The Epidemiology of Postpartum Hemorrhage in a Large, Nationwide Sample of Deliveries

Risk factors for early postpartum hemorrhage: A retrospective, population-based, cohort analysis

OBJECTIVE

To identify risk factors for developing early postpartum hemorrhage (PPH) and to examine whether risk factors vary according to severity and mode of delivery.

METHODS

A population-based cohort study was conducted in which all deliveries at a tertiary medical center were included. Risk factors for developing early PPH were compared based on the severity of bleeding as well as the mode of delivery. Multiple logistic regression models were used to control for confounders.

RESULTS

Among 322 497 deliveries included in the analysis, early PPH complicated 1811 (0.56%) of all deliveries. Among all cases of early PPH, 505 deliveries (28%) were complicated with severe PPH. Using a logistic regression model, in vitro fertilization (IVF) pregnancy, previous cesarean delivery (CD), pre-eclampsia, placental abruption, and uterine rupture were independently associated only with severe early PPH, while non-progressive second stage of labor, induction of labor, and large for gestational age were independently associated with both severe and mild early PPH. When applying an additional logistic regression model, whereas IVF pregnancy, pre-eclampsia, and large for gestational age were independently associated with early PPH among vaginal deliveries only, placenta previa was independently associated with early PPH among CD only.

CONCLUSIONS

Independent risk factors for developing severe PPH solely include IVF pregnancy, previous CD, pre-eclampsia, placental abruption, and uterine rupture. IVF pregnancy, pre-eclampsia, and large for gestational age are independent risk factors for early PPH following vaginal delivery, while placenta previa is independently associated with early PPH after CD only. Due to the recognition of the importance of both the provider and institutional planning and preparation for PPH, the study's results should be viewed within the scope of its retrospective cohort design.

Postpartum acute myometritis suppresses expression of contraction-associated proteins in the gravid uterus

Uterine atony is a major contributor to postpartum hemorrhage. We previously proposed the novel histological concept of postpartum acute myometritis (PAM) to elucidate the pathophysiology of uterine atony. This concept involves the infiltration of macrophages and neutrophils, as well as mast cell and complement activation in the myometrium. However, the pathological mechanism underlying uterine atony in the context of PAM remains unclear. Herein, we focused on uterine contraction-associated proteins (CAPs) including connexin 43 (Cx43), oxytocin receptors (OXR), prostaglandin receptors EP1, EP3, FP, and protease-activated receptor (PAR)-1. This follow-up study aimed to compare CAP expression between PAM and control groups. We selected 38 PAM subjects from the cases enrolled in our amniotic fluid embolism registry between 2011 and 2018. Control tissues from 10 parturients were collected during cesarean section. We stained the myometrial tissues with the following CAP markers, inflammatory cell markers, and other markers: Cx43, OXR, EP1, EP3, FP, PAR-1, C5a receptor, tryptase, neutrophil elastase, CD68, β-actin, and Na+/K+-ATPase. The immunostaining-positive areas of Cx43, OXR, EP1, EP3, and FP standardized by β-actin in the PAM tissue were significantly smaller than in the control group, whereas those of PAR-1 and Na+/K+-ATPase increased significantly in the PAM group. The Cx43- and OXR-positive areas correlated negatively with the immunostaining-positive cell numbers of CD68 and tryptase with halo, respectively. PAM may impair individual and synchronized myocyte contraction, leading to uterine atony refractory to uterotonics. Further cell-based studies are needed to elucidate the molecular mechanism by which inflammatory cells suppress CAP expression.

Quantitative and calculated estimated blood loss in cesarean deliveries for twin and singleton pregnancies: a retrospective analysis

PURPOSE

This study retrospectively assessed blood loss during cesarean deliveries for twin and singleton pregnancies using two distinct methods, quantitative estimation measured during cesarean sections and hematocrit-based calculated estimation.

METHODS

We included scheduled cesarean deliveries for twin or singleton pregnancies at ≥ 34 weeks of gestation. Quantitative blood loss was recorded based on the blood volume in the graduated collector bottle and by weighing the blood-soaked textiles during cesarean sections. The blood loss was calculated using the change in hematocrit levels before and after the cesarean delivery.

RESULTS

We evaluated 403 cases including 44 twins and 359 singletons. Quantitative blood loss during cesarean section was significantly higher in twin pregnancies than that in singleton pregnancies (1117 [440] vs 698 [378] mL; p < 0.001). However, no significant differences were observed in the calculated blood loss between the two groups on the day after delivery (487 mL [692 mL] vs 507 mL [522 mL]; p = 0.861). On post-delivery days 4-5, twin pregnancies were associated with a significantly higher calculated blood loss than singleton pregnancies (725 [868] mL vs 444 [565] mL, p = 0.041). Although a significant moderate correlation between quantitative and calculated blood loss was observed in singleton pregnancies (r = 0.473, p < 0.001), no significant correlation was observed between twin pregnancies (r = 0.053, p = 0.735).

CONCLUSION

Quantitative blood loss measurements during cesarean section may be clinically insufficient in twin pregnancies. Incorporating blood tests and continuous assessments are warranted for enhanced blood loss evaluation, especially in twin pregnancies, owing to the risk of persistent bleeding.

Postpartum haemorrhage and risk of cardiovascular disease in later life: A population-based record linkage cohort study

OBJECTIVE

To investigate the association between postpartum haemorrhage (PPH) and subsequent cardiovascular disease.

DESIGN

Population-based retrospective cohort study, using record linkage between Aberdeen Maternity and Neonatal Databank (AMND) and Scottish healthcare data sets.

SETTING

Grampian region, Scotland.

POPULATION

A cohort of 70 904 women who gave birth after 24 weeks of gestation in the period 1986-2016.

METHODS

We used extended Cox regression models to investigate the association between having had one or more occurrences of PPH in any (first or subsequent) births (exposure) and subsequent cardiovascular disease, adjusted for sociodemographic, medical, and pregnancy and birth-related factors.

MAIN OUTCOME MEASURES

Cardiovascular disease identified from the prescription of selected cardiovascular medications, hospital discharge records or death from cardiovascular disease.

RESULTS

In our cohort of 70 904 women (with 124 795 birth records), 25 177 women (36%) had at least one PPH. Compared with not having a PPH, having at least one PPH was associated with an increased risk of developing cardiovascular disease, as defined above, in the first year after birth (adjusted hazard ratio, aHR 1.96; 95% confidence interval, 95% CI 1.51-2.53; p < 0.001). The association was attenuated over time, but strong evidence of increased risk remained at 2-5 years (aHR 1.19, 95% CI 1.11-1.30, P < 0.001) and at 6-15 years after giving birth (aHR 1.17, 95% CI 1.05-1.30, p = 0.005).

CONCLUSIONS

Compared with women who have never had a PPH, women who have had at least one episode of PPH are twice as likely to develop cardiovascular disease in the first year after birth, and some increased risk persists for up to 15 years.

Association between uterine artery embolization for postpartum hemorrhage and second delivery on maternal and offspring outcomes: a nationwide cohort study

STUDY QUESTION

What are the maternal and neonatal outcomes of second delivery in women who underwent uterine artery embolization (UAE) during their first delivery?

SUMMARY ANSWER

Women who underwent UAE during their first delivery exhibited higher risks of placental problems, preterm births, and postpartum hemorrhage (PPH) in second delivery and the second offspring also showed increased risk of major congenital malformations, admission to the neonatal intensive care units (NICU), necrotizing enterocolitis, intraventricular hemorrhage, and bronchopulmonary dysplasia.

WHAT IS KNOWN ALREADY

UAE is a minimally invasive procedure used as an alternative to hysterectomy for managing severe PPH. However, recent studies have raised concerns about potential obstetric complications, including recurrent PPH, placenta accreta spectrum (PAS), and fetal growth restriction in subsequent delivery following UAE.

STUDY DESIGN SIZE DURATION

This was a nationwide retrospective cohort study using the Korean National Health Insurance Service (K-NHIS) database, covering 50 million individuals from 2004 to 2020. The cohort included 3 616 923 women with live births between 1 January 2005 and 31 December 2019 with follow-up data extending to 31 December 2020.

PARTICIPANTS/MATERIALS SETTING METHODS

The study included women who had their first live birth between 2005 and 2019, excluding those who underwent hysterectomy (without UAE = 3 612 389, UAE = 4534). Among them, we selected women who had single gestation secondary delivery (without UAE = 1 694 600, UAE = 1146). Propensity score matching was used to control for confounding factors, resulting in 11 184 women without UAE and 1119 women with UAE for subsequent analysis.

MAIN RESULTS AND THE ROLE OF CHANCE

Women in the UAE group had significantly higher risks of PAS (odds ratio (OR) = 38.91, 95% CI = 18.61-81.34), placenta previa (OR = 6.98, 95% CI = 5.57-8.75), and preterm birth (OR = 2.23, 95% CI = 1.71-2.90) during their second delivery. The risk of recurrent PPH was also significantly higher (OR = 8.94, 95% CI = 7.19-11.12). Their second offspring were more likely to have major congenital malformations (OR = 1.62, 95% CI = 1.25-2.11) and adverse neonatal outcomes, including NICU admissions (OR = 1.83, 95% CI = 1.48-2.25). Long-term outcomes showed a higher risk of attention-deficit/hyperactivity disorder (hazard ratio = 1.64, 95% CI = 1.03-2.63) but were otherwise comparable to those in the without UAE group.

LIMITATIONS REASONS FOR CAUTION

Retrospective nature of the study may have introduced exposure and outcome misclassifications, despite the reliability of the K-NHIS database. Unmeasured confounders and selection bias due to only including live births could also have influenced the results.

WIDER IMPLICATIONS OF THE FINDINGS

Women with a history of UAE require meticulous prenatal care and close monitoring during subsequent deliveries due to increased risks of complications. Counseling and referral to high-risk medical centers may improve outcomes. Further research is needed to understand the mechanisms of complications in both mothers and offspring at sequential delivery, as well as to refine UAE procedures.

STUDY FUNDING/COMPETING INTERESTS

This study supported by Patient-Centered Clinical Research Coordinating Center (PACEN) funded by the Ministry of Health & Welfare, Republic of Korea (HC21C0123). This study was funded by S.-Y.O. The authors of this manuscript declare no relationships with any companies whose products or services may be related to the subject matter of the article.

TRIAL REGISTRATION NUMBER

N/A.

