Inability to predict postpartum hemorrhage: insights from Egyptian intervention data

Postpartum haemorrhage following vaginal delivery: a comprehensive analysis and development of predictive models for aetiological subgroups in Chinese women

OBJECTIVES

This study aimed to dissect the aetiological subgroups of postpartum haemorrhage (PPH) that occur after vaginal delivery in women with full-term singleton pregnancies. Our goal was to craft and validate predictive models to guide clinical decision-making and optimise resource allocation.

DESIGN

A retrospective cohort study.

SETTING

Shengjing Hospital of China Medical University, Liaoning Maternal and Child Health Hospital, and Shenyang Women's and Children's Hospital.

PARTICIPANTS

29 842 women who underwent vaginal delivery were enrolled in the study across three hospitals from 2016 to 2022.

PRIMARY OUTCOME MEASURES

PPH, categorised into uterine atony (UA), placental factors (PF), cervical trauma (CT), and coagulation abnormalities (CA) by aetiology.

RESULTS

The logistic regression for overall PPH and UA-PPH showcased high discrimination (AUCs of 0.807 and 0.794, respectively), coupled with commendable calibration and DCA-assessed clinical utility, culminating in the development of a nomogram for risk prediction. The PF-PPH model exhibited a modest AUC of 0.739, while the CT-PPH and CA-PPH models demonstrated suboptimal clinical utility and calibration.

CONCLUSION

The study identified factors associated with PPH and developed models with good performance for overall PPH and UA-PPH. The nomogram offers a valuable tool for risk prediction. However, models for PF-PPH, CT-PPH, and CA-PPH require further refinement. Future research should focus on larger samples and multicentre validation for enhanced model generalisability.

Placental biomarkers in second trimester maternal serum are associated with postpartum hemorrhage: a secondary analysis of the NuMoM2b dataset

Postpartum hemorrhage (PPH) is the leading cause of maternal mortality worldwide, which is often attributed to retained placenta (RP) after delivery. There are no biomarkers currently used to predict a risk of developing RP/PPH prior to labor. The objective of this study was to determine relationships between placental biomarkers measured in the first and second trimesters and proxy measures of postpartum blood loss relative to preeclampsia status in the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be (nuMoM2b) dataset. 2,192 participants had placental analytes drawn during the first and second trimesters (9-13 and 16-22 weeks gestation, respectively); the outcome was a composite of retained placenta and/or PPH requiring blood transfusion (RP/PPH). Using Kruskal-Wallis tests, median differences in levels of soluble fms-like tyrosine kinase-1 (sFlt-1), placental growth factor (PlGF), sFlt-1/PlGF ratio, soluble endoglin (sEng), beta subunit of human chorionic gonadotropin (β-hCG), inhibin A (INHA), and pregnancy-associated protein-A (PAPP-A) were assessed between women with (n=67) and without (n=2125) RP/PPH overall and stratified by preeclampsia status. Women with RP/PPH had significantly higher median levels of sEng, β-hCG, INHA, PAPP-A in the second trimester and sFlt-1was higher in both first and second trimesters, which was observed again when stratifying by preeclampsia status. Our findings indicate that biomarkers associated with angiogenesis, particularly when measured in the second trimester, are important targets for further study of RP and/or PPH pathophysiology and potential risk screening development.

Intrauterine Postpartum Hemorrhage-Control Devices

Postpartum hemorrhage , defined as a cumulative blood loss of 1,000 mL or more or blood loss associated with signs or symptoms of hypovolemia regardless of the route of delivery, is the leading cause of preventable maternal death worldwide. The United States has one of the highest maternal mortality rates among developed countries, with about 14% of all maternal deaths associated with postpartum hemorrhage. Although postpartum hemorrhage has multiple causes, the most common is uterine atony-when the uterus fails to adequately contract after childbirth-accounting for 80% of all postpartum hemorrhages. When postpartum hemorrhage occurs despite preventive measures, therapeutic measures are used. Intrauterine hemorrhage-control devices are often the second-line therapy when medical management is unsuccessful. Despite its widespread use in current obstetric practice, the mechanism of intrauterine balloon tamponade, such as the Bakri balloon, is counterintuitive to the physiologic uterine contraction that occurs after delivery to control bleeding, and data on its effectiveness are mixed. Vacuum-induced hemorrhage control, such as with the Jada System, cleared by the U.S. Food and Drug Administration in 2020, is a novel modality for control of postpartum bleeding. It mimics postpartum physiology by applying low-level intrauterine negative pressure to facilitate uterine compressive forces, thereby constricting blood vessels to achieve hemostasis. Preliminary data from four studies are promising but are limited by a lack of control groups, selection bias, or modest sample sizes. The results of ongoing and planned randomized controlled trials will clarify the role of the Jada System for reducing morbidity from postpartum hemorrhage.

Hemostatic biomarkers associated with postpartum hemorrhage: a systematic review and meta-analysis

Postpartum hemorrhage (PPH) is a leading cause of maternal morbi-mortality. Although obstetric risk factors are well described, the impact of predelivery hematologic and hemostatic biomarkers remains incompletely understood. In this systematic review, we aimed to summarize the available literature on the association between predelivery hemostatic biomarkers and PPH/severe PPH. Searching MEDLINE, EMBASE, and CENTRAL databases from inception to October 2022, we included observational studies on unselected pregnant women without bleeding disorder reporting on PPH and on predelivery hemostatic biomarkers. Two review authors independently performed title, abstract and full-text screening, upon which quantitative syntheses of studies reporting on the same hemostatic biomarker were conducted, calculating the mean difference (MD) between women with PPH/severe PPH and controls. A search on 18 October 2022 yielded 81 articles fitting our inclusion criteria. The heterogeneity between studies was considerable. With regard to PPH, the estimated average MD in the investigated biomarkers (platelets, fibrinogen, hemoglobin, Ddimer, activated partial thromboplastin time, and prothrombin time) were not statistically significant. Women who developed severe PPH had lower predelivery platelets than controls (MD = -26.0 109/L; 95% confidence interval, -35.8 to -16.1), whereas differences in predelivery fibrinogen concentration (MD = -0.31 g/L; 95% confidence interval, -0.75 to 0.13) and levels of factor XIII or hemoglobin were not statistically significant in women with and without severe PPH. Predelivery platelet counts were, on average, lower in women with severe PPH compared with controls, suggesting the potential usefulness of this biomarker for predicting severe PPH. This trial was registered at the International Prospective Register of Systematic Reviews as CRD42022368075.

Fibrinolytic potential as a risk factor for postpartum hemorrhage

Background

Postpartum hemorrhage (PPH) is still the leading cause of maternal morbidity and mortality worldwide. While impaired fibrin polymerization plays a crucial role in the development and progress of PPH, recent approaches using viscoelastic measurements have failed to sensitively detect early changes in fibrinolysis in PPH. This study aimed to evaluate whether women experiencing PPH show alterations in POC-VET fibrinolytic potential during childbirth and whether fibrinolytic potential offers benefits in the prediction and treatment of PPH.

