 43.0%), respectively for postpartum hemorrhage, and 87.5% (85.2% to 89.8%) and 36.2% (26.3% to 46.1%) for severe postpartum hemorrhage. Postpartum hemorrhage cumulative incidence based on electronic health records decreased from 15.6% (13.1% to 18.2%) to 8.5% (6.7% to 10.5%) from the beginning of 2014 to the end of 2016, with an average of 12.5% (11.8% to 13.3%). The cumulative incidence of severe postpartum hemorrhage remained at approximately 4% (3.5% to 4.4%). Hospital discharge data-based algorithms provided significantly underestimated incidences.

CONCLUSIONS

Hospital discharge data is not accurate enough to assess the incidence of postpartum hemorrhage at hospital or national level. Instead, automated algorithms based on structured and textual data from electronic health records should be considered, as they provide accurate and timely estimates for monitoring and improvement in obstetrical safety. Furthermore, they have the potential to better code for postpartum hemorrhage thus improving hospital reimbursement.

Postpartum hemorrhage in Suriname: A national descriptive study of hospital births and an audit of case management

Background

Postpartum hemorrhage (PPH) is the leading cause of direct maternal mortality globally and in Suriname. We aimed to study the prevalence, risk indicators, causes, and management of PPH to identify opportunities for PPH reduction.

Methods

A nationwide retrospective descriptive study of all hospital deliveries in Suriname in 2017 was performed. Logistic regression analysis was applied to identify risk indicators for PPH (≥ 500ml blood loss). Management of severe PPH (blood loss ≥1,000ml or ≥500ml with hypotension or at least three transfusions) was evaluated via a criteria-based audit using the national guideline.

Results

In 2017, the prevalence of PPH and severe PPH in Suriname was 9.2% (n = 808/8,747) and 2.5% (n = 220/8,747), respectively. PPH varied from 5.8% to 15.8% across the hospitals. Risk indicators associated with severe PPH included being of African descent (Maroon aOR 2.1[95%CI 1.3–3.3], Creole aOR 1.8[95%CI 1.1–3.0]), multiple pregnancy (aOR 3.4[95%CI 1.7–7.1]), delivery in Hospital D (aOR 2.4[95%CI 1.7–3.4]), cesarean section (aOR 3.9[95%CI 2.9–5.3]), stillbirth (aOR 6.4 [95%CI 3.4–12.2]), preterm birth (aOR 2.1[95%CI 1.3–3.2]), and macrosomia (aOR 2.8 [95%CI 1.5–5.0]). Uterine atony (56.7%, n = 102/180[missing 40]) and retained placenta (19.4%, n = 35/180[missing 40]), were the main causes of severe PPH. A criteria-based audit revealed that women with severe PPH received prophylactic oxytocin in 61.3% (n = 95/155[missing 65]), oxytocin treatment in 68.8% (n = 106/154[missing 66]), and tranexamic acid in 4.9% (n = 5/103[missing 117]).

Conclusions

PPH prevalence and risk indicators in Suriname were similar to international and regional reports. Inconsistent blood loss measurement, varied maternal and perinatal characteristics, and variable guideline adherence contributed to interhospital prevalence variation. PPH reduction in Suriname can be achieved through prevention by practicing active management of the third stage of labor in every birth and considering risk factors, early recognition by objective and consistent blood loss measurement, and prompt treatment by adequate administration of oxytocin and tranexamic acid according to national guidelines.

Factors affecting third-stage management and postpartum hemorrhage in planned midwife-led home and birth center births in the United States

BACKGROUND

Postpartum hemorrhage (PPH) is a potential childbirth complication. Little is known about how third-stage labor is managed by midwives in the United States, including use of uterotonic medication during community birth. Access to uterotonic medication may vary based on credentials of the midwife or state regulations governing midwifery.

METHODS

Using data from the Midwives of North America 2.0 database (2004-2009), we describe the PPH incidence for women giving birth in the community, their demographic and clinical characteristics, and methods used by midwives to address PPH. We also examined PPH rates by midwifery credentials and by the presence of regulations for legal midwifery practice.

RESULTS

Of the 17 836 vaginal births, 15.9% had blood loss of over 500 mL and 3.3% had 1000 mL or greater blood loss. Midwives used pharmaceuticals to prevent or treat postpartum bleeding in 6.3% and 13.9% of births, respectively, and the rate of hospital transfer after birth was 1.4% (n = 247). In adjusted analyses, PPH was less likely when births occurred at home vs a birth center, if the midwife had a CNM/CM credential vs a CPM/LM/LDM credential, or if the woman was multiparous without a history of PPH or prior cesarean birth. PPH was more likely in states with barriers to midwifery practice compared with regulated states (OR: 1.26; 95% CI, 1.16-1.38).