Discontinuation of Oxytocin in the Second Stage of Labor and its Association with Postpartum Hemorrhage

OBJECTIVE

 The objective of the study was to evaluate whether patients with oxytocin discontinued during the second stage of labor (≥30 minutes prior to delivery) had a lower rate of postpartum hemorrhage (PPH) compared with those with oxytocin continued until delivery or discontinued <30 minutes prior to delivery.

STUDY DESIGN

 Retrospective cohort study was performed from August 1, 2014 to July 31, 2019. Singleton pregnancies of 24 to 42 weeks gestation were included if they reached the second stage of labor and received oxytocin during labor. Patients on anticoagulants were excluded. Patients with oxytocin discontinued ≥30 minutes prior to delivery represented STOPPED and those with oxytocin continued until delivery or discontinued <30 minutes prior to delivery represented CONTINUED. Patient data were abstracted from the electronic medical record. The primary outcome was PPH (≥1,000 mL blood loss). Univariable analyses were performed to compare groups. Multi-variable logistic regression was performed to adjust for prespecified confounders. Planned sub-group analyses by the route of delivery were performed.

RESULTS

 Of 10,421 total patients, 1,288 had oxytocin STOPPED and 9,133 had oxytocin CONTINUED. There were no significant differences in age, race, or ethnicity, body mass index, public insurance, gestational diabetes, or pregnancy-induced hypertension between STOPPED and CONTINUED. The PPH rate was 15.2 and 5.7% in STOPPED and CONTINUED, respectively (p < 0.001). After adjusting for confounders, STOPPED remained at higher odds for PPH (adjusted odds ratio 2.859, 95% confidence interval 2.394, 3.414, p < 0.001). Among cesarean deliveries only, there was no significant difference in the rate of PPH between STOPPED and CONTINUED (38.0 vs. 36.4%, respectively, p = 0.730). However, among vaginal deliveries, the rate of PPH was actually lower in STOPPED than CONTINUED (3.4 vs. 5.2%, respectively, p = 0.024).

CONCLUSION

 The rate of PPH was higher in patients with oxytocin STOPPED compared with CONTINUED. However, among vaginal deliveries, there was a significantly lower rate of PPH in STOPPED. These disparate findings may be explained by the variable impact of second-stage oxytocin on PPH as a function of delivery type.

KEY POINTS

· It is unclear if oxytocin use in the second stage of labor may independently increase the risk of hemorrhage.. · Patients with oxytocin discontinued during the second stage of labor had a higher rate of PPH.. · PPH was significantly lower among vaginal deliveries in patients with oxytocin discontinued..

Impact of cell salvage on hematocrit and post-partum anemia in low hemorrhage risk elective cesarean delivery

BACKGROUND

Postpartum anemia is a significant contributor to peripartum morbidity. The utilization of cell salvage in low risk cases and its impact on postpartum anemia has not been investigated. We therefore aimed to examine the impact of autologous blood transfusion/cell salvage in routine cesarean delivery on postoperative hematocrit and anemia.

STUDY DESIGN AND METHODS

Retrospective cohort study from a perfusion database from a large academic center where cell salvage is performed at the discretion of the obstetrical team. Data from 99 patients was obtained. All patients were scheduled elective cesarean deliveries that took place on the labor and delivery floor. Thirty patients in the cohort had access to cell salvage where autologous blood was transfused after surgery. Pre-procedural hemoglobin/hematocrit measurements were obtained along will postpartum samples that were collected on post-partum day one.

RESULTS

The median amount of blood returned to cell salvage patients was 250 mL [206-250]. Hematocrit changes in cell salvage patients was significantly smaller than controls (-1.85 [-3.87, -0.925] vs -6.4 [-8.3, -4.75]; p < 0.001). The odds of developing new anemia following surgery were cut by 74% for the cell salvage treatment group, compared to the odds for the control group (OR = 0.26 (0.07-0.78); p = 0.028) DISCUSSION: Despite losing more blood on average, patients with access to cell salvage had higher postoperative HCT, less postpartum anemia, and no difference in complications related to transfusion. The utilization of cell salvage for routine cesarean delivery warrants further research.

Rationale for the Potential Use of Recombinant Activated Factor VII in Severe Post-Partum Hemorrhage

Severe post-partum hemorrhage (PPH) is a major cause of maternal mortality worldwide. Recombinant activated factor VII (rFVIIa) has recently been approved by the European Medicines Agency for the treatment of severe PPH if uterotonics fail to achieve hemostasis. Although large randomized controlled trials are lacking, accumulated evidence from smaller studies and international registries supports the efficacy of rFVIIa alongside extended standard treatment to control severe PPH. Because rFVIIa neither substitutes the activity of a missing coagulation factor nor bypasses a coagulation defect in this population, it is not immediately evident how it exerts its beneficial effect. Here, we discuss possible mechanistic explanations for the efficacy of rFVIIa and the published evidence in patients with severe PPH. Recombinant FVIIa may not primarily increase systemic thrombin generation, but may promote local thrombin generation through binding to activated platelets at the site of vascular wall injury. This explanation may also address safety concerns that have been raised over the administration of a procoagulant molecule in a background of increased thromboembolic risk due to both pregnancy-related hemostatic changes and the hemorrhagic state. However, the available safety data for this and other indications are reassuring and the rates of thromboembolic events do not appear to be increased in women with severe PPH treated with rFVIIa. We recommend that the administration of rFVIIa be considered before dilutional coagulopathy develops and used to support the current standard treatment in certain patients with severe PPH.

Predictive performance of Shock Index for postpartum hemorrhage during cesarean delivery

BACKGROUND

The Shock Index (SI), defined as heart rate divided by systolic blood pressure, is reportedly an early surrogate indicator for postpartum hemorrhage (PPH). However, most previous studies have used clinical data of women who delivered vaginally. Therefore, we aimed to evaluate the SI pattern during cesarean delivery and determine its usefulness in detecting PPH.

METHODS

This was a single-center retrospective study using the clinical data of women (n = 331) who underwent cesarean delivery under spinal anesthesia at term between 2018 and 2021. We assessed the SI pattern stratified by total blood loss and evaluated the predictive performance of each vital sign in detecting PPH (total blood loss ≥1000 mL) based on the area under the receiver operating characteristic curve (AUROC).

RESULTS

At 10-15 min after delivery, the mean SI peaked between 0.84 and 0.90 and then decreased to a level between 0.72 and 0.77, which was similar to that upon entering the operating room. Among 331 women, 91 (27.5%) were diagnosed with PPH. There was no correlation between SI and total blood loss (rs = 0.02). The SI had low ability to detect PPH (AUROC 0.54, 95% confidence interval 0.47 to 0.61), which was similar to other vital signs (AUROCs 0.53-0.56).

CONCLUSION

We determined the pattern of SI during cesarean delivery. We found no correlation between SI and total blood loss. Unlike in vaginal delivery, the prognostic accuracy of SI for PPH detection in cesarean delivery was low.

Perioperative outcomes and causes of postpartum hemorrhage in patients undergoing cesarean delivery in Thailand: A comprehensive retrospective study

BACKGROUND

This study aimed to identify the characteristics, causes, perioperative anesthetic, and obstetric outcomes of patients experiencing postpartum hemorrhage (PPH) after cesarean delivery.

METHODS

We retrospectively analyzed patients who underwent cesarean delivery at the largest university hospital in Bangkok, Thailand, during a 5-year period (January 1, 2016-December 31, 2020). PPH was defined as an estimated blood loss (EBL) of ≥ 1000 ml within 24 hours postpartum.

RESULTS

Of 17 187 cesarean deliveries during the study period, 649 patients were included for analysis. The mean EBL was 1774.3 ± 1564.4 ml (range: 1000-26 000 ml). Among the patients, 166 (25.6%) experienced massive PPH (blood loss > 2000 ml). Intraoperative blood transfusions were necessary for 264 patients (40.7%), while 504 individuals (77.7%) needed intraoperative vasopressors. The analysis revealed uterine atony as the leading cause of PPH in 62.7% (n = 407) of the patients, with abnormal placentation following at 29.3% (n = 190). Abnormal placentation was associated with a significantly higher mean EBL of 2345.0 ± 2303.9 ml compared to uterine atony, which had a mean EBL of 1504.0 ± 820.7 ml (P < 0.001). Abnormal placentation also significantly increased the likelihood of blood transfusions and hysterectomies (P < 0.001 for both) and led to more intensive care unit admissions (P = 0.032). The risk of EBL exceeding 2000 ml was markedly higher in patients with abnormal placentation (odds ratio [OR] 5.12, 95% confidence interval [CI] 3.45-7.57, P < 0.001) and in cases involving trauma to the internal organs (OR 2.33, 95% CI 1.16-4.71, P = 0.018) than in patients with uterine atony. The study documented three instances of perioperative cardiac arrest, one of which was fatal.

CONCLUSIONS

These findings highlight the importance of comprehensive perioperative management strategies, including the ready availability of adequate blood and blood products, particularly in scenarios predisposed to significant hemorrhage.

TRIAL REGISTRATION

Clinical trial registration: Clinicaltrial.gov registration number NCT04833556 (April 6, 2021).

External Validation of Postpartum Hemorrhage Prediction Models Using Electronic Health Record Data

OBJECTIVE

 A recent study leveraging machine learning methods found that postpartum hemorrhage (PPH) can be predicted accurately at the time of labor admission in the U.S. Consortium for Safe Labor (CSL) dataset, with a C-statistic as high as 0.93. These CSL models were developed in older data (2002-2008) and used an estimated blood loss (EBL) of ≥1,000 mL to define PPH. We sought to externally validate these models using a more recent cohort of births where blood loss was measured using quantitative blood loss (QBL) methods.

STUDY DESIGN

 Using data from 5,261 deliveries between February 1, 2019 and May 11, 2020 at a single tertiary hospital, we mapped our electronic health record (EHR) data to the 55 predictors described in previously published CSL models. PPH was defined as QBL ≥1,000 mL within 24 hours after delivery. Model discrimination and calibration of the four CSL models were measured using our cohort. In a secondary analysis, we fit new models in our study cohort using the same predictors and algorithms as the original CSL models.

RESULTS

 The original study cohort had a substantially lower rate of PPH, 4.8% (7,279/228,438) versus 25% (1,321/5,261), possibly due to differences in measurement. The CSL models had lower discrimination in our study cohort, with a C-statistic as high as 0.57 (logistic regression). Models refit in our study cohort achieved better discrimination, with a C-statistic as high as 0.64 (random forest). Calibration improved in the refit models as compared with the original models.