Methods

Blood samples were collected at three different timepoints: T0 = hospital admission (19 h ± 18 h prepartum), T1 = 30-60 min after placental separation, and T2 = first day postpartum (19 h ± 6 h postpartum). In addition to standard laboratory tests, whole-blood impedance aggregometry (Multiplate) and viscoelastic testing (VET) were performed using the ClotPro system, which included the TPA-test lysis time, to assess the POC-VET fibrinolytic potential, and selected coagulation factors were measured. The results were correlated with blood loss and clinical outcome markers. Severe PPH was defined as a hemoglobin drop > 4g/dl and/or the occurrence of shock or the need for red blood cell transfusion.

Results

Blood samples of 217 parturient women were analyzed between June 2020 and December 2020 at Heidelberg University Women's Hospital, and 206 measurements were eligible for the final analysis. Women experiencing severe PPH showed increased fibrinolytic potential already at the time of hospital admission. When compared to non-PPH, the difference persisted 30-60 min after placental separation. A higher fibrinolytic potential was accompanied by a greater drop in fibrinogen and higher d-dimer values after placental separation. While 70% of women experiencing severe PPH showed fibrinolytic potential, 54% of those without PPH showed increased fibrinolytic potential as well.

Conclusion

We were able to show that antepartal and peripartal fibrinolytic potential was elevated in women experiencing severe PPH. However, several women showed high fibrinolytic potential but lacked clinical signs of PPH. The findings indicate that high fibrinolytic potential is a risk factor for the development of coagulopathy, but further conditions are required to cause PPH.

Tranexamic acid for the prevention of blood loss after cesarean section: an updated systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

Tranexamic acid is a cost-effective intervention for the prevention of postpartum hemorrhage among women who undergo cesarean delivery, but the evidence to support its use is conflicting. We conducted this meta-analysis to evaluate the efficacy and safety of tranexamic acid in low- and high-risk cesarean deliveries.

DATA SOURCES

We searched MEDLINE (via PubMed), Embase, the Cochrane Library, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform portal from inception to April 2022 (updated October 2022 and February 2023) with no language restrictions. In addition, grey literature sources were also explored.

STUDY ELIGIBILITY CRITERIA

All randomized controlled trials that investigated the prophylactic use of intravenous tranexamic acid in addition to standard uterotonic agents among women who underwent cesarean deliveries in comparison with a placebo, standard treatment, or prostaglandins were included in this meta-analysis.

METHODS

We used the revised Cochrane Risk of Bias tool (RoB 2.0) to assess the quality of the included randomized controlled trials. RevMan 5.4 was used to conduct all statistical analyses using a random-effects model.

RESULTS

We included 50 randomized controlled trials (6 in only high-risk patients and 2 with prostaglandins as the comparator) that evaluated tranexamic acid in our meta-analysis. Tranexamic acid reduced the risk for blood loss >1000 mL, the mean total blood loss, and the need for blood transfusion in both low- and high-risk patients. Tranexamic acid was associated with a beneficial effect in the secondary outcomes, including a decline in hemoglobin levels and the need for additional uterotonic agents. Tranexamic acid increased the risk for nonthromboembolic adverse events but, based on limited data, did not increase the incidence of thromboembolic events. The administration of tranexamic acid before skin incision, but not after cord clamping, was associated with a large benefit. The quality of evidence was rated as low to very low for outcomes in the low-risk population and moderate for most outcomes in the high-risk subgroup.

CONCLUSION

Tranexamic acid may reduce the risk for blood loss in cesarean deliveries with a higher benefit observed in high-risk patients, but the lack of high-quality evidence precludes any strong conclusions. The administration of tranexamic acid before skin incision, but not after cord clamping, was associated with a large benefit. Additional studies, especially in the high-risk population and focused on evaluating the timing of tranexamic acid administration, are needed to confirm or refute these findings.

Incidence and predictors of severe postpartum hemorrhage after cesarean delivery in South Central Ethiopia: a retrospective cohort study

Severe postpartum hemorrhage is an obstetric emergency that needs immediate intervention and is a leading cause of maternal death. Despite its significant health burden, little is known, about its magnitude and risk factors, especially after cesarean delivery in Ethiopia. This study aimed to evaluate the incidence and predictors of severe postpartum hemorrhage following cesarean section. This study was conducted on 728 women who underwent cesarean section. We retrospectively collected data from the medical records, including baseline characteristics, obstetrics, and perioperative data. Potential predictors were investigated using multivariate logistic regression analyses, adjusted odd ratios, and a 95% confidence interval to see associations. A p-value < 0.05 is considered statistically significant. The incidence of severe postpartum hemorrhage was 26 (3.6%). The independently associated factors were previous CS scar ≥ 2 (AOR 4.08: 95% CI 1.20-13.86), antepartum hemorrhage (AOR 2.89: 95% CI 1.01-8.16), severe preeclampsia (AOR 4.52: 95% CI 1.24-16.46), maternal age ≥ 35 years (AOR 2.77: 95% CI 1.02-7.52), general anesthesia (AOR 4.05: 95% CI 1.37-11.95) and classic incision (AOR 6.01: 95% CI 1.51-23.98). One in 25 women who gave birth during cesarean section experienced severe postpartum hemorrhage. Considering appropriate uterotonic agents and less invasive hemostatic interventions for high-risk mothers would help to decrease its overall rate and related morbidity.

Design of a postpartum hemorrhage and transfusion risk calculator

Background

Postpartum hemorrhage is the major cause of maternal deaths due to childbirth and also responsible for maternal morbidity.

Objectives

In this study we set out to look the incidence of postpartum hemorrhage in our population, to identify the most important risk factors for postpartum hemorrhage and thus develop a predictive risk calculator for postpartum hemorrhage and transfusion.

Study design

data was taken from patients who presented vaginal delivery or cesarean section from January 1 to December 31, 2016, the variables taken into account as risk factors were as follows: Gestational age, history of chronic or gestational hypertension, preeclampsia, previous abortions, parity, previous cesarean section, placenta previa, labor time, and postpartum hemorrhage as the event of interest. An objective quantification was performed on a weight scale in grams for the estimation of bleeding, considering postpartum hemorrhage those with >500 ml in vaginal delivery and >1000 ml of blood loss in cesarean section. Subsequently, a predictive risk calculator was developed using the Naïve Bayes algorithm.

Results

A success rate of 58% was obtained in the identification of patients at high risk of hemorrhage, and 36% for transfusion, with a sensitivity of 50.7% and specificity of 64.06%, identifying as risk factors for postpartum hemorrhage gestational age between 35 and 40 weeks, hypertension and preeclampsia, previous cesarean section, duration of labor <1 h or more than 10 h, placenta previa and previous history of postpartum hemorrhage.

Conclusion

A postpartum hemorrhage risk calculator has been designed, which due to its improved accuracy after incorporation of data becomes a useful tool that will require a larger study population to improve its performance in clinical practice and more similar studies to validate it.

Prepartum Anemia and Risk of Postpartum Hemorrhage: A Meta-Analysis and Brief Review

Postpartum hemorrhage (PPH) is responsible for 30% to 50% of maternal deaths. There is conflicting evidence if prepartum anemia facilitates PPH. A comprehensive analysis of studies describing their relation is missing. An extensive database search was conducted applying the terms "anemia" OR "hemoglobin" AND "postpartum hemorrhage." We used a random-effects meta-analysis model to estimate an overall odds ratio (OR) for PPH and prepartum anemia, separating studies that were conformant and non-conformant with the World Health Organization (WHO) definitions for anemia. The search yielded 2519 studies, and 46 were appropriate for analysis. The meta-analyses of WHO-conformant (n = 22) and non-conformant (n = 24) studies showed that the risk of PPH was increased when anemia was present. The ORs were 1.45 (CL: 1.23-1.71) for WHO-conformant studies, 2.88 (CL: 1.38-6.02) for studies applying lower thresholds for anemia, and 3.28 (CL: 2.08-5.19) for undefined anemia thresholds. PPH risk appeared to increase with lower anemia thresholds. Prepartum anemia is associated with an increased risk of PPH, an observation that is important regarding improved anemia correction strategies such as iron supplementation.