CONCLUSIONS

Women giving birth in the community experienced low overall incidence of PPH-related hospital transfer. However, the occurrence of PPH itself would likely be reduced with improved legal access to uterotonic medication.

Visual estimates of blood loss by medical laypeople: Effects of blood loss volume, victim gender, and perspective

A severe hemorrhage can result in death within minutes, before professional first responders have time to arrive. Thus, intervention by bystanders, who may lack medical training, may be necessary to save a victim's life in situations with bleeding injuries. Proper intervention requires that bystanders accurately assess the severity of the injury and respond appropriately. As many bystanders lack tools and training, they are limited in terms of the information they can use in their evaluative process. In hemorrhage situations, visible blood loss may serve as a dominant cue to action. Therefore, understanding how medically untrained bystanders (i.e., laypeople) perceive hemorrhage is important. The purpose of the current study was to investigate the ability of laypeople to visually assess blood loss and to examine factors that may impact accuracy and the classification of injury severity. A total of 125 laypeople watched 78 short videos each of individuals experiencing a hemorrhage. Victim gender, volume of blood lost, and camera perspective were systematically manipulated in the videos. The results revealed that laypeople overestimated small volumes of blood loss (from 50 to 200 ml), and underestimated larger volumes (from 400 to 1900 ml). Larger volumes of blood loss were associated with larger estimation errors. Further, blood loss was underestimated more for female victims than male victims and their hemorrhages were less likely to be classified as life-threatening. These results have implications for training and intervention design.

Predicting Postpartum Hemorrhage After Low-Risk Vaginal Birth by Labor Characteristics and Oxytocin Administration

OBJECTIVE

To determine the odds of postpartum hemorrhage (PPH) in low-risk women who gave birth vaginally and were exposed to different durations and dosages of oxytocin across a range of labor durations during spontaneous or induced labor.

DESIGN

A retrospective cross-sectional analysis of data from the Consortium for Safe Labor.

SETTING

Data were gathered from 12 clinical institutions across the United States from 2002 to 2008.

PARTICIPANTS

After exclusion of high-risk conditions associated with PPH, we examined data from 27,072 women who gave birth vaginally.

METHODS

PPH was defined as estimated blood loss of greater than 500 ml at the time of birth and/or a diagnostic code for PPH before hospital discharge. We included covariates were if they were associated with oxytocin use and PPH and did not mediate oxytocin use. We used regression models to determine the likelihood of PPH overall and within the induced and spontaneous labor groups separately. We used subgroup analyses within specific durations of labor to clarify the findings.

RESULTS

The overall rate of PPH was 3.9%. Women with induced labor experienced PPH more frequently than women who labored spontaneously. Labor augmentation was associated with greater adjusted odds for PPH when oxytocin was infused for more than 4 hours. Longer duration of spontaneous labor and the second stage of labor did not change this association. Oxytocin use during labor induction increased the odds for PPH when administered for more than 7 hours. The odds further increased when induction lasted longer than 12 hours and/or the second stage of labor was longer than 3 hours.

CONCLUSION

Strategies for judicious oxytocin administration may help mitigate PPH in low-risk women having vaginal birth.

Carbetocin versus Oxytocin for the Prevention of Postpartum Hemorrhage in Cesarean Deliveries: A Retrospective Study of Two Consecutive Periods

Objective  The aim of the study is to investigate whether carbetocin prevents postpartum hemorrhage (PPH) more effectively than oxytocin Methods  This historical retrospective single-center cohort study compares women who underwent cesarean deliveries during two periods. During period A, oxytocin was used as a 10-unit bolus immediately after delivery, with 20 units thereafter infused for 24 hours. During period B, carbetocin in a single 100-µg injection replaced this protocol. The main outcome was PPH, defined as a decline in hemoglobin of more than 2 g/dL after the cesarean. The analysis was performed on the overall population and then stratified by the timing of the cesareans (before or during labor). A logistic regression analysis was performed. Results  This study included 1,796 women, 52% of whom had a cesarean before labor; 15% had a PPH. The crude PPH rate was lower in period B than in period A (13 vs. 17%, respectively, odds ratio 0.75, 95% confidence interval [CI]: 0.58-0.98). The difference was no longer significant in the multivariate analysis (adjusted odds ratio: 0.81, 95% CI 0.61-1.06). Results were similar when stratified by the timing of the cesareans (before or during labor). Conclusion  Carbetocin is not superior to oxytocin in preventing PPH. However, it does provide the advantage of requiring a single injection.