CONCLUSION

 The CSL models' accuracy was lower in a contemporary EHR where PPH is assessed using QBL. As institutions continue to adopt QBL methods, further data are needed to understand the differences between EBL and QBL to enable accurate prediction of PPH.

KEY POINTS

· Machine learning methods may help predict PPH.. · EBL models do not generalize when QBL is used.. · Blood loss estimation alters model accuracy..

Protocolized oxytocin infusion for elective cesarean delivery: a retrospective before-and-after study

PURPOSE

To elucidate the clinical impact of the novel oxytocin protocol using a syringe pump with a stratified dose compared with the conventional practice of putting oxytocin into the bag.

METHODS

This is a retrospective cohort study. We collected the data of the patients who underwent elective cesarean delivery under neuraxial anesthesia between June 2019 and May 2020. The patients were allocated to two groups according to oxytocin administration methods; the control group (the attending anesthesiologist put oxytocin 5-10 units in the infusion bag and adjusted manually after childbirth) and the protocol group (the oxytocin protocol gave oxytocin bolus 1 or 3 units depending on the PPH risk, followed by 5 or 10 unit h-1 via a syringe pump). We compared the total amount of oxytocin within 24 h postpartum, estimated blood loss, and adverse clinical events within 24 h postpartum between the two groups.

RESULTS

During the study period, 262 parturients were included. Oxytocin doses of intraoperative and postoperative were significantly lower in the protocol group (9.7 vs. 11.7 units, intraoperative, 15.9 vs. 18 units, postoperative). The subgroup analyses showed that the impact was more remarkable in the low PPH risk than in the high PPH risk. The multivariate linear regression analyses also confirmed the difference. The groups had no significant difference in blood loss, requirement of additional uterotonics, and other adverse events.

CONCLUSIONS

Our oxytocin infusion protocol significantly reduced oxytocin requirements in elective cesarean delivery under neuraxial anesthesia without increasing blood loss. However, we could not find other clinical benefits of the novel protocol.

Postpartum hemorrhage in electronic health records: risk factors at admission and in-hospital occurrence

Objective

Postpartum hemorrhage (PPH) is the leading cause of maternal death globally. Therefore, prevention strategies have been created. The study aimed to evaluate the occurrence of PPH and its risk factors after implementing a risk stratification at admission in a teaching hospital.

Methods

A retrospective cohort involving a database of SISMATER® electronic medical record. Classification in low, medium, or high risk for PPH was performed through data filled out by the obstetrician-assistant. PPH frequency was calculated, compared among these groups and associated with the risk factors.

Results

The prevalence of PPH was 6.8%, 131 among 1,936 women. Sixty-eight (51.9%) of them occurred in the high-risk group, 30 (22.9%) in the medium-risk and 33 (25.2%) in the low-risk group. The adjusted-odds ratio (OR) for PPH were analyzed using a confidence interval (95% CI) and was significantly higher in who presented multiple pregnancy (OR 2.88, 95% CI 1.28 to 6.49), active bleeding on admission (OR 6.12, 95% CI 1.20 to 4.65), non-cephalic presentation (OR 2.36, 95% CI 1.20 to 4.65), retained placenta (OR 9.39, 95% CI 2.90 to 30.46) and placental abruption (OR 6.95, 95% CI 2.06 to 23.48). Vaginal delivery figured out as a protective factor (OR 0.58, 95% CI 0.34 to 0.98).

Conclusion

Prediction of PPH is still a challenge since its unpredictable factor arrangements. The fact that the analysis did not demonstrate a relationship between risk category and frequency of PPH could be attributable to the efficacy of the strategy: Women classified as "high-risk" received adequate medical care, consequently.

Machine Learning Models for Prediction of Maternal Hemorrhage and Transfusion: Model Development Study

BACKGROUND

Current postpartum hemorrhage (PPH) risk stratification is based on traditional statistical models or expert opinion. Machine learning could optimize PPH prediction by allowing for more complex modeling.

OBJECTIVE

We sought to improve PPH prediction and compare machine learning and traditional statistical methods.

METHODS

We developed models using the Consortium for Safe Labor data set (2002-2008) from 12 US hospitals. The primary outcome was a transfusion of blood products or PPH (estimated blood loss of ≥1000 mL). The secondary outcome was a transfusion of any blood product. Fifty antepartum and intrapartum characteristics and hospital characteristics were included. Logistic regression, support vector machines, multilayer perceptron, random forest, and gradient boosting (GB) were used to generate prediction models. The area under the receiver operating characteristic curve (ROC-AUC) and area under the precision/recall curve (PR-AUC) were used to compare performance.

RESULTS

Among 228,438 births, 5760 (3.1%) women had a postpartum hemorrhage, 5170 (2.8%) had a transfusion, and 10,344 (5.6%) met the criteria for the transfusion-PPH composite. Models predicting the transfusion-PPH composite using antepartum and intrapartum features had the best positive predictive values, with the GB machine learning model performing best overall (ROC-AUC=0.833, 95% CI 0.828-0.838; PR-AUC=0.210, 95% CI 0.201-0.220). The most predictive features in the GB model predicting the transfusion-PPH composite were the mode of delivery, oxytocin incremental dose for labor (mU/minute), intrapartum tocolytic use, presence of anesthesia nurse, and hospital type.

CONCLUSIONS

Machine learning offers higher discriminability than logistic regression in predicting PPH. The Consortium for Safe Labor data set may not be optimal for analyzing risk due to strong subgroup effects, which decreases accuracy and limits generalizability.

Association between duration of intrapartum oxytocin exposure and obstetric hemorrhage

PURPOSE

Prolonged duration of intrapartum oxytocin exposure is included as a risk factor within widely adopted obstetric hemorrhage risk stratification tools. However, the duration of exposure that confers increased risk is poorly understood. This study aimed to assess the association between duration of intrapartum oxytocin exposure and obstetric blood loss, as measured by quantitative blood loss, and hemorrhage-related maternal morbidity.

METHODS

This was a retrospective cohort study of all deliveries from 2018 to 2019 at a single medical center. We included patients who had received any intrapartum oxytocin, and we categorized them into 1 of 5 groups: > 0-2, ≥ 2-4, ≥ 4-6, ≥ 6-12, and ≥ 12 h of intrapartum oxytocin exposure. The primary outcomes were mean quantitative blood loss, proportion with obstetric hemorrhage (defined as quantitative blood loss ≥ 1000 mL), and proportion with obstetric hemorrhage-related morbidity, a composite of hemorrhage-related morbidity outcomes. Secondary outcomes were hemorrhage-related pharmacologic and procedural interventions. A stratified analysis was also conducted to examine primary and secondary outcomes by delivery mode.

RESULTS

Of 5332 deliveries between January 1, 2018 and December 31, 2019 at our institution, 2232 (41.9%) utilized oxytocin for induction or augmentation. 326 (14.6%) had exposure of > 0-2 h, 295 (13.2%) ≥ 2-4 h, 298 (13.4%) ≥ 4-6 h, 562 (25.2%) ≥ 6-12 h, and 751 (33.6%) ≥ 12 h. Across all deliveries, there was higher mean quantitative blood loss (p < 0.01) as well as increased odds of obstetric hemorrhage (adjusted odds ratio [aOR] 1.52, 95% confidence interval [CI] 1.21-1.91) for those with ≥ 12 h of oxytocin compared to all groups between > 0-12 h of exposure. In our stratified analysis, ≥ 12 h of oxytocin exposure was associated with higher mean quantitative blood loss (p = 0.04) and odds of obstetric hemorrhage in vaginal deliveries (aOR 1.47, 95% CI: 1.03-2.11), though not in cesarean deliveries (aOR 1.16, 95% CI 0.82-1.62). There were no differences in proportion with obstetric hemorrhage-related morbidity across all deliveries (p = 0.40) or in the stratified analysis.

CONCLUSION

Intrapartum oxytocin exposure of ≥ 12 h was associated with increased quantitative blood loss and odds of obstetric hemorrhage in vaginal, but not cesarean, deliveries.

Oxytocin is not associated with postpartum hemorrhage in labor augmentation in a retrospective cohort study in the United States

BACKGROUND

Previous studies reported conflicting results on the relationship between oxytocin use for labor augmentation and the risk of postpartum hemorrhage, probably because it is rather challenging to disentangle oxytocin use from labor dystocia.

OBJECTIVE

This study aimed to investigate the independent association between oxytocin use for augmentation and the risk of postpartum hemorrhage by using advanced statistical modeling to control for labor patterns and other covariates.

STUDY DESIGN

We used data from 20,899 term, cephalic, singleton pregnancies of patients with spontaneous onset of labor and no previous cesarean delivery from Intermountain Healthcare in Utah in the Consortium on Safe Labor. Presence of postpartum hemorrhage was identified on the basis of a clinical diagnosis. Propensity scores were calculated using a generalized linear mixed model for oxytocin use for augmentation, and covariate balancing generalized propensity score was applied to obtain propensity scores for the duration and total dosage of oxytocin augmentation. A weighted generalized additive mixed model was used to depict dose-response curves between the duration and total dosage of oxytocin augmentation and the outcomes. The average treatment effects of oxytocin use for augmentation on postpartum hemorrhage and estimated blood loss (mL) were assessed by inverse probability weighting of propensity scores.

RESULTS

The odds of both postpartum hemorrhage and estimated blood loss increased modestly when the duration and/or total dosage of oxytocin used for augmentation increased. However, in comparison with women for whom oxytocin was not used, oxytocin augmentation was not clinically or statistically significantly associated with estimated blood loss (6.5 mL; 95% confidence interval, 2.5-10.3) or postpartum hemorrhage (adjusted odds ratio, 1.02; 95% confidence interval, 0.82-1.24) when rigorously controlling for labor pattern and potential confounders. The results remained consistent regardless of inclusion of women with an intrapartum cesarean delivery.

CONCLUSION

The odds of postpartum hemorrhage and estimated blood loss increased modestly with increasing duration and total dosage of oxytocin augmentation. However, in comparison with women for whom oxytocin was not used and after controlling for potential confounders, there was no clinically significant association between oxytocin use for augmentation and estimated blood loss or the risk of postpartum hemorrhage.

What do we know about why women bleed and what do we not know?