The association between preterm delivery and postpartum bleeding in otherwise uncomplicated pregnancies

Objective

The primary aim was to investigate whether preterm delivery was an independent risk factor for blood or blood products transfusion in the intrapartum or postpartum period, considered as a proxy for severe obstetric bleeding.

Material and Methods

Throughout a 9-month-period, 216 uncomplicated singleton deliveries were included in a cross-sectional study after exclusion of severe maternal and fetal morbidity, such as chorioamnionitis, and use of medications including tocolytics. Maternal and neonatal data were evaluated and compared across preterm (between 24 0/7-36 6/7 weeks’ gestation) and term (between 37 0/7-41 6/7 weeks’ gestation) deliveries. Primary and secondary outcomes were requirement for blood or blood products transfusion until discharge and change in hemoglobin value and hematocrit from baseline to postpartum hour 6, respectively. Logistic regression models were constructed to evaluate the effect of preterm delivery on the primary outcome.

Results

There were 90 (41.7%) preterm deliveries with an overall cesarean section rate of 77.8%. Preterm delivery was not an independent risk factor for the primary outcome, when route of delivery, maternal body-mass index, antenatal steroid administration, and baseline (admission) platelet and leukocyte counts were controlled for [adjusted risk ratio, 2.46; 95% confidence interval (CI), 0.69-8.77; p=0.16]. Subgroup analysis, including cesarean deliveries, revealed a similar result (adjusted risk ratio, 1.65; 95% CI, 0.42-6.48; p=0.47). Secondary outcomes, including decrease in mean or percent values of hemoglobin and hematocrit measurements, were also similar across preterm and term groups, both after vaginal and cesarean delivery (for all comparisons, p>0.05).

Conclusion

Preterm delivery is not independently associated with increased requirement for blood transfusions or decreased hemoglobin and hematocrit values following otherwise uncomplicated vaginal or cesarean delivery of singletons.

Incidence, mortality, and factors associated with primary postpartum haemorrhage following in-hospital births in northwest Ethiopia

BACKGROUND

Of the 1010 reported maternal deaths in 2018, just over 65% occurred in hospitals in Ethiopia. However, there is a lack of standardised data about the contributing factors. This study aimed to investigate the incidence, mortality, and factors associated with primary postpartum haemorrhage following in-hospital births in northwest Ethiopia.

METHODS

A retrospective cohort design was used; an audit of 1060 maternity care logbooks of adult women post-partum at Felege Hiwot Referral Hospital and University of Gondar Comprehensive Specialized Hospital. The data were abstracted between December 2018 and May 2019 using a systematic random sampling technique. We used the Facility Based Maternal Death Abstraction Form containing sociodemographic characteristics, women's medical history, and partographs. Primary postpartum haemorrhage was defined as the estimated blood loss recorded by the staff greater or equal to 500 ml for vaginal births and 1000 ml for caesarean section births, or the medical doctor diagnosis and recording of the woman as having primary postpartum haemorrhage. The data analysis was undertaken using Stata version 15. Variables with P ≤ 0.10 for significance were selected to run multivariable logistic analyses. Variables that had associations with primary postpartum haemorrhage were identified based on the odds ratio, with 95% confidence interval (CI) and P-value less than 0.05.

RESULTS

The incidence of primary postpartum haemorrhage in the hospitals was 8.8% (95% CI: 7.2, 10.6). Of these, there were 7.4% (95% CI: 2.1, 13.3) maternal deaths. Eight predictor variables were found to be independently associated with primary postpartum haemorrhage, including age ≥35 years (AOR: 2.20; 95% CI: 1.08, 4.46; P = 0.03), longer than 24 hours duration of labour (AOR: 7.18; 95% CI: 2.73, 18.90; P = 0.01), vaginal or cervical lacerations (AOR: 4.95; 95% CI: 2.49, 9.86; P = 0.01), instrumental (forceps or vacuum)-assisted birth (AOR: 2.92; 95% CI: 1.25, 6.81; P = 0.01), retained placenta (AOR: 21.83; 95% CI: 6.33, 75.20; P = 0.01), antepartum haemorrhage in recent pregnancy (AOR: 6.90; 95% CI: 3.43, 13. 84; p = 0.01), women in labour referred from primary health centres (AOR: 2.48; 95% CI: 1.39, 4.42; P = 0.02), and births managed by medical interns (AOR: 2.90; 95% CI: 1.55, 5.37; P = 0.01).

CONCLUSION

We found that while the incidence of primary postpartum haemorrhage appeared to be lower than in other studies in Africa the associated maternal mortality was higher. Although most factors associated with primary postpartum haemorrhage were consistent with those identified in the literature, two additional specific factors, were found to be prevalent among women in Ethiopia; the factors were referred women in labour from primary health facilities and births managed by medical interns. Maternal healthcare providers in these hospitals require training on the management of a birthing emergency.

Machine learning-based prediction of postpartum hemorrhage after vaginal delivery: combining bleeding high risk factors and uterine contraction curve

PURPOSE

This work used a machine learning model to improve the accuracy of predicting postpartum hemorrhage in vaginal delivery.

METHODS

Among the 25,098 deliveries in the obstetrics department of the First Hospital of Jinan University recorded from 2016 to 2020, 10,520 were vaginal deliveries with complete study data. Further review selected 850 cases of postpartum hemorrhage (amount of bleeding > 500 mL) and 54 cases of severe postpartum hemorrhage (amount of bleeding > 1000 mL). Indicators of clinical risk factors for postpartum hemorrhage were retrieved from electronic medical records. Features of the uterine contraction curve were extracted 2 h prior to vaginal delivery and modeled using a 49-variable machine learning with 90% of study cases used in the training set and 10% of study cases used in the test set. Accuracy was compared among the assessment table, classical statistical models, and machine learning models used to predict postpartum hemorrhage to assess their clinical use. The assessment table contained 16 high-risk factor scores to predict postpartum hemorrhage. The classical statistical model used was Logistic Regression (LR). The machine learning models were Random Forest (RF), K Nearest Neighbor (KNN), and the one integrated with Lightgbm (LGB) and LR. The effect of model prediction was evaluated by area under the receiver operating characteristic curve (AUC), namely, C-static, calibration curve Brier score, decision curve, F-measure, sensitivity (SE), and specificity (SP).