Episiotomy: a medicolegal vicious cycle

The present study aimed to analyze the litigation trends and ensuing compensatory damages brought about by the use of episiotomy, in order to outline a set of cautionary rules meant to limit the scope of legreal aftermath for both doctors and health care facilities. The authors have set out to gain an insight into the controversial practice of episiotomy, in light of available research data and official positions of various scientific and medical associations, with a close focus on the legal and medical viability of the procedure itself. Court data and trial records have been taken into account as well, via searches into legal databases and search engines (Justia, Lexis, Jurist.org, Venice Courthouse, etc.). This review showed that most episiotomy-related lawsuits stemmed from a routine use of that procedure, which is almost universally advised against, and without valid informed consent having been gained. Ultimately, authors have seen fit to underscore the need for patients potentially eligible for an episiotomy (selective episiotomy) to receive thorough and understandable information in a timely fashion including the necessity and the effectiveness of the procedure as well as the risks involved, so that a well-informed decision can be made based on factual data.

Major obstetric haemorrhage in Metro East, Cape Town, South Africa: a population-based cohort study using the maternal near-miss approach

Background

Major obstetric haemorrhage is a leading cause of maternal mortality and accounts for one-third of maternal deaths in of Africa. This study aimed to assess the population-based incidence, causes, management and outcomes of major obstetric haemorrhage and risk factors associated with poor maternal outcome.

Methods

Women with major obstetric haemorrhage who met the WHO maternal near-miss criteria or died in the Metro East region, Cape Town, South Africa, were evaluated from November 2014–November 2015. Major obstetric haemorrhage was defined as haemorrhage in pregnancies of at least 20 weeks’ gestation or occurring up to 42 days after birth, and leading to hysterectomy, hypovolaemic shock or blood transfusion of ≥5 units of Packed Red Blood Cells. A logistic regression model was used to analyse associations with poor outcome, defined as major obstetric haemorrhage leading to massive transfusion of ≥8 units of packed red blood cells, hysterectomy or death.

Results

The incidence of major obstetric haemorrhage was 3/1000 births, and the incidence of massive transfusion was 4/10.000 births in the Metro East region (32.862 births occurred during the studied time period). Leading causes of haemorrhage were placental abruption 45/119 (37.8%), complications of caesarean section 29/119 (24.4%) and uterine atony 13/119 (10.9%). Therapeutic oxytocin was administered in 98/119 (82.4%) women and hysterectomy performed in 33/119 (27.7%). The median numbers of packed red blood cells and units of Fresh Frozen Plasma transfused were 6 (interquartile range 4–7) and 3 (interquartile range 2–4), ratio 1.7:1. Caesarean section was independently associated with poor maternal outcome: adjusted OR 4.01 [95% CI 1.58, 10.14].

Conclusions

Assessment of major obstetric haemorrhage using the Maternal Near Miss approach revealed that placental abruption and complications of caesarean section were the major causes of major obstetric haemorrhage. Caesarean section was associated with poor outcome.

Development of an assessment and intervention protocol for postpartum hemorrhage in the mainland of China: an evidence-based method and Delphi consult

Objective

Postpartum hemorrhage (PPH) is a leading cause of maternal death. Although guidelines have been updated, those with detailed protocols are limited for nursing practice. This study aims at establishing an early assessment and intervention protocol as a toolkit for PPH for midwives and obstetrical nurses.

Methods

Employing the evidence-based method, a systematic Internet search of guidelines was conducted and appraisal of literatures was conducted with AGREE system and Oxman-Guyatt Overview Quality Assessment Questionnaire (OQAQ), according to which a protocol draft was therefore developed. Then, a two-round modified Delphi method was utilized to reach a consensus of the protocol built on best practices. Selection criteria for each intervention measure included consensus level with a threshold of 70%, mean of importance (M) >3.5, and coefficient of variation (CV) <0.25. Reliability of experts’ opinion was calculated by positive coefficient and authoritative coefficient. Items without consistency were enlisted in the second-round consult. When all items met the selection criteria, the protocol would be finally formulated.

Results

A 122-measure protocol was established, including prevention, assessment, and intervention of PPH. With a panel of 14 experts participated in the consult, the positivity coefficient was 0.93 and 1.00 for two rounds, respectively, and the authority coefficient was 0.88. After a two-round consult and revision of the draft, the final program was formulated, containing 5 first-level indexes and 14 second-level indexes with a total item of 120.