Women or people with a uterus are vulnerable to both normal and abnormal bleeding. During the reproductive years, the uterus is prepared physiologically to accept an embryo and support its growth and development during pregnancy, or in the absence of implantation of an embryo, recycle through the process of menstruation and accept an embryo a month or so later. If fertilization takes place and an embryo or embryos implant in the uterus, the fetal trophoblast, or outer cell layer of the embryo, invades and dilates the maternal spiral arteries and forms the placenta. No matter when in gestation a pregnancy ends, at the conclusion of pregnancy, the placenta should separate from the wall of the uterus and be expelled. Abnormal bleeding occurs during pregnancy or after delivery when the normal uteroplacental interface has not been established or is interrupted; during miscarriage; during ectopic pregnancy; during premature separation of the placenta; or during postpartum hemorrhage. Heavy menstrual bleeding, a subset of abnormal menstrual bleeding, can be quantitatively defined as >80 mL of blood loss per cycle. Unlike postpartum hemorrhage, heavy menstrual bleeding is significantly associated with an underlying bleeding disorder. While there is other reproductive tract bleeding in women, notably bleeding at the time of ovulation or with a life-threatening ruptured ectopic pregnancy, the unique bleeding that women experience is predominantly uterine in origin. Many of the unique aspects of uterine hemostasis, however, remain unknown.

CT-001, a novel fast-clearing factor VIIa, enhanced the hemostatic activity in postpartum samples

ABSTRACT

The hemostatic system is upregulated to protect pregnant mothers from hemorrhage during childbirth. Studies of the details just before and after delivery, however, are lacking. Recombinant factor VIIa (rFVIIa) has recently been granted approval by the European Medicines Agency for the treatment of postpartum hemorrhage (PPH). A next-generation molecule, CT-001, is being developed as a potentially safer and more efficacious rFVIIa-based therapy. We sought to evaluate the peripartum hemostatic status of pregnant women and assess the ex vivo hemostatic activity of rFVIIa and CT-001 in peripartum blood samples. Pregnant women from 2 study sites were enrolled in this prospective observational study. Baseline blood samples were collected up to 3 days before delivery. Postdelivery samples were collected 45 (±15) minutes after delivery. Between the 2 time points, soluble fibrin monomer and D-dimer increased whereas tissue factor, FVIII, FV, and fibrinogen decreased. Interestingly, the postdelivery lag time and time to peak in the thrombin generation assay were shortened, and the peak thrombin generation capacity was maintained despite the reduced levels of coagulation proteins after delivery. Furthermore, both rFVIIa and CT-001 were effective in enhancing clotting activity of postdelivery samples in activated partial thromboplastin time, prothrombin time, thrombin generation, and viscoelastic hemostatic assays, with CT-001 demonstrating greater activity. In conclusion, despite apparent ongoing consumption of coagulation factors at the time of delivery, thrombin output was maintained. Both rFVIIa and CT-001 enhanced the upregulated hemostatic activity in postdelivery samples, and consistent with previous studies comparing CT-001 and rFVIIa in vitro and in in vivo, CT-001 demonstrated greater activity than rFVIIa.

Intravenous Calcium to Decrease Blood Loss During Intrapartum Cesarean Delivery: A Randomized Controlled Trial

OBJECTIVE

To evaluate whether prophylactic administration of 1 g of intravenous calcium chloride after cord clamping reduces blood loss from uterine atony during intrapartum cesarean delivery.

METHODS

This single-center, block-randomized, placebo-controlled, double-blind superiority trial compared the effects of 1 g intravenous calcium chloride with those of saline placebo control on blood loss at cesarean delivery. Parturients at 34 or more weeks of gestation requiring intrapartum cesarean delivery after oxytocin exposure in labor were enrolled. Calcium or saline placebo was infused over 10 minutes beginning 1 minute after umbilical cord clamping in addition to standard care with oxytocin. The primary outcome was quantitative blood loss, analyzed by inverse Gaussian regression. Planned subgroup analysis excluded nonatonic bleeding, such as hysterotomy extension, arterial bleeding, and occult placenta accreta. We planned to enroll 120 patients to show a 200-mL reduction in quantitative blood loss in planned subgroup analysis, assuming up to 40% incidence of nonatonic bleeding (80% power, α<0.05).

RESULTS

From April 2022 through March 2023, 828 laboring parturients provided consent and 120 participants were enrolled. Median blood loss was 840 mL in patients allocated to calcium chloride (n=60) and 1,051 mL in patients allocated to placebo (n=60), which was not statistically different (mean reduction 211 mL, 95% CI -33 to 410). In the planned subgroup analysis (n=39 calcium and n=40 placebo), excluding cases of surgeon-documented nonatonic bleeding, calcium reduced quantitative blood loss by 356 mL (95% CI 159-515). Rates of reported side effects were similar between the two groups (38% calcium vs 42% placebo).

CONCLUSION

Prophylactic intravenous calcium chloride administered during intrapartum cesarean delivery after umbilical cord clamping did not significantly reduce blood loss in the primary analysis. However, in the planned subgroup analysis, calcium infusion significantly reduced blood loss by approximately 350 mL. These data suggest that this inexpensive and shelf-stable medication warrants future study as a novel treatment strategy to decrease postpartum hemorrhage, the leading global cause of maternal morbidity and mortality.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov , NCT05027048.

Risk factors for postpartum haemorrhage in women with histologically verified placenta accreta spectrum disorders: a retrospective single-centre cross-sectional study

BACKGROUND

Placenta accreta spectrum (PAS) disorders have been reported with an increasing frequency of up to 3%. The increase in the incidence can be explained by the rising rate of Caesarean section (CS), assisted reproductive technology (ART) and previous uterine surgeries. PAS disorders are usually associated with postpartum haemorrhage (PPH). In our study, we investigated the risk factors for increased blood loss in women with histologically verified PAS disorders independent of delivery mode.

METHODS

In a retrospective single-centre cross-sectional study, 2,223 pregnant women with histologically verified PAS disorders were included. Risk factors for PPH in women with PAS disorders were examined and compared between women with PPH (study group; n = 879) and women with normal blood loss (control group; n = 1150), independent of delivery mode. PAS disorders were diagnosed histologically from the following specimens: placenta, placental-bed specimens, uterine curettage, uterine resection and/or total/partial hysterectomy. Medical data were extracted from clinical records of pregnant women with PAS disorders delivering at the University Hospital Basel between 1986 and 2019. The placenta data of women with PAS disorders were obtained and identified through a search from the database of the Department of Pathology, University Hospital Basel.

RESULTS

Between 1986 and 2019, there were 64,472 deliveries at the University Hospital Basel. PAS disorders were histologically verified in 2,223 women (2,223/64,472), and the prevalence of PAS disorders was 3.45%. A total of 879 women with PAS disorders showed PPH, independent of delivery mode (43.3%). Due to missing data for 194 women, the final analysis was conducted with the remaining 2,029 women. Placenta praevia (O.R. = 6.087; 95% CI, 3.813 to 9.778), previous endometritis (O.R. = 3.011; 95% CI, 1.060 to 9.018), previous manual placenta removal (O.R. = 2.530; 95% CI, 1.700 to 3.796), ART (O.R. = 2.169; 95% CI, 1.593 to 2.960) and vaginal operative birth (O.R. = 1.715; 95% CI, 1.225-2.428) can be considered important risk factors, and previous CS (O.R. = 1.408; 95% CI, 1.016 to 1.950) can be considered a moderate potential risk factor of PPH in women with PAS disorders.

CONCLUSIONS

Placenta praevia, previous endometritis, previous placenta removal, ART and vaginal operative birth can be considered important risk factors of PPH in women with PAS disorders.

STUDY REGISTRATION

The study was registered under http://www.

CLINICALTRIALS

gov (NCT05542043) on 15 September 2022.

Patient blood management to minimize transfusions during the postpartum period

Patient blood management is an evidence-based concept that seeks to minimize blood loss by maintaining adequate hemoglobin levels and optimizing hemostasis during surgery. Since the coronavirus disease 2019 pandemic, patient blood management has gained significance due to fewer blood donations and reduced amounts of blood stored for transfusion. Recently, the prevalence of postpartum hemorrhage (PPH), as well as the frequency of PPH-associated transfusions, has steadily increased. Therefore, proper blood transfusion is required to minimize PPH-associated complications while saving the patient's life. Several guidelines have attempted to apply this concept to minimize anemia during pregnancy and bleeding during delivery, prevent bleeding after delivery, and optimize recovery methods from anemia. This study systematically reviewed various guidelines to determine blood loss management in pregnant women.

Postpartum haemorrhage occurring in UK midwifery units: A national population-based case-control study to investigate incidence, risk factors and outcomes

OBJECTIVES

To estimate the incidence of, and investigate risk factors for, postpartum haemorrhage (PPH) requiring transfer to obstetric care following birth in midwifery units (MU) in the UK; to describe outcomes for women who experience PPH requiring transfer to obstetric care.

METHODS

We conducted a national population-based case-control study in all MUs in the UK using the UK Midwifery Study System (UKMidSS). Between September 2019 and February 2020, 1501 women with PPH requiring transfer to obstetric care following birth in an MU, and 1475 control women were identified. We used multivariable logistic regression, generating adjusted odds ratios (aORs) and 95% confidence intervals (CIs) to investigate risk factors for PPH requiring transfer to obstetric care.

RESULTS

The incidence of PPH requiring transfer to obstetric care following birth in an MU was 3.7% (95% CI 3.6%-3.9%). Factors independently associated with PPH requiring transfer to obstetric care were smoking during pregnancy (aOR = 0.73; 95% CI 0.56-0.94), nulliparity (aOR = 1.96; 95% CI 1.66-2.30), previous PPH (aOR = 2.67; 95% CI 1.67-4.25), complications in a previous pregnancy other than PPH (aOR = 2.40; 95% CI 1.25-4.60), gestational age ≥41 weeks (aOR = 1.36; 95% CI 1.10-1.69), instrumental birth (aOR = 2.69; 95% CI 1.53-4.72), third stage of labour ≥60 minutes (aOR = 5.56; 95% CI 3.93-7.88), perineal trauma (aOR = 4.67; 95% CI 3.16-6.90), and birthweight 3500-3999g (aOR = 1.71; 95% CI 1.42-2.07) or ≥4000g (aOR = 2.31; 95% CI 1.78-3.00). One in ten (10.6%) cases received a blood transfusion and one in five (21.0%) were admitted to higher level care.