RESULTS

1: Among the tested tools, the machine learning model LGB + LR has the best performance in predicting postpartum hemorrhage. Its Brier, AUC, and F-measure scores are better than those of other models in each group, and its SE and SP reach 0.694 and 0.800, respectively. The predictive performance of the classical statistical model LR is AUC: 0.729, 95%CI [0.702-0.756]). 2: Verification on the testing set reveals that the features of uterine contraction contribute to the improved accuracy of the model prediction. 3: LGB + LR model suggested that among the 49 indicators for predicting severe postpartum hemorrhage, the importance of the first 10 characteristics in descending order is as follows: hematocrit (%), shock index, frequency of contractions (min-1), white blood cell count, gestational hypertension, neonatal weight (kg), time of second labor (min), mean area of contractions (mmHg s), total amniotic fluid (mL), and body mass index (BMI). The prediction effect is close to that of the model after training with all 49 features. The predictive effect was close to that of the model after training using all 49 features. 4: Contraction frequency and intensity Mean_Area (representing effective contractions) have a high predictive value for severe postpartum hemorrhage. 5: Blood loss amount within 2 h has a high warning effect on postpartum hemorrhage, and the increase in AUC to 0.95 indicates that postpartum bleeding mostly occurs within 2 h after delivery.

CONCLUSION

Machine learning models incorporated with uterine contraction features can further improve the accuracy of postpartum hemorrhage prediction in vaginal delivery and provide a reference for clinicians to intervene early and reduce adverse pregnancy outcomes.

Place of birth and outcomes associated with large volume transfusion: an observational study

BACKGROUND

Guidelines recommend that women at high risk of postpartum haemorrhage deliver at facilities able to handle heavy bleeding. However postpartum haemorrhage is often unexpected. This study aims to compare outcomes and health service use related to transfusion of ≥4 units of red blood cells between women delivering in tertiary and lower level hospitals.

METHODS

The study population was women giving birth in public hospitals in New South Wales, Australia, between July 2006 and December 2010. Data were obtained from linked hospital, birth and blood bank databases. The exposure of interest was transfusion of four or more units of red cells during admission for delivery. Outcomes included maternal morbidity, length of stay, neonatal morbidity and need for other blood products or transfer to higher care. Multivariable regression models were developed to predict need of transfusion of ≥4 units of red cells using variables known early in pregnancy and those known by the birth admission.

RESULTS

Data were available for 231,603 births, of which 4309 involved a blood transfusion, with 1011 (0.4%) receiving 4 or more units. Women giving birth in lower level and/or smaller hospitals were more likely to receive ≥4 units of red cells. Women receiving ≥4 units in tertiary settings were more likely to receive other blood products and have longer hospital stays, but morbidity, readmission and hysterectomy rates were similar. Although 46% of women had no identifiable risk factors early in pregnancy, 20% of transfusions of ≥4 units occurred within this group. By the birth admission 70% of women had at least one risk factor for requiring ≥4 units of red cells.

CONCLUSIONS

Overall outcomes for women receiving ≥4 units of red cells were comparable between tertiary and non-tertiary facilities. This is important given the inability of known risk factors to predict many instances of postpartum haemorrhage.

Development and validation of a prediction model for postpartum hemorrhage at a single safety net tertiary care center

BACKGROUND

Postpartum hemorrhage is a leading cause of pregnancy-related morbidity and mortality; however, there is limited ability to identify women at risk of this obstetrical complication.

OBJECTIVE

This study aimed to develop and validate a prediction model for postpartum hemorrhage based on antenatal and intrapartum risk factors.

STUDY DESIGN

This was a retrospective cohort study of women who delivered between April 2016 and March 2019 at a single safety net hospital. The prevalence of postpartum hemorrhage, defined as blood loss of ≥1000 mL at the time of delivery, was determined, and characteristics were compared between women with and without postpartum hemorrhage. Women were randomly assigned to a prediction or a validation cohort. The selection of predictors to be included in the model was based on known antenatal and intrapartum risk factors for postpartum hemorrhage. A multivariable logistic regression with a backward stepwise approach was used to create a prediction model. Area under the receiver operating characteristic curve and 95% bootstrap confidence intervals were calculated. Using the final model, a single threshold for classifying postpartum hemorrhage was chosen, and the resulting sensitivity, specificity, and false-negative and false-positive rates were explored.

RESULTS

The prevalence rates of postpartum hemorrhage in the prediction and validation cohorts were 6.3% (377 of 6000 cases) and 6.4% (241 of 3774 cases), respectively (P=.83). The following predictors were selected for the final model: maternal body mass index (kg/m²), number of fetuses, history of postpartum hemorrhage, admission platelets of <100,000/µL, chorioamnionitis, arrest of descent, placental abruption, and active labor duration. The predictive model had an area under the receiver operating characteristic curve of 0.82 (95% confidence interval, 0.81-0.84). When applied to the validation cohort, the model had an area under the receiver operating characteristic curve of 0.81 (95% confidence interval, 0.78-0.83), a sensitivity of 86.9%, a specificity of 74.2%, a positive predictive value of 18.6%, a negative predictive value of 98.8%, a false-negative rate of 13.1%, and a false-positive rate of 25.9%.

CONCLUSION

The model performed reasonably well in identifying women at risk of postpartum hemorrhage. Further studies are necessary to evaluate the model in clinical practice and its effect on decreasing the prevalence of postpartum hemorrhage and associated maternal morbidity.

Using shear wave elastography to assess uterine tonicity after vaginal delivery

This study aims to evaluate the feasibility and clinical interest of shear wave elastography, by quantitatively estimating the baseline stiffness of the myometrium before and after placental expulsion. We conducted a prospective cohort study of women at term, without known risk factors for postpartum hemorrhage, who gave birth via spontaneous labor in our tertiary center. Myometrium tonicity was evaluated based on measurements of shear wave speed (SWS) in the anterior uterine corpus. All data points were collected by a single operator. Measurements were carried out at three different time points: after fetal delivery (T1), after placental delivery (T2) and 30 min after placental delivery (T3). Our primary objective was to assess the feasibility of this new imaging technique. Ten valid SWS measurements obtained at each of the three different time points were considered as a positive primary outcome. Our secondary objectives were to evaluate the difference in median myometrial shear wave velocity between each time point, as well as to determine the correlation between myometrial shear wave velocity and patients’ characteristics. 38 women were recruited during the study period, of whom 34 met the study criteria. 1017 SWS measurements were obtained. The median time to perform measurements was 16 s for one value, and 2 min 56 s for ten. For 11 women (32%) it was not possible to achieve ten SWS at T1 as placental expulsion immediately followed the birth of the newborn. One patient experienced placental retention and only measurements at T1 were performed. For all other patients, we were successfully able to obtain all measures as intended. There was no difference in the mean shear wave speed between the three time points. After adjustments for confounders, we observed a significant correlation for total blood loss (correlation coefficient = − 0.26, p < 0.001, units of oxytocin (correlation coefficient = − 0.34, p = 0.03), and newborn weight (correlation coefficient = − 0.08, p = 0.001). It is feasible to assess uterine tonicity by shear wave imaging, after placental expulsion. We did not observe a variance in uterine tonicity between the three time points. Women who had higher blood loss, received more units of oxytocin and/or those with newborns of a higher weight exhibited lower shear wave speed measures.

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.

Improvements and limitations in developing multivariate models of hemorrhage and transfusion risk for the obstetric population

BACKGROUND

Maternal hemorrhage protocols involve risk screening. These protocols prepare clinicians for potential hemorrhage and transfusion in individual patients. Patient-specific estimation and stratification of risk may improve maternal outcomes.