Conclusions

The PPH protocol, based on high-quality evidences, was formulated with a two-round Delphi method, which can provide insight for midwives and obstetrical nurses to effectively deal with PPH.

Management of post-partum hemorrhage and the role of the obstetric anesthesiologist

PURPOSE OF REVIEW

The landscape of post-partum hemorrhage management is rapidly changing. Modifications to definitions, bundles, and care plans occur frequently with management strategies becoming more complex. It has become apparent that the management of these patients requires a multidisciplinary approach with the involvement of obstetricians, anesthesiologists, gynecologist/oncologists, nursing, and care associates. This review article is meant to be an evidence-based review of post-partum hemorrhage with practical recommendations and a look at future directions of the management of post-partum hemorrhage from the vantage point of the obstetric anesthesiologist in an effort to enhance the collaborative treatment of this at risk population.

Validation of a quantitative system for real-time measurement of postpartum blood loss

PURPOSE

Reliable real-time estimation of blood loss is crucial for the prompt management of postpartum hemorrhage (PPH), which is one of the major obstetric complications worldwide. Our study aims at the validation of feasibility and precision of measured blood loss (MBL) with a quantitative real-time measurement system during (1) vaginal delivery and (2) cesarean section by comparison with a hemoglobin-based formula for blood loss as an objective control. This is the first study to include a reasonable number of patients in an everyday clinical setting.

METHODS

921 patients were prospectively enrolled into this study (vaginal delivery: n = 461, cesarean delivery: n = 460) at a tertiary care hospital in Switzerland. Blood loss was measured by quantitative fluid collection bags. "Calculated blood loss" (CBL) was determined by modified Brecher`s formula based on the drop of hemoglobin after delivery. MBL based on our measurement system was compared to CBL by correlation analysis and stratified by the mode of delivery.

RESULTS

During vaginal delivery, MBL as determined by our quantitative measurement system highly correlated with CBL (p < 0.001, r = 0.683). This was also true for patients with cesarean deliveries (p < 0.001, r = 0.402), however, in a less linear amount. In women with cesarean deliveries, objectively low blood loss tended to be rather overestimated, while objectively high blood loss was more likely underestimated.

CONCLUSIONS

The technique of real-time measurement of postpartum blood loss after vaginal delivery as presented in this study is practicable, reliable and strongly correlated with the actual blood loss and, therefore, poses an actual improvement in the management of PPH.

Identifying the risk: a prospective cohort study examining postpartum haemorrhage in a regional Australian health service

Background

In industrialised countries the incidence of postpartum haemorrhage (PPH) is increasing, for which exact etiology is not well understood. Studies have relied upon retrospective data with estimated blood loss as the primary outcome, known to be underestimated by clinicians. This study aimed to explore variables associated with PPH in a cohort of women birthing vaginally in coastal Queensland, Australia, using the gravimetric method to measure blood loss.

Methods

Women were prospectively recruited to participate using an opt-out consent process. Maternal demographics; pregnancy history; model of care; mode of birth; third stage management practices; antenatal, intrapartum and immediate postpartum complications; gravimetric and estimated blood loss; and haematological laboratory data, were collected via a pre-designed data collection instrument. Descriptive statistics were used for demographic, intrapartum and birthing practices. A General Linear Model was used for multivariate analysis to examine relationship between gravimetric blood loss and demographic, birthing practices and intrapartum variables. The primary outcome was a postpartum haemorrhage (blood loss > 500 ml).

Results

522 singleton births were included in the analysis. Maternal mean age was 29 years; 58% were multiparous. Most participants received active (291, 55.7%) or modified active management of third stage (191, 36.6%). Of 451 births with valid gravimetric blood loss recorded, 35% (n = 159) recorded a loss of 500 ml or more and 111 (70%) of these were recorded as PPH. Gravimetric blood loss was strongly correlated with estimated blood loss (r = 0.88; p < 0.001). On average, the estimated blood loss was lower than the gravimetric blood loss, about 78% of the measured value. High neonatal weight, perineal injury, complications during labour, separation of mother and baby, and observation of a gush of blood were associated with PPH. Nulliparity, labour induction and augmentation, syntocinon use were not associated with PPH.

Conclusions

In contrast to previous study findings, nulliparity, labour induction and augmentation were not associated with PPH. Estimation of blood loss was relatively accurate in comparison to gravimetric assessment; raising questions about routine gravimetric assessment of blood loss following uncomplicated births. Further research is required to investigate type and speed of blood loss associated with PPH.