CONCLUSIONS

The risk factors identified in this study align with those identified in previous research and with current guidelines for women planning birth in an MU in the UK. Maternal outcomes after PPH were broadly reassuring and indicative of appropriate management. NHS organisations should ensure that robust guidelines are in place to support management of PPH in MUs.

Severe maternal morbidity following stillbirth in Western Australia 2000-2015: a population-based study

PURPOSE

There is scant literature about the management of stillbirth and the subsequent risk of severe maternal morbidity (SMM). We aimed to assess the risk of SMM associated with stillbirths compared with live births and whether this differed by the presence of maternal comorbidities.

METHODS

In this retrospective cohort study, we used a population-based dataset of all stillbirths and live births ≥ 20 weeks' gestation in Western Australia between 2000 and 2015. SMM was identified using a published Australian composite for use with routinely collected hospital morbidity data. Maternal comorbidities were identified in the Hospital Morbidity Data Collection or the Midwives Notification System using a modified Australian chronic disease composite. Multivariable Poisson regression was used to estimate relative risks (RRs) and 95% confidence intervals (CIs) for factors associated with SMM in analyses stratified by the presence of maternal comorbidities. Singleton and multiple pregnancies were examined separately.

RESULTS

This study included 458,639 singleton births (2319 stillbirths and 456,320 live births). The adjusted RRs for SMM among stillbirths were 2.30 (95% CI 1.77, 3.00) for those without comorbidities and 4.80 (95% CI 4.11, 5.59) (Interaction P value < 0.0001) for those with comorbidities compared to live births without and with comorbidities, respectively.

CONCLUSION

In Western Australia between 2000 and 2015, mothers of stillbirths both with and without any maternal comorbidities had an increased risk of SMM compared with live births. Further investigation into why women who have had a stillbirth without any existing conditions or pregnancy complications develop SMM is warranted.

Singleton pregnancy using in vitro fertilization or intracytoplasmic sperm injection does not increase risk of bleeding in cesarean delivery: a retrospective cohort study

PURPOSE

Several studies indicate that assisted reproductive technology (ART) including in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) pregnancies carries increased risk of complications including postpartum hemorrhage (PPH). However, the association between IVF/ICSI and the bleeding risk particularly in cesarean delivery has not been systematically assessed. The aim of this study was to evaluate bleeding risk during and after cesarean delivery in parturients who conceived using IVF or ICSI.

METHODS

This is a retrospective observational study analyzing data from 310 parturients who underwent cesarean delivery: 155 who had conceived using IVF or ICSI (IVF/ICSI group) and 155 age and year of delivery matched controls who had conceived spontaneously (control group). The primary outcome measure was the amount of blood lost during and within 24 h after cesarean delivery. Secondary outcome measure was the incidence of severe PPH. With 132 parturients in each group, we had 90% power to detect a 200 mL difference in the bleeding amount, at a 0.05 two-sided significance level.

RESULTS

The amount of bleeding in the IVF/ICSI group was 1234 ± 669 mL, which was 124 mL (11.2%) greater than that in the control group (95% CI - 34 to 282; p = 0.12). The incidence of severe PPH in the IVF/ICSI group and in the control group was 23.9% and 16.8%, respectively (p = 0.16), and the unadjusted odds ratio was 1.6 (95% CI, 0.9-2.7; p = 0.12). No significant independent effect of IVF/ICSI on the bleeding amount and the incidence of severe PPH was observed in multivariable regression analyses (p = 0.22, p = 0.16).

CONCLUSION

In this study, IVF and ICSI were not associated with increasing risk of bleeding in cesarean delivery.

Analysis of Heat Exposure During Pregnancy and Severe Maternal Morbidity

Importance

The rate of severe maternal morbidity (SMM) is continuously increasing in the US. Evidence regarding the associations of climate-related exposure, such as environmental heat, with SMM is lacking.

Objective

To examine associations between long- and short-term maternal heat exposure and SMM.

Design, Setting, and Participants

This retrospective population-based epidemiological cohort study took place at a large integrated health care organization, Kaiser Permanente Southern California, between January 1, 2008, and December 31, 2018. Data were analyzed from February to April 2023. Singleton pregnancies with data on SMM diagnosis status were included.

Exposures

Moderate, high, and extreme heat days, defined as daily maximum temperatures exceeding the 75th, 90th, and 95th percentiles of the time series data from May through September 2007 to 2018 in Southern California, respectively. Long-term exposures were measured by the proportions of different heat days during pregnancy and by trimester. Short-term exposures were represented by binary variables of heatwaves with 9 different definitions (combining percentile thresholds with 3 durations; ie, ≥2, ≥3, and ≥4 consecutive days) during the last gestational week.

Main Outcomes and Measures

The primary outcome was SMM during delivery hospitalization, measured by 20 subconditions excluding blood transfusion. Discrete-time logistic regression was used to estimate associations with long- and short-term heat exposure. Effect modification by maternal characteristics and green space exposure was examined using interaction terms.

Results

There were 3446 SMM cases (0.9%) among 403 602 pregnancies (mean [SD] age, 30.3 [5.7] years). Significant associations were observed with long-term heat exposure during pregnancy and during the third trimester. High exposure (≥80th percentile of the proportions) to extreme heat days during pregnancy and during the third trimester were associated with a 27% (95% CI, 17%-37%; P < .001) and 28% (95% CI, 17%-41%; P < .001) increase in risk of SMM, respectively. Elevated SMM risks were significantly associated with short-term heatwave exposure under all heatwave definitions. The magnitude of associations generally increased from the least severe (HWD1: daily maximum temperature >75th percentile lasting for ≥2 days; odds ratio [OR], 1.32; 95% CI, 1.17-1.48; P < .001) to the most severe heatwave exposure (HWD9: daily maximum temperature >95th percentile lasting for ≥4 days; OR, 2.39; 95% CI, 1.62-3.54; P < .001). Greater associations were observed among mothers with lower educational attainment (OR for high exposure to extreme heat days during pregnancy, 1.43; 95% CI, 1.26-1.63; P < .001) or whose pregnancies started in the cold season (November through April; OR, 1.37; 95% CI, 1.24-1.53; P < .001).

Conclusions and Relevance

In this retrospective cohort study, long- and short-term heat exposure during pregnancy was associated with higher risk of SMM. These results might have important implications for SMM prevention, particularly in a changing climate.

Effect of an oxytocin protocol on secondary uterotonic use in patients undergoing Cesarean delivery

PURPOSE

Protocol-driven oxytocin regimens can reduce oxytocin administration compared with a nonprotocol free-flow continuous infusion. Our aim was to compare secondary uterotonic use between a modified "rule of threes" oxytocin protocol and a free-flow continuous oxytocin infusion after Cesarean delivery.

METHODS

We conducted a retrospective before-and-after study to compare patients who underwent Cesarean delivery between 1 January 2010 and 31 December 2013 (preprotocol) with patients who underwent Cesarean delivery between 1 January 2015 and 31 August 2017 (postprotocol). The preprotocol group received free-flow oxytocin administration and the postprotocol group received oxytocin according to a modified rule of threes algorithm. The primary outcome was secondary uterotonic use and the secondary outcomes included blood transfusion, hemoglobin value < 8 g·dL-1, and estimated blood loss.

RESULTS

In total, 4,010 Cesarean deliveries were performed in 3,637 patients (2,262 preprotocol and 1,748 postprotocol). The odds of receiving secondary uterotonic drugs were increased in the postprotocol group (odds ratio [OR], 1.33; 95% confidence interval [CI], 1.04 to 1.70; P = 0.02). Patients in the postprotocol group were less likely to receive a blood transfusion. Nevertheless, the two groups were similar for the composite end point of transfusion or hemoglobin < 8 g·dL-1 (OR, 0.86; 95% CI, 0.66 to 1.11; P = 0.25). The odds of an estimated blood loss greater than 1,000 mL were reduced in the postprotocol group (OR, 0.64; 95% CI, 0.50 to 0.84; P = 0.001).

CONCLUSIONS

Patients in the modified rule of threes oxytocin protocol group were more likely to receive a secondary uterotonic than those in the preprotocol group. Estimated blood loss and transfusion outcomes were similar.

Management of postpartum hemorrhage in a patient with bicornuate uterus using the B-Lynch suture. Case report and review of the literature

Objectives

To describe the use of the B-Lynch suture in a case of postpartum hemorrhage of a woman with bicornuate uterus, and to carry out a review of the literature on PPH control strategies in patients with müllerian anomalies, maternal outcomes in terms of hemorrhage control, as well as early and late complications.

Material and methods

Case report of a patient with bicornuate uterus who presented to a regional referral hospital with postpartum hemorrhage following a cesarean section, which was successfully controlled using the B-Lynch suture. A search was conducted in the PubMed, Embase, Medline, Google Scholar and LILACS databases. The MeSh terms used were: “Uterine Atony,” “Postpartum Hemorrhage,” “Immediate Postpartum Hemorrhage,” “Bicornuate Uterus,” “Müllerian Anomalies,” “Müllerian Duct Abnormalities”. Case reports and case series of patients with müllerian malformations and PPH not responding to initial pharmacological management in whom conservative surgical procedures were used to control bleeding were included. A narrative analysis of the findings was carried out based on study characteristics, techniques used and complications.

Results

Five studies were selected, 4 case reports and 1 case series which included 12 women with uterine malformations who developed PPH and in whom surgical management (uterine compression sutures) or devices (intrauterine balloon) were used for hemorrhage control. Bleeding was successfully controlled in 11 cases, with hysterectomy required only in one case (8.3 %). No long-term complications were reported.

Conclusions

The literature on PPH management in women with müllerian uterine malformations is limited to case reports in which either compression sutures or medical devices such as intrauterine balloons were used. The B-Lynch-type compression suture appears to be a good option for controlling PPH in these women in order to preserve fertility, with a low rate of complications. Further documentation of these types of cases is needed in order to build the evidence regarding the usefulness of this technique for controlling postpartum uterine bleeding in this population.

Coagulation management and transfusion in massive postpartum hemorrhage

PURPOSE OF REVIEW

Excessive bleeding during and following childbirth remains one of the leading causes of maternal mortality.

RECENT FINDINGS

Current guidelines differ in definitions and recommendations on managing transfusion and hemostasis in massive postpartum hemorrhage (PPH). Insights gained from trauma-induced coagulopathy are not directly transferable to the obstetric population due to gestational alterations and a differing pathophysiology.