STUDY DESIGN AND METHODS

Prediction models for hemorrhage and transfusion were trained and tested in a data set of 74 variables from 63 973 deliveries (97.6% of the source population of 65 560 deliveries included in a perinatal database from an academic urban delivery center) with sufficient data at pertinent time points: antepartum, peripartum, and postpartum. Hemorrhage and transfusion were present in 6% and 1.6% of deliveries, respectively. Model performance was evaluated with the receiver operating characteristic (ROC), precision-recall curves, and the Hosmer-Lemeshow calibration statistic.

RESULTS

For hemorrhage risk prediction, logistic regression model discrimination showed ROCs of 0.633, 0.643, and 0.661 for the antepartum, peripartum, and postpartum models, respectively. These improve upon the California Maternal Quality Care Collaborative (CMQCC) accuracy of 0.613 for hemorrhage. Predictions of transfusion resulted in ROCs of 0.806, 0.822, and 0.854 for the antepartum, peripartum, and postpartum models, respectively. Previously described and new risk factors were identified. Models were not well calibrated with Hosmer-Lemeshow statistic P values between .001 and .6.

CONCLUSIONS

Our models improve on existing risk assessment; however, further enhancement might require the inclusion of more granular, dynamic data. With the goal of increasing translatability, this work was distilled to an online open-source repository, including a form allowing risk factor inputs and outputs of CMQCC risk, alongside our numerical risk estimation and stratification of hemorrhage and transfusion.

Machine Learning and Statistical Models to Predict Postpartum Hemorrhage

OBJECTIVE

To predict a woman's risk of postpartum hemorrhage at labor admission using machine learning and statistical models.

METHODS

Predictive models were constructed and compared using data from 10 of 12 sites in the U.S. Consortium for Safe Labor Study (2002-2008) that consistently reported estimated blood loss at delivery. The outcome was postpartum hemorrhage, defined as an estimated blood loss at least 1,000 mL. Fifty-five candidate risk factors routinely available on labor admission were considered. We used logistic regression with and without lasso regularization (lasso regression) as the two statistical models, and random forest and extreme gradient boosting as the two machine learning models to predict postpartum hemorrhage. Model performance was measured by C statistics (ie, concordance index), calibration, and decision curves. Models were constructed from the first phase (2002-2006) and externally validated (ie, temporally) in the second phase (2007-2008). Further validation was performed combining both temporal and site-specific validation.

RESULTS

Of the 152,279 assessed births, 7,279 (4.8%, 95% CI 4.7-4.9) had postpartum hemorrhage. All models had good-to-excellent discrimination. The extreme gradient boosting model had the best discriminative ability to predict postpartum hemorrhage (C statistic: 0.93; 95% CI 0.92-0.93), followed by random forest (C statistic: 0.92; 95% CI 0.91-0.92). The lasso regression model (C statistic: 0.87; 95% CI 0.86-0.88) and logistic regression (C statistic: 0.87; 95% CI 0.86-0.87) had lower-but-good discriminative ability. The above results held with validation across both time and sites. Decision curve analysis demonstrated that, although all models provided superior net benefit when clinical decision thresholds were between 0% and 80% predicted risk, the extreme gradient boosting model provided the greatest net benefit.

CONCLUSION

Postpartum hemorrhage on labor admission can be predicted with excellent discriminative ability using machine learning and statistical models. Further clinical application is needed, which may assist health care providers to be prepared and triage at-risk women.

Can prepartum platelet indices be a parameter to predict postpartum hemorrhage?

OBJECTIVE

Postpartum hemorrhage (PPH) is the single largest contributor to maternal mortality worldwide. It has been demonstrated that certain platelet parameters are indicative of platelet reactivity. The aim of this study was to determine whether antenatal platelet indices can be used as risk factors in the prediction of primary PPH.

METHODS

This comparative case-control study involved 3207 pregnant women at term who were recruited over one year period in İstanbul. Postpartum hemorrhage, defined as blood loss ≥1000 mL within 24 h after delivery. The study group consisted of 42 patients who developed primary PPH after vaginal delivery without defined risk factors. The patients in the control group were matched with age, parity, body mass index (BMI), and hemoglobin value. Platelet indices - platelet count, mean platelet volume (MPV), platelet distribution width, and plateletcrit were measured prior to delivery and evaluated for the prediction of PPH.

RESULTS

Prepartum MPV and PDW values were determined to be lower in the patients with in the PPH group, when compared to the healthy group (respectively, p < .001 and p < .004). By receiver-operating characteristic analysis, MPV and PDW were able to distinguish between patients with and without any bleeding (respectively, AUC 0.823, 95% confidence interval (CI) 0.735-0.912, (AUC) 0.682, 95% CI 0.569-0.795). Prepartum MPV (cutoff = 10.95 fL) had a high AUC (>0.8) for predicting PPH, with a specificity of 81% and sensitivity of 69%.

CONCLUSION

Results suggest a novel hypothesis that pre-delivery lower MPV value may be used predicting PPH.

FREQUENCY, DISTRIBUTION BY PLACE OF DELIVERY AND PARITY, CAUSES, MANAGEMENT OPTIONS AND OUTCOME OF PRIMARY POSTPARTUM HAEMORRHAGE IN POSTPARTUM WOMEN OF DISTRICT PESHAWAR, PAKISTAN

Background: Primary postpartum haemorrhage (PPPH) is the leading cause of maternal morbidity and mortality in low resource countries like Pakistan. The objectives of this study were to determine the frequency, distribution by place of delivery and parity, causes, management options and outcome of PPPH in postpartum women of District Peshawar, Pakistan. Materials & Methods: This cross-sectional study was conducted in Department of Gynaecology & Obstetrics, Lady Reading Hospital, Peshawar, Pakistan from 1st January 2019 to 30th June 2019. Sample size of 4,034 was with 0.39342 % margin of error, 95% confidence level, prevalence of PPPH 2% and a population of 23,607 postpartum women. All postpartum women were eligible. Those with secondary PPH, surgical management for PPPH done at some other hospital, with known bleeding disorders and on anticoagulants were excluded. All these patients were managed according to standard protocols. Data was collected for following variables; presence of PPPH (yes/ no), place of delivery (in-hospital deliveries/ referred cases), parity (primipara/multipara/grandmultipara), causes of PPPH (uterus atony/retained placenta-RPOC/ruptured uterus/genital tract tears), management options of PPPH (conservative management/laparotomy with repair of ruptured uterus/laparotomy with uterine artery ligation and B-Lynch/repair of genital tract tears other than ruptured uterus/removal of retained placenta & RPOC/hysterectomy) and outcome of PPPH (uneventful recovery/maternal near miss/maternal mortality). Frequencies and percentages with confidence intervals were calculated for these variables. Results: Out of 4034 postpartum women, frequency of PPPH was 400 (9.92%). Out of 4034 women, distribution of 400 cases of PPPH by place of delivery was 222 (5.50%) in-hospital deliveries and 178 (4.42%) referred cases and by parity it was primipara 79 (1.96%), multipara 243 (6.03%) and grandmultipara 78 (1.93%) cases. Out of 400 cases of PPPH, frequency of uterine atony was 254 (63.50%) and conservative management 245 (61.25%). Out of 400 cases, frequency of uneventful recovery was 352 (88%), maternal near miss 40 (10%) and maternal mortality eight (2%) cases. Conclusion: Primary postpartum haemorrhage (PPPH) continues to be a common and serious complication of delivery with uterine atony being its most predominant cause.