SUMMARY

Factor deficiency is uncommon at the beginning of most etiologies of PPH but will eventually develop from consumption and depletion in the absence of bleeding control. The sensitivity of point-of-care tests for fibrinolysis is too low and may delay treatment, therefore tranexamic acid should be started early at diagnosis even without signs for hyperfibrinolysis. Transfusion management may be initiated empirically, but is best to be guided by laboratory and viscoelastic assay results as soon as possible. Hypofibrinogenemia is well detected by point-of-care tests, thus substitution may be tailored to individual needs, while reliable thresholds for fresh frozen plasma (FFP) and specific components are yet to be defined. In case of factor deficiency, prothrombin complex concentrate or lyophilized plasma allow for a more rapid restoration of coagulation than FFP. If bleeding and hemostasis are under control, a timely anticoagulation may be necessary.

Postpartum Hemorrhage-Epidemiology, Risk Factors, and Causes

The incidence of postpartum hemorrhage (PPH) is increasing worldwide and in the United States. Coinciding, is the increased rate of severe maternal morbidity with blood transfusion in the United States over the past 2 decades. Consequences of PPH can be life-threatening and carry significant cost burden to the health care system. This review will discuss the current trends, distribution, and risk factors for PPH. Causes of PPH will be explored in detail.

Prediction of postpartum hemorrhage using traditional statistical analysis and a machine learning approach

BACKGROUND

Early detection of postpartum hemorrhage risk factors by healthcare providers during pregnancy and the postpartum period may allow healthcare providers to act to prevent it. Developing a prediction model that incorporates several risk factors and accurately calculates the overall risk for postpartum hemorrhage is necessary.

OBJECTIVE

This study used a traditional analytical approach and a machine learning model to predict postpartum hemorrhage.

STUDY DESIGN

Women who gave birth at the Khaleej-e-Fars Hospital in Bandar Abbas, Iran, were evaluated retrospectively between January 1, 2020, and January 1, 2022. These pregnant women were divided into 2 groups, namely those who had postpartum hemorrhage and those who did not. We used 2 approaches for the analysis. At the first level, we used the traditional analysis methods. Demographic factors, maternal comorbidities, and obstetrical factors were compared between the 2 groups. A bivariate logistic regression analysis of the risk factors for postpartum hemorrhage was done to estimate the crude odds ratios and their 95% confidence intervals. In the second level, we used machine learning approaches to predict postpartum hemorrhage.

RESULTS

Of the 8888 deliveries, we identified 163 women with recorded postpartum hemorrhage, giving a frequency of 1.8%. According to a traditional analysis, factors associated with an increased risk for postpartum hemorrhage in a bivariate logistic regression analysis were living in a rural area (odds ratio, 1.41; 95% confidence interval, 1.08-1.98); primiparity (odds ratio, 3.16; 95% confidence interval, 1.90-4.75); mild to moderate anemia (odds ratio, 5.94; 95% confidence interval 2.81-8.34); severe anemia (odds ratio, 6.01; 95% confidence interval 3.89-11.09); abnormal placentation (odds ratio, 7.66; 95% confidence interval, 2.81-17.34); fetal macrosomia (odds ratio, 8.14; 95% confidence interval, 1.02-14.47); shoulder dystocia (odds ratio, 7.88; 95% confidence interval, 1.07-13.99); vacuum delivery (odds ratio, 2.01; 95% confidence interval, 1.15-5.98); cesarean delivery (odds ratio, 1.86; 95% confidence interval, 1.12-3.79); and general anesthesia during cesarean delivery (odds ratio, 7.66; 95 % confidence interval, 3.11-9.36). According to machine learning analysis, the top 5 algorithms were XGBoost regression (area under the receiver operating characteristic curve of 99%), XGBoost classification (area under the receiver operating characteristic curve of 98%), LightGBM (area under the receiver operating characteristic curve of 94%), random forest regression (area under the receiver operating characteristic curve of 86%), and linear regression (area under the receiver operating characteristic curve of 78%). However, after considering all performance parameters, the XGBoost classification was found to be the best model to predict postpartum hemorrhage. The importance of the variables in the linear regression model, similar to traditional analysis methods, revealed that macrosomia, general anesthesia, anemia, shoulder dystocia, and abnormal placentation were considered to be weighted factors, whereas XGBoost classification considered living residency, parity, cesarean delivery, education, and induced labor to be weighted factors.

CONCLUSION

Risk factors for postpartum hemorrhage can be identified using traditional statistical analysis and a machine learning model. Machine learning models were a credible approach for improving postpartum hemorrhage prediction with high accuracy. More research should be conducted to analyze appropriate variables and prepare big data to determine the best model.

Automated Alert System of Second-Line Uterotonic Drug Administration

Multidisciplinary team management of postpartum hemorrhage (PPH) is needed to optimize care and improve outcomes. Lucile Packard Children's Hospital, Stanford, is a tertiary referral center with 4600 deliveries/y (>70% high-risk deliveries), and there have been times when the obstetric anesthesia team was alerted late or not at all for PPHs. Introduction of an automated alert process to the obstetric anesthesia team when a second-line uterotonic drug was administered has ensured prompt evaluation. Utilization of this automated drug alert system has improved communication and reduced failure to inform the obstetric anesthesiology team of PPH after vaginal and cesarean deliveries.

The Effect of 2016 Chinese second-child policy and different maternal age on pregnancy outcomes in Hebei Province, China

OBJECTIVE

To explore the effect of the 2016 Chinese second child policy and different maternal ages on adverse perinatal outcomes.

METHODS

Clinical data were collected from 22 monitoring hospitals in Hebei Province from January 1, 2013, to December 31, 2021. A total of 413,892 parturient were divided into 3 groups based on delivery age: 20-34, 35-39, and 40-55 years old. The clinical data were analyzed to explore the relationship among the 2016 Chinese second-child policy, maternal age, and various pregnancy risks.

RESULTS

Pregnancy complications showed an upward trend from 2013 to 2021.The top 10 incidences of pregnancy complications in Hebei Province were anemia, small for gestational age (SGA), large for gestational age (LGA), macrosomia, gestational diabetes mellitus (GDM), premature delivery, preeclampsia (PE), postpartum hemorrhage (PPH), placenta previa, and placental abruption. The two-child policy was implemented in 2016. The incidence of pregnancy complications, anemia, GDM, PE, placental abruption, cesarean delivery, premature delivery, SGA, LGA, macrosomia in 2016-2021 was significantly higher than that in 2013-2015 (P<0.05), and the proportion of women of advanced maternal age (AMA, ≥ 35 years old) increased from 2013 to 2021. Advanced maternal age was a risk factor for most assessed adverse pregnancy outcomes, including GDM, PE, placenta previa, placenta abruption, cesarean delivery, PPH, premature delivery, SGA, LGA and macrosomia.

CONCLUSION

After the adjustment of the "second-child" policy, the incidence of pregnancy complications increased. Moreover, the risk of adverse pregnancy outcomes in AMA has increased. Early prevention and intervention should be implemented to cope with the occurrence of adverse perinatal outcomes.

Vacuum-induced hemorrhage control versus uterine balloon tamponade for postpartum hemorrhage

OBJECTIVE

To compare maternal outcomes of uterine balloon tamponade (UBT) versus an intrauterine vacuum-induced hemorrhage-control device (VHD) for the management of primary postpartum hemorrhage (PPH).

METHODS

Retrospective cohort of all patients with PPH due to uterine atony treated with an intrauterine device within a university health system from January 2019 to June 2021. The primary outcome of massive transfusion, defined as PPH requiring transfusion of ≥ 4 units of packed red blood cells (PRBC), was compared between 2 groups: UBT (n = 78) versus VHD (n = 36). Statistical analysis included use of Chi-squared and Wilcoxon rank sum tests with statistical significance set at P < 0.05.

RESULTS

Baseline characteristics were similar between the 2 groups. The proportion of patients who received ≥ 4 units of PRBC was significantly lower in the VHD group compared to the UBT group (2.8% vs. 20.5%, P = <0.01). The proportion of patients who were transfused ≥ 2 units of PRBC and median estimated blood loss (EBL) were also both significantly lower in the VHD group compared to the UBT group (36.1% vs. 57.7%, P = <0.01, and 1 500 mL vs. 1 875 mL, P = 0.02, respectively). Rates of other secondary outcomes were similar between the 2 groups.

CONCLUSION

Our data suggest that the use of intrauterine VHD in the management of PPH is associated with a lower number of massive transfusions and EBL compared to UBT. Randomized controlled trials are needed before drawing definitive conclusions on which device is more effective in this setting.

Beyond uterine atony: characterizing postpartum hemorrhage coagulopathy

BACKGROUND

Postpartum hemorrhage is a leading cause of morbidity and mortality worldwide, yet the associated early coagulopathy is not well defined.

OBJECTIVE

We hypothesized that women who develop postpartum hemorrhage have a distinct derangement of thrombin generation and coagulation factors compared with postpartum women without postpartum hemorrhage.

STUDY DESIGN

This prospective study of pregnant patients with postpartum hemorrhage was completed at a single urban hospital. Blood was drawn on postpartum hemorrhage diagnosis and 2 and 4 hours later. Assays of patients with postpartum hemorrhage included thrombelastography, whole blood thrombin generation, coagulation factor activity, tissue factor levels and activity, and tissue factor pathway inhibitor levels, which were compared with that of patients without postpartum hemorrhage.

RESULTS

A total of 81 patients were included in this study. Of those patients, 66 had postpartum hemorrhage, and 15 served as controls. Compared with patients without PPH, patients with postpartum hemorrhage had lower fibrinogen levels (469.0 mg/dL vs 411.0 mg/dL; P=.02), increased tissue plasminogen activator resistance (fibrinolysis 30 minutes after maximal clot strength: 8.7% vs 4.2%; P=.02), decreased peak thrombin concentration (150.2 nM vs 40.7 nM; P=.01), and decreased maximal rate of thrombin generation (60.1 nM/minute vs 2.8 nM/minute; P=.02). Furthermore, compared with patients without postpartum hemorrhage, patients with postpartum hemorrhage had decreased tissue factor levels (444.3 pg/mL vs 267.1 pg/mL; P=.02) and increased tissue factor pathway inhibitor levels (0.6 U/mL vs 0.8 U/mL; P=.04), with decreased tissue factor pathway inhibitor ratios (624 vs 299; P=.01).

CONCLUSION

PPH is not only an issue of uterine tone and mechanical bleeding but also a distinct coagulopathy that is characterized by decreased fibrinogen level, clot breakdown resistance, and markedly low thrombin generation. This pathology seemed to be driven by low tissue factor and high tissue factor pathway inhibitor levels.

Two oxytocin analogs, N-(p-fluorobenzyl) glycine and N-(3-hydroxypropyl) glycine, induce uterine contractions ex vivo in ways that differ from that of oxytocin

Contraction of the uterus is critical for parturient processes. Insufficient uterine tone, resulting in atony, can potentiate postpartum hemorrhage; thus, it is a major risk factor and is the main cause of maternity-related deaths worldwide. Oxytocin (OT) is recommended for use in combination with other uterotonics for cases of refractory uterine atony. However, as the effect of OT dose on uterine contraction and control of blood loss during cesarean delivery for labor arrest are highly associated with side effects, small amounts of uterotonics may be used to elicit rapid and superior uterine contraction. We have previously synthesized OT analogs 2 and 5, prolines at the 7th positions of which were replaced with N-(p-fluorobenzyl) glycine [thus, compound 2 is now called fluorobenzyl (FBOT)] or N-(3-hydroxypropyl) glycine [compound 5 is now called hydroxypropyl (HPOT)], which exhibited highly potent binding affinities for human OT receptors in vitro. In this study, we measured the ex vivo effects of FBOT and HPOT on contractions of uteri isolated from human cesarean delivery samples and virgin female mice. We evaluated the potency and efficacy of the analogs on uterine contraction, additivity with OT, and the ability to overcome the effects of atosiban, an OT antagonist. In human samples, the potency rank judged by the calculated EC50 (pM) was as follows: HPOT (189) > FBOT (556) > OT (5,340) > carbetocin (12,090). The calculated Emax was 86% for FBOT and 75% for HPOT (100%). Recovery from atosiban inhibition after HPOT treatment was as potent as that after OT treatment. HPOT showed additivity with OT. FBOT (56 pM) was found to be the strongest agonist in virgin mouse uterus. HPOT and FBOT demonstrated high potency and partial agonist efficacy in the human uterus. These results suggested that HPOT and FBOT are highly uterotonic for the human uterus and performed better than OT, indicating that they may prevent postpartum hemorrhage.

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.

The impact of assisted reproductive technology on the risk of postpartum hemorrhage: Difference by the mode of delivery and embryo transfer

AIM

The frequency of postpartum hemorrhage (PPH) is increasing in developed countries, and some reports suggest that assisted reproductive technology (ART) increases various perinatal complications, including PPH. We investigated whether the effect of ART pregnancies on the incidence of PPH is modified by the mode of delivery.

METHODS

A retrospective cohort study was performed. We analyzed the medical records of 2914 pregnant women, including 411 pregnancies achieved by ART, which were delivered in our hospital from 2017 to 2020. PPH was defined as hemorrhage exceeding the 90th percentile of blood loss per the mode of delivery and number of fetuses. Multivariable logistic regression analysis was used to assess the association between ART and PPH. Propensity score-matched analyses were used to assess the difference in the incidence of PPH by the mode of delivery.

RESULTS

As previously reported, multivariable logistic regression analysis showed that ART pregnancy is an independent risk factor for PPH. Propensity score-matched analysis for with and without ART showed a 3.39-fold higher incidence of PPH for ART pregnancy in the vaginal delivery group (p < 0.001).

CONCLUSIONS

The effect of ART pregnancies on the incidence of PPH differed depending on the mode of delivery. Only in vaginal delivery, ART pregnancy increased the incidence of PPH.

Traditional uterine tamponade and vacuum-induced uterine tamponade devices in obstetrical hemorrhage management

Obstetrical hemorrhage is the leading cause of maternal morbidity and mortality worldwide, and the rates of severe hemorrhage are increasing. There is a crucial need to expand treatment options for hemorrhage to address this global crisis. Over the last decade, the evolution of hemorrhage control devices has contributed to advancements in obstetrical hemorrhage management. The number of existing hemorrhage control devices and techniques has increased markedly in recent years, and new devices are in development. The current evidence for established and investigational hemorrhage control devices has been summarized in this review. Of note, 2 main categories of devices exist: traditional uterine tamponade and vacuum-induced uterine tamponade. Although traditional intrauterine balloon tamponade devices are currently used widely in postpartum hemorrhage management, novel hemorrhage control devices and techniques have been developed. These include the minisponge tamponade device, the Jada System, a modified Bakri balloon technique, and a suction tube uterine tamponade technique. Reassuring safety data and preliminary efficacy data from pilot studies of these novel techniques support the powerful role intrauterine devices can play in obstetrical hemorrhage management. This review aimed to improve awareness of device options so that continued efforts can be made to integrate new technology into hemorrhage management protocols. Well-designed studies inclusive of new hemorrhage control devices are essential to understanding where new technology fits into preexisting obstetrical hemorrhage algorithms. In addition, access to new tamponade technology remains limited on a global scale. Programs aimed at both increasing access to devices and expanding educational initiatives are essential to make new technology a standard component for hemorrhage management.

Evaluating the Association Between Fibrinogen and Rotational Thromboelastometry and the Progression to Severe Obstetric Hemorrhage

AIM

This study aims to investigate the ability of fibrinogen and rotational thromboelastometry (ROTEM) parameters measured at obstetric hemorrhage protocol initiation to predict severe hemorrhage.

METHODS

In this retrospective study we included patients whose hemorrhage was managed with an obstetric massive transfusion protocol. Fibrinogen and ROTEM parameters EXTEM clotting time (CT), clot formation time (CFT), alpha angle, A10, A20, lysis index 30 min after CT (LI30), FIBTEM A10, A20, were measured at initiation of the protocol with transfusion based on a predefined algorithm. Patients were grouped into either severe or nonsevere hemorrhage based on: peripartum fall in hemoglobin ≥4 g/dL, transfusion of ≥4 units of blood product, invasive procedures for hemorrhage control, intensive care unit admission, or death.

RESULTS

Of the 155 patients included, 108 (70%) progressed to severe hemorrhage. Fibrinogen, EXTEM alpha angle, A10, A20, FIBTEM A10, A20 were significantly lower in the severe hemorrhage group while the CFT was significantly prolonged in the severe hemorrhage group. In univariate analysis, predicted progression to severe hemorrhage yielded areas under the receiver operating characteristic curve (95% confidence interval [CI]) of: fibrinogen: 0.683 (0.591-0.776), CFT: 0.671 (0.553, 0.789), EXTEM alpha angle: 0.690 (0.577-0.803), A10: 0.693 (0.570-0.815), A20: 0.678 (0.563-0.793), FIBTEM A10: 0.726 (0.605-0.847), and A20: 0.709 (0.594-0.824). In a multivariable model, fibrinogen was independently associated with severe hemorrhage (odds ratio [95% CI] = 1.037 [1.009-1.066]) for every 50 mg/dL decrease in fibrinogen drawn at obstetric hemorrhage massive transfusion protocol initiation.

CONCLUSION

Both fibrinogen and ROTEM parameters measured at the initiation of an obstetric hemorrhage protocol are useful parameters for predicting severe hemorrhage.

Predicting risk of peripartum blood transfusion during vaginal and cesarean delivery: A risk prediction model

OBJECTIVE

The objective of this study is to develop a model that will help predict the risk of blood transfusion using information available prior to delivery.

STUDY DESIGN

The study is a secondary analysis of the Consortium on Safe Labor registry. Women who had a delivery from 2002 to 2008 were included. Pre-delivery variables that had significant associations with transfusion were included in a multivariable logistic regression model predicting transfusion. The prediction model was internally validated using randomly selected samples from the same population of women.

RESULTS

Of 156,572 deliveries, 5,463 deliveries (3.5%) required transfusion. Women who had deliveries requiring transfusion were more likely to have a number of comorbidities such as preeclampsia (6.3% versus 4.1%, OR 1.21, 95% CI 1.08-1.36), placenta previa (1.8% versus 0.4%, OR 4.11, 95% CI 3.25-5.21) and anemia (10.6% versus 5.4%, OR 1.30, 95% CI 1.21-1.41). Transfusion was least likely to occur in university teaching hospitals compared to community hospitals. The c statistic was 0.71 (95% CI 0.70-0.72) in the derivation sample. The most salient predictors of transfusion included type of hospital, placenta previa, multiple gestations, diabetes mellitus, anemia, asthma, previous births, preeclampsia, type of insurance, age, gestational age, and vertex presentation. The model was well-calibrated and showed strong internal validation.

CONCLUSION

The model identified independent risk factors that can help predict the risk of transfusion prior to delivery. If externally validated in another dataset, this model can assist health care professionals counsel patients and prepare facilities/resources to reduce maternal morbidity.

Postpartum Hemorrhage Trends and Outcomes in the United States, 2000-2019

OBJECTIVE

To analyze temporal trends in and risk factors for postpartum hemorrhage and to analyze the association of risk factors with postpartum hemorrhage-related interventions such as blood transfusion and peripartum hysterectomy.

METHODS

This repeated cross-sectional study analyzed delivery hospitalizations from 2000 to 2019 in the National (Nationwide) Inpatient Sample. Trends analyses were conducted using joinpoint regression to estimate the average annual percent change (AAPC) with 95% CIs. Unadjusted and adjusted survey-weighted logistic regression models were performed to evaluate the relationship between postpartum hemorrhage risk factors and likelihood of 1) postpartum hemorrhage, 2) postpartum hemorrhage that requires blood transfusion, and 3) peripartum hysterectomy in the setting of postpartum hemorrhage, with unadjusted odds ratios and adjusted odds ratios with 95% CIs as measures of association.