Prognostic models for adverse pregnancy outcomes in low-income and middle-income countries: a systematic review

INTRODUCTION

Ninety-nine per cent of all maternal and neonatal deaths occur in low-income and middle-income countries (LMIC). Prognostic models can provide standardised risk assessment to guide clinical management and can be vital to reduce and prevent maternal and perinatal mortality and morbidity. This review provides a comprehensive summary of prognostic models for adverse maternal and perinatal outcomes developed and/or validated in LMIC.

METHODS

A systematic search in four databases (PubMed/Medline, EMBASE, Global Health Library and The Cochrane Library) was conducted from inception (1970) up to 2 May 2018. Risk of bias was assessed with the PROBAST tool and narratively summarised.

RESULTS

1741 articles were screened and 21 prognostic models identified. Seventeen models focused on maternal outcomes and four on perinatal outcomes, of which hypertensive disorders of pregnancy (n=9) and perinatal death including stillbirth (n=4) was most reported. Only one model was externally validated. Thirty different predictors were used to develop the models. Risk of bias varied across studies, with the item 'quality of analysis' performing the least.

CONCLUSION

Prognostic models can be easy to use, informative and low cost with great potential to improve maternal and neonatal health in LMIC settings. However, the number of prognostic models developed or validated in LMIC settings is low and mirrors the 10/90 gap in which only 10% of resources are dedicated to 90% of the global disease burden. External validation of existing models developed in both LMIC and high-income countries instead of developing new models should be encouraged.

PROSPERO REGISTRATION NUMBER

CRD42017058044.

Postpartum hemorrhage: new insights for definition and diagnosis

The current definition of is inadequate for early recognition of this important cause of maternal death that is responsible for >80,000 deaths worldwide in 2015. A stronger definition of postpartum hemorrhage should include both blood loss and clinical signs of cardiovascular changes after delivery, which would help providers to identify postpartum hemorrhage more promptly and accurately. Along with the amount of blood loss, clinical signs, and specifically the shock index (heart rate divided by systolic blood pressure) appear to aid in more accurate diagnosis of postpartum hemorrhage.

Blood Transfusion Practices in Obstetrics: Our Experience

OBJECTIVES

To ascertain and analyze the indications for transfusion of blood components in obstetric practice at our center.

MATERIALS AND METHODS

A prospective observational study was conducted to analyze the various indications for transfusion of blood components in a tertiary care hospital.

RESULTS

1.3% of all obstetric patients from our center had blood components transfusion during the study period. Postpartum hemorrhage, placental causes and anemia are the commonest causes for need of transfusion in obstetric practice.

Risk factors for self-reported postpartum hemorrhage in Ga East, Ghana

OBJECTIVE

To document the prevalence of self-reported postpartum hemorrhage (PPH) in Ga East, Accra, Ghana, and examine the demographic, biological, and social risk factors for PPH.

METHODS

The present study was a cross-sectional secondary analysis of data collected during 2010-2012 from the Ghana Essential Health Interventions Program, a quasi-experimental interventional study surveying households in the urban Ga East Municipal District. The analysis included data from randomly selected parous women of childbearing age (15-49 years), excluding those with a history of abortion (spontaneous or induced) or stillbirth. The χ² test and logistic regression were used to identify significant risk factors for self-reported PPH.

RESULTS

The current analysis included 2136 women. Self-reported PPH was recorded for 95 (4.4%) participants. The maternal age at delivery, the duration of labor, and the number of skilled delivery providers were significantly associated with self-reported PPH. Prolonged labor (odds ratio 3.70, 95% confidence interval 2.27-5.94; P<0.001) and maternal age (odds ratio 0.96, 95% confidence interval 0.94-0.99; P=0.020) were predictors of self-reported PPH.

CONCLUSION

Prolonged labor and younger maternal age were related to a higher burden of reported PPH. These findings were congruent with global and regional data on the prevalence and risk factors for objectively measured PPH and could help focus intervention strategies to high-risk groups, particularly in resource-limited settings.

Misoprostol for the prevention of postpartum hemorrhage during home births in rural Lao PDR: establishing a pilot program for community distribution

PURPOSE

The purpose of this study was to gather the necessary data to support the design and implementation of a pilot program for women who are unable to deliver in a healthcare facility in the Lao People's Democratic Republic (PDR), by using community distribution of misoprostol to prevent postpartum hemorrhage (PPH). The study builds on an earlier research that demonstrated both support and need for community-based distribution of misoprostol in Lao PDR.

METHODS

This qualitative study identified acceptability of misoprostol and healthcare system needs at varying levels to effectively distribute misoprostol to women with limited access to facility-based birthing. Interviews (n=25) were undertaken with stakeholders at the central, provincial, and district levels and with community members in five rural communities in Oudomxay, a province with high rates of maternal mortality. Focus group discussions (n=5) were undertaken in each community.

RESULTS

Respondents agreed that PPH was the major cause of preventable maternal mortality with community distribution of misoprostol an acceptable and feasible interim preventative solution. Strong leadership, training, and community mobilization were identified as critical success factors. While several participants preferred midwives to distribute misoprostol, given the limited availability of midwives, there was a general agreement that village health workers or other lower level workers could safely administer misoprostol. Many key stakeholders, including women themselves, considered that these community-level staff may be able to provide misoprostol to women for self-administration, as long as appropriate education on its use was included. The collected data also helped identify appropriate educational messages and key indicators for monitoring and evaluation for a pilot program.

CONCLUSION

The findings strengthen the case for a pilot program of community distribution of misoprostol to prevent PPH in remote communities where women have limited access to a health facility and highlight the key areas of consideration in developing such a program.

Midwives Utilization of Life Saving Skills for Prevention and Management of Hemorrhage in Primary Health Centers in Anambra State, Nigeria

In Nigeria, 58,000 women die annually of complications of pregnancy and childbirth. Of these deaths, 23.73% are caused by obstetric hemorrhage, which can be prevented with life saving skills (LSS), an early, aggressive, and coordinated intervention for prevention and management of hemorrhage. This study assessed the midwives’ knowledge and practice of LSS among 177 Nigerian midwives at 126 primary health centers. Data were collected using a self-administered questionnaire and observation checklist. Finding indicated 52.5% of the midwives were highly knowledgeable about LSS. However, although 70.6% self-reported a high level of implementing LSS procedures, only 21.7% of the midwives observed actually demonstrated a high level of implementation. The majority practiced some LSS components, including early clamping and cutting the cord (95%) and uterine massage (73.3%); all administered oxytocin, most frequently when delivering the anterior shoulders. The midwives reported numerous challenges to implementing LSS, including lack of an assistant when on duty (23.7%) and shortage of oxytocin (20.3%). These limitations were confirmed by on-site observation in which 66.7% were the sole midwife on duty and 23.3% had no assistant available. A positive relationship was found between midwives’ knowledge and practice, with knowledge varying by academic qualifications. However, practice patterns did not differ by years of experience. These findings indicate a gap exists between the midwives’ actual practice and evidence-based practice standard. Therefore, continuous training, frequent monitoring, and supervision are necessary to improve regular implementation of LSS in practice.

Excessive bleeding is a normal cleansing process: a qualitative study of postpartum haemorrhage among rural Uganda women

Background

Postpartum haemorrhage (PPH) remains the leading cause of maternal morbidity and mortality worldwide. The main strategy for preventing PPH is the use of uterotonic drugs given prophylactically by skilled health workers. However, in settings where many women still deliver at home without skilled attendants, uterotonics are often inaccessible. In such cases, women and their caregivers need to recognize PPH promptly so, as to seek expert care. For this reason, it is important to understand how women and their caregivers recognize PPH, as well as the actions they undertake to prevent and treat PPH in home births. Such knowledge can also inform programs aiming to make uterotonics accessible at the community level.

Methods

Between April and June 2012, a phenomenological study was carried out in a rural Ugandan district involving 15 in-depth interviews. Respondents were purposively sampled and included six women who had delivered at home in the past year and nine traditional birth attendants (TBAs). The interviews explored how PPH was recognized, its perceived causes, and the practices that respondents used in order to prevent or treat it. Phenomenological descriptive methodology was used to analyse the data.

Results

Bleeding after childbirth was considered to be a normal cleansing process, which if stopped or inhibited would lead to negative health consequences to the mother. Respondents used a range of criteria to recognize PPH: rate of blood flow, amount of blood (equivalent to two clenched fists), fainting, feeling thirsty, collapsing or losing consciousness immediately after birth. As a group, respondents seemed to correctly identify women at risk of PPH (those with twin pregnancies, high parity or prolonged labour), but many individuals did not know all the reasons. Respondents used cold drink, uterine massage and traditional medicine to treat PPH.

Conclusion

The community viewed bleeding after childbirth as a normal process and their methods of determining excessive bleeding are imprecise and varied. This opens the door for intervention for reducing delays in the home diagnosis of PPH. This includes increasing awareness among TBAs, women and their families about the risk of death due to excessive bleeding in the immediate postpartum period.

Laboratory prediction of primary postpartum haemorrhage: a comparative cohort study

BACKGROUND

Postpartum haemorrhage (PPH) is the leading cause of maternal deaths, the world over. The aim of this study was to determine laboratory parameters that could serve as risk factors for primary PPH.

METHODS

This comparative cohort study involved 350 pregnant women at term who were recruited consecutively from the Komfo Anokye Teaching Hospital, Kumasi, Ghana. PPH was defined as a measured blood loss ≥ 500 ml or enough to cause haemodynamic shock. Basic demographic data was gathered and blood was collected for laboratory assays before delivery. Univariate and multivariate logistic regression models were used to identify variables that were significantly associated with primary PPH.

RESULTS

Of the total recruited study participants (350), five declined to participate and 74 went through caesarean section, episiotomy or instrumental deliveries and were excluded. Of the remaining (271) study participants who went through spontaneous vaginal delivery, fifty five (55) were diagnosed with primary PPH (Group 1) and the remaining 216 were those who did not have PPH (Group 2). Demographic characteristics did not differ between the two groups (P > 0.05). Univariate analysis showed that AST (P = 0.043), urea (P < 0.001), creatinine (P = 0.002), urea-to-creatinine ratio (P = 0.014) and the proportion of abnormal peripheral blood smear (P < 0.001) was higher among women in Group 1 compared to those in Group 2. Women in Group 1 had a significantly lower haemoglobin concentration (10.7 g/dL) compared to those in Group 2 (12.1g/dL). Upon multivariate analysis, an abnormal peripheral blood smear (AOR = 2.9672), Hb, (AOR = 0.5791), moderate to severe anaemia (Hb <10 g/dL) (AOR = 3.1385), Urea (AOR = 3.6435) and intra-renal azotaemia (AOR = 0.1893) remained significant.

CONCLUSION

Many laboratory parameters are associated with primary PPH but only a few are independent risk factors. A total clinical work-up including laboratory evaluation of the independent blood variables identified in this study will help a great deal to identify individuals at high risk for PPH.

Prognostic models in obstetrics: available, but far from applicable

Health care provision is increasingly focused on the prediction of patients' individual risk for developing a particular health outcome in planning further tests and treatments. There has been a steady increase in the development and publication of prognostic models for various maternal and fetal outcomes in obstetrics. We undertook a systematic review to give an overview of the current status of available prognostic models in obstetrics in the context of their potential advantages and the process of developing and validating models. Important aspects to consider when assessing a prognostic model are discussed and recommendations on how to proceed on this within the obstetric domain are given. We searched MEDLINE (up to July 2012) for articles developing prognostic models in obstetrics. We identified 177 papers that reported the development of 263 prognostic models for 40 different outcomes. The most frequently predicted outcomes were preeclampsia (n = 69), preterm delivery (n = 63), mode of delivery (n = 22), gestational hypertension (n = 11), and small-for-gestational-age infants (n = 10). The performance of newer models was generally not better than that of older models predicting the same outcome. The most important measures of predictive accuracy (ie, a model's discrimination and calibration) were often (82.9%, 218/263) not both assessed. Very few developed models were validated in data other than the development data (8.7%, 23/263). Only two-thirds of the papers (62.4%, 164/263) presented the model such that validation in other populations was possible, and the clinical applicability was discussed in only 11.0% (29/263). The impact of developed models on clinical practice was unknown. We identified a large number of prognostic models in obstetrics, but there is relatively little evidence about their performance, impact, and usefulness in clinical practice so that at this point, clinical implementation cannot be recommended. New efforts should be directed toward evaluating the performance and impact of the existing models.

Calibrated delivery drape versus indirect gravimetric technique for the measurement of blood loss after delivery: a randomized trial

Background

Trials of interventions for PPH prevention and treatment rely on different measurement methods for the quantification of blood loss and identification of PPH. This study’s objective was to compare measures of blood loss obtained from two different measurement protocols frequently used in studies.

Methods

Nine hundred women presenting for vaginal delivery were randomized to a direct method (a calibrated delivery drape) or an indirect method (a shallow bedpan placed below the buttocks and weighing the collected blood and blood-soaked gauze/pads). Blood loss was measured from immediately after delivery for at least one hour or until active bleeding stopped.

Results

Significantly greater mean blood loss was recorded by the direct than by the indirect measurement technique (253.9 mL and 195.3 mL, respectively; difference = 58.6 mL (95% CI: 31–86); p < 0.001). Almost twice as many women in the direct than in the indirect group measured blood loss > 500 mL (8.7% vs. 4.7%, p = 0.02).

Conclusions

The study suggests a real and significant difference in blood loss measurement between these methods. Research using blood loss measurement as an endpoint needs to be interpreted taking measurement technique into consideration.

Trial registration

This study has been registered at clinicaltrials.gov as NCT01885845.

Modeling maternal mortality in Bangladesh: the role of misoprostol in postpartum hemorrhage prevention

BACKGROUND

Bangladesh is one of the few countries that may actually achieve the fifth Millennium Development Goal (MDG) in time, despite skilled birth attendance remaining low. The purpose of this paper is to examine the potential role misoprostol can play in the decline of maternal deaths attributed to postpartum hemorrhage (PPH) in Bangladesh.

METHODS

Using data from a misoprostol and blood loss measurement tool feasibility study in Bangladesh, observed cause specific maternal mortality ratios (MMRs) were estimated and contrasted with expected ratios using estimates from the Bangladesh Maternal Mortality Survey (BMMS) data. Using Crystal Ball 7 we employ Monte Carlo simulation techniques to estimate maternal deaths in four scenarios, each with different levels of misoprostol coverage. These scenarios include project level misoprostol coverage (69%), no (0%), low (40%), and high (80%) misoprostol coverage. Data on receipt of clean delivery kit, use of misoprostol, experience of PPH, and cause of death were used in model assumptions.