RESULTS

Of an estimated 76.7 million delivery hospitalizations, 2.3 million (3.0%) were complicated by postpartum hemorrhage. From 2000 to 2019, the rate of postpartum hemorrhage increased from 2.7% to 4.3% (AAPC 2.6%, 94% CI 1.7-3.5%). Over the study period, the proportion of deliveries to individuals with at least one postpartum hemorrhage risk factor increased from 18.6% to 26.9% (AAPC 1.9%, 95% CI 1.7-2.0%). Among deliveries complicated by postpartum hemorrhage, blood transfusions increased from 5.4% to 16.7% from 2000 to 2011 and then decreased from 16.7% to 12.6% from 2011 to 2019. Peripartum hysterectomy among hospitalized individuals with postpartum hemorrhage increased from 1.4% to 2.4% from 2000 to 2009, did not change significantly from 2009 to 2016, and then decreased significantly from 2.1% to 0.9% from 2016 to 2019 (AAPC -27.0%, 95% CI -35.2% to -17.6%). Risk factors associated with postpartum hemorrhage and transfusion and hysterectomy in the setting of postpartum hemorrhage included prior cesarean delivery with previa or placenta accreta, placenta previa without prior cesarean delivery, and antepartum hemorrhage or placental abruption.

CONCLUSION

Postpartum hemorrhage and related risk factors increased over a 20-year period. Despite the increased postpartum hemorrhage rates, blood transfusions, and hysterectomy rates decreased in recent years.

Optimizing systems to manage postpartum hemorrhage

Systems to optimize the management of postpartum hemorrhage must ensure timely diagnosis, rapid hemodynamic and hemostatic resuscitation, and prompt interventions to control the source of bleeding. None of these objectives can be effectively completed by a single clinician, and the management of postpartum hemorrhage requires a carefully coordinated interprofessional team. This article reviews systems designed to standardize hemorrhage diagnosis and response.

Procedural techniques to control postpartum hemorrhage

Postpartum hemorrhage can occur unexpectedly and with high dynamics. The mother's life often depends on quick action and good communication within an interdisciplinary team. Knowledge of each other's therapeutic options plays a major role. Treatment procedures include obstetric, surgical, and radiologic techniques. In addition to availability and experience with the techniques, two important aspects must be considered in the selection process: the type of delivery and the cause of the hemorrhage. In particular, the distinction between pregnancies with or without disturbed placentation from the placenta accreta spectrum is crucial. From these two points of view, we discuss here different uterus-preserving and uterus-removing techniques. We describe in detail the advantages and disadvantages of each procedure. Because most therapeutic options are based on small case series and uncontrolled studies, local circumstances and physician experience are critical in setting internal standards.

Obstetric hemorrhage: effective methods for addressing the menace in Sub-Saharan Africa

Obstetric hemorrhage is a serious emergency. It can occur late in pregnancy and in the immediate postpartum period. Postpartum hemorrhage is the major contributor of maternal deaths worldwide. The incidence of PPH-associated death across the African continent is at least three times higher than in other regions of the world. About 17% of PPH result in severe morbidity, including significant organ impairment. Maternal death and disability have long-lasting negative consequences for children, families, and communities. There are considerable variations across regions with for instance PPH accounting for about 8.0% of maternal deaths in developed countries compared to 19.7% in the developing countries. This disparity suggests that the majority of lives lost from PPH are preventable. Instituting primary preventive measures, prenatal care, comprehensive antenatal care, understanding the concept of birth preparedness and complication readiness, skilled birth attendant at delivery, avoiding delays, availability of comprehensive emergency obstetric care (CEmOC), good political will and disseminating the information on maternal mortality from PPH to the community are among key elements necessary to address the menace of PPH in developing countries. The aim of this review is to highlight the contributions of obstetric hemorrhage as a significant cause of maternal morbidity and mortality and suggest measures of prevention.

Comparison of European recommendations about patient blood management in postpartum haemorrhage

Postpartum haemorrhage (PPH) is the leading cause of maternal mortality and morbidity worldwide. Some documents with practical recommendations for the management of PPH do not include the most updated directives. This review offers a quality comparison of the recommendations stated in Europe since 2015. A literature search was conducted to identify the documents published in Europe from 2015 to 2020 containing recommendations about management of PPH. The search returned 10 publications. A narrative synthesis and a summary of the information about PPH definition and its management were performed. Differences in the definition of PPH were identified: some documents considered the delivery procedure, and many publications included severity criteria. The therapeutic goal for red blood cells transfusion ranged from 6 to 9 g/dl. There were divergences in the need for considering haemostatic results before fresh frozen plasma transfusion. The therapeutic goal of platelet transfusion ranged from 50 x 10⁹ to 100 x 10⁹  μ/L. There was a wide consensus about the therapeutic goal of fibrinogen replacement (>2 g/L), but not about its use in an unmonitored or pre-emptive manner. Most publications included therapeutic approaches such as tranexamic acid and recombinant factor VII activated, but not prothrombin complex concentrate or coagulation factor XIII. The recommendations about PPH management offered in European documents are heterogeneous and have changed over time. The standardisation of all them could be useful to make progress in PPH clinical management and research which, in turn, could strongly impact in patient outcomes.

Tranexamic acid administered during cesarean delivery in high-risk patients: maternal pharmacokinetics, pharmacodynamics, and coagulation status

BACKGROUND

Tranexamic acid is frequently administered for postpartum hemorrhage. The World Health Organization recommends 1 g intravenous dosing, repeated once after 30 minutes for ongoing bleeding. Understanding the pharmacokinetics and pharmacodynamics of tranexamic acid in patients at high risk of postpartum hemorrhage may enable dosage tailoring for optimal antifibrinolysis with minimal adverse events, such as thrombosis or renal cortical necrosis.

OBJECTIVE

This study aimed to report tranexamic acid pharmacokinetics and pharmacodynamics after 1 g intravenous dosing during cesarean delivery in patients at risk of hemorrhage. The primary endpoint was tranexamic acid plasma concentration of >10 μg/mL, known to inhibit 80% of fibrinolysis. In addition, the correlation between patient demographics and rotational thromboelastometry coagulation changes were analyzed.

STUDY DESIGN

In this prospective study, 20 women aged 18 to 50 years, ≥23 weeks of gestation undergoing cesarean delivery with at least 1 major (placenta previa, suspected placenta accreta spectrum, or active bleeding) or 2 minor (≥2 previous cesarean deliveries, previous postpartum hemorrhage, chorioamnionitis, polyhydramnios, macrosomia, obesity, or suspected placental abruption) risk factors for postpartum hemorrhage were recruited. The exclusion criteria were allergy to tranexamic acid, inherited thrombophilia, previous or current thrombosis, seizure history, renal or liver dysfunction, anticoagulation, or category III fetal heart tracing. Tranexamic acid 1 g was administered after umbilical cord clamping. Blood samples were drawn at 3, 7, 15, and 30 minutes and then at 30-minute intervals up to 5 hours. Plasma concentrations were evaluated as mean (standard error). Serial rotational thromboelastometry was performed and correlated with tranexamic acid plasma concentrations.

RESULTS

The median age of participants was 37.5 years (interquartile range, 35.0-39.5), and the median body mass index was 28.6 kg/m2 (interquartile range, 24.9-35.0). The median blood loss (estimated or quantitative) was 1500 mL (interquartile range, 898.5-2076.0). Of note, 9 of 20 (45%) received a transfusion of packed red blood cells. The mean peak tranexamic acid plasma concentration at 3 minutes was 59.8±4.7 μg/mL. All patients had a plasma concentration >10 μg/mL for 1 hour after infusion. Plasma concentration was >10 μg/mL in more than half of the patients at 3 hours and fell <10 μg/mL in all patients at 5 hours. There was a moderate negative correlation between body mass index and the plasma concentration area under the curve (r=-0.49; 95% confidence interval, -0.77 to -0.07; P=.026). Rotational thromboelastometry EXTEM maximum clot firmness had a weak positive correlation with longitudinal plasma concentration (r=0.32; 95% confidence interval, 0.21-0.46; P<.001). EXTEM maximum clot lysis was 0% after infusion in 18 patients (90%), and no patient in the study demonstrated a maximum lysis of >15% at any interval from 3 minutes to 5 hours. There was no significant correlation between EXTEM clot lysis at 30 minutes and longitudinal tranexamic acid plasma concentrations (r=0.10; 95% confidence interval, -0.20 to 0.19; P=.252).

CONCLUSION

After standard 1 g intravenous dosing of tranexamic acid during cesarean delivery in patients at high risk of hemorrhage, a plasma concentration of ≥10 μg/mL was sustained for at least 60 minutes. Plasma tranexamic acid levels correlated inversely with body mass index. The concurrent use of rotational thromboelastometry may demonstrate tranexamic acid's impact on clot firmness but not a hyperfibrinolysis-derived trigger for therapy.

Risk factors and recurrence of cause-specific postpartum hemorrhage: A population-based study

OBJECTIVE

To explore risk profiles of the different types of postpartum hemorrhage (PPH >500ml or severe PPH >1500ml) and their recurrence risks in a subsequent delivery.

METHODS

With data from The Medical Birth Registry of Norway and Statistics Norway we performed a population-based cohort study including all singleton deliveries in Norway from 1967-2017. Multilevel logistic regression was used to calculate odds ratio (OR), with 95% confidence interval (CI), with different PPH types (PPH >500ml or PPH >1500ml (severe PPH) combined with retained placenta, uterine atony, obstetric trauma, dystocia, or undefined cause) as outcomes.

RESULT

We identified 277 746 PPH cases of a total of 3 003 025 births (9.3%) from 1967 to 2017. Retained placenta (and/or membranes) was most often registered as severe PPH (29.3%). Maternal, fetal, and obstetric characteristics showed different associations with the PPH types. Male sex of the neonate was associated with reduced risk of PPH. This effect was strongest on PPH due to retained placenta (adjusted OR, (aOR): 0.80, 95% CI 0.78-0.82), atony (aOR 0.92, 95% CI: 0.90-0.93) and PPH with undefined cause (aOR 0.96, 95% CI: 0.95-0.97). Previous cesarean section showed a strong association with PPH due to dystocia (aOR of 13.2, 95% CI: 12.5-13.9). Recurrence risks were highest for the same type: PPH associated with dystocia (aOR: 6.8, 95% CI: 6.3-7.4), retained placenta and/or membranes (aOR: 5.9, 95% CI: 5.5-6.4), atony (aOR: 4.0, 95% CI: 3.8-4.2), obstetric trauma (aOR: 3.9, 95% CI: 3.5-4.3) and PPH of undefined cause (aOR: 2.2, 95% CI: 2.1-2.3).

CONCLUSION

Maternal, fetal and obstetric characteristics had differential effects on types of PPH. Recurrence differed considerably between PPH types. Retained placenta was most frequently registered with severe PPH, and showed strongest effect of sex; delivery of a boy was associated with lower risk of PPH. Previous cesarean increased the risk of PPH due to dystocia.