RESULTS

Using project level misoprostol coverage (69%), the mean number of PPH deaths expected was 40 (standard deviation = 8.01) per 100,000 live births. Assuming no misoprostol coverage (0%), the mean number of PPH deaths expected was 51 (standard deviation = 9.30) per 100,000 live births. For low misoprostol coverage (40%), the mean number of PPH deaths expected was 45 (standard deviation = 8.26) per 100,000 live births, and for high misoprostol coverage (80%), the mean number of PPH deaths expected was 38 (standard deviation = 7.04) per 100,000 live births.

CONCLUSION

This theoretical exercise hypothesizes that prophylactic use of misoprostol at home births may contribute to a reduction in the risk of death due to PPH, in addition to reducing the incidence of PPH. If findings from this modeling exercise are accurate and uterotonics can prevent maternal death, misoprostol could be the tool countries need to further reduce maternal mortality at home births.

Is attendant at delivery associated with the use of interventions to prevent postpartum hemorrhage at home births? The case of Bangladesh

BACKGROUND

Hemorrhage is the leading cause of maternal mortality in Bangladesh, the majority of which is due to postpartum hemorrhage (PPH), blood loss of 500 mL or more. Many deaths due to PPH occur at home where approximately 77% of births take place. This paper aims to determine whether the attendant at home delivery (i.e. traditional birth attendant (TBA) trained on PPH interventions, TBA not trained on interventions, or lay attendant) is associated with the use of interventions to prevent PPH at home births.

METHODS

Data come from operations research to determine the safety, feasibility, and acceptability of scaling-up community-based provision of misoprostol and an absorbent delivery mat in rural Bangladesh. Analyses were done using data from antenatal care (ANC) cards of women who delivered at home without a skilled attendant (N =66,489). Multivariate logistic regression was used to assess the likelihood of using the interventions.

RESULTS

Overall, 67% of women who delivered at home without a skilled provider used misoprostol and the delivery mat (the interventions). Women who delivered at home and had a trained TBA present had 2.72 (95% confidence interval, 2.15-3.43) times the odds of using the interventions compared to those who had a lay person present. With each additional ANC visit (maximum of 4) a woman attended, the odds of using the interventions increased 2.76 times (95% confidence interval, 2.71-2.81). Other sociodemographic variables positively associated with use of the interventions were age, secondary or higher education, and having had a previous birth.

CONCLUSION

Findings indicate that trained TBAs can have a significant impact on utilization of interventions to prevent PPH in home births. ANC visits can be an important point of contact for knowledge transfer and message reinforcement about PPH prevention.

Prevention of postpartum hemorrhage in low-resource settings: current perspectives

BACKGROUND

Postpartum hemorrhage (PPH) is the leading cause of maternal death in low-income countries and is the primary cause of approximately one-quarter of global maternal deaths. The purpose of this paper is to provide a review of PPH prevention interventions, with a particular focus on misoprostol, and the challenges and opportunities that preventing PPH in low-resource settings presents.

METHODS

Using PubMed, we conducted a review of the literature on the randomized controlled trials of interventions to prevent PPH. We then searched PubMed and Google Scholar for nonrandomized field trials of interventions to prevent PPH. We limited our review to interventions that are discussed in the current World Health Organization (WHO) recommendations for PPH prevention and present evidence regarding the use of these interventions. We focused our review on nondrug PPH prevention interventions compared with no intervention and uterotonics versus placebo; this review does not decipher the relative effectiveness of uterotonic drugs. We describe challenges to and opportunities for scaling up PPH prevention interventions.

RESULTS

Active management of the third stage of labor is considered the "gold standard" strategy for reducing the incidence of PPH. It combines nondrug interventions (controlled cord traction and cord clamping) with the administration of an uterotonic drug, the preferred uterotonic being oxytocin. Unfortunately, oxytocin has limited application in resource-poor countries, due to its heat instability and required administration by a skilled provider. New heat-stable drugs and drug formulations are currently in development that may improve the prevention of PPH; however, misoprostol is a viable option for provision at home by a lay health care worker or the woman herself, in the interim.

CONCLUSION

As the main cause of maternal mortality worldwide, PPH prevention interventions need to be prioritized. Increased access to prophylactic uterotonics, regardless of where deliveries occur, should be the primary means of reducing the burden of this complication.

Inflammatory and procoagulant cytokine levels during pregnancy as predictors of adverse obstetrical complications

INTRODUCTION

Disturbances in cytokine networks are believed to be associated with increased risk of adverse pregnancy complications.

METHODS

Plasma samples collected from pregnant women with preterm deliveries, high-risk pregnancy complications including postpartum hemorrhage, hypertensive disorders, and multiple gestations, and normal pregnancies were analyzed at different periods throughout gestation and postpartum. Interleukin (IL) 1β , IL-6, IL-8, IL-10, tumor necrosis factor α, and antiprotein Z antibody levels were measured by enzyme-linked immunosorbent assay.

RESULTS

The IL-6 levels in preterm delivery patients were elevated during pregnancy with statistically significant differences observed at 21 to 32 weeks (P < .01) and 33+ weeks (P < .001). The IL-10 levels were increased in normal pregnancy at all time points compared to the other patient groups (P < .05). The TNF-α levels were elevated in the high-risk pregnancy group versus normal controls (P < .001 at <21 weeks and P < .05 at 21-32 weeks).

CONCLUSION

Analysis of the maternal plasma for elevated IL-6 and reduced IL-10 levels may be of value in the early prediction of pregnancy complications.

Striving for scientific stringency: a re-analysis of a randomised controlled trial considering first-time mothers' obstetric outcomes in relation to birth position

Background

The aim of this study was to compare maternal labour and birth outcomes between women who gave birth on a birth seat or in any other position for vaginal birth and further, to study the relationship between synthetic oxytocin augmentation and maternal blood loss, in a stratified sample.

Methods

A re-analysis of a randomized controlled trial in Sweden. An on-treatment analysis was used to study obstetrical outcomes for nulliparous women who gave birth on a birth seat (birth seat group) compared to birth in any other position for vaginal birth (control group). Data were collected between November 2006 and July 2009. The outcome measurements included perineal outcome, post partum blood loss, epidural analgesia, synthetic oxytocin augmentation and duration of labour.

Results

The major findings of this paper were that women giving birth on the birth seat had shorter duration of labour and were significantly less likely to receive synthetic oxytocin for augmentation in the second stage of labour. Significantly more women had an increased blood loss when giving birth on the birth seat, but had no difference in perineal outcomes. Blood loss was increased regardless of birth position if women had been exposed to synthetic oxytocin augmentation during the first stage of labour.

Conclusions

The results of this analysis imply that women with a straightforward birth process may well benefit from giving birth on a birth seat without risk for any adverse obstetrical outcomes. However it is important to bear in mind that, women who received synthetic oxytocin during the first stage of labour may have an increased risk for greater blood loss when giving birth on a birth seat. Finally it is of vital importance to scrutinize the influence of synthetic oxytocin administered during the first stage of labour on blood loss postpartum, since excessive blood loss is a well-documented cause of maternal mortality worldwide and may cause severe maternal morbidity in high-income countries.

Trial registration

Unique Protocol ID: NCT01182038 ( http://register.clinicaltrials.gov)