Higher Plasma Myo-Inositol in Pregnancy Associated with Reduced Postpartum Blood Loss: Secondary Analyses of the NiPPeR Trial.

We previously reported that a combined myo-inositol, probiotics, and enriched micronutrient supplement (intervention) taken preconception and in pregnancy reduced postpartum blood loss (PBL) and major postpartum hemorrhage compared with a standard micronutrient supplement (control), as secondary outcomes of the NiPPeR trial. This study aimed to identify the intervention components that may contribute to this effect. Associations of plasma concentrations of myo-inositol and vitamins B2, B6, B12, and D at preconception (before and after supplementation), early (~7-weeks), and late pregnancy (~28-weeks) with PBL were assessed by multiple linear regression, adjusting for site, ethnicity, preconception BMI, parity, and previous cesarean section. Amongst 583 women, a higher concentration of myo-inositol in early pregnancy was associated with a PBL reduction [ßadj -1.26 (95%CI -2.23, -0.29) mL per µmol/L myo-inositol increase, p = 0.011]. Applying this co-efficient to the increase in mean 7-week-myo-inositol concentration of 23.4 µmol/L with the intervention equated to a PBL reduction of 29.5 mL (~8.4% of mean PBL of 350 mL among controls), accounting for 84.3% of the previously reported intervention effect of 35 mL. None of the examined vitamins were associated with PBL. Therefore, myo-inositol may be a key intervention component mediating the PBL reduction. Further work is required to determine the mechanisms involved.

Prediction of post-delivery hemoglobin levels with machine learning algorithms.

Predicting postpartum hemorrhage (PPH) before delivery is crucial for enhancing patient outcomes, enabling timely transfer and implementation of prophylactic therapies. We attempted to utilize machine learning (ML) using basic pre-labor clinical data and laboratory measurements to predict postpartum Hemoglobin (Hb) in non-complicated singleton pregnancies. The local databases of two academic care centers on patient delivery were incorporated into the current study. Patients with preexisting coagulopathy, traumatic cases, and allogenic blood transfusion were excluded from all analyses. The association of pre-delivery variables with 24-h post-delivery hemoglobin level was evaluated using feature selection with Elastic Net regression and Random Forest algorithms. A suite of ML algorithms was employed to predict post-delivery Hb levels. Out of 2051 pregnant women, 1974 were included in the final analysis. After data pre-processing and redundant variable removal, the top predictors selected via feature selection for predicting post-delivery Hb were parity (B: 0.09 [0.05-0.12]), gestational age, pre-delivery hemoglobin (B:0.83 [0.80-0.85]) and fibrinogen levels (B:0.01 [0.01-0.01]), and pre-labor platelet count (B*1000: 0.77 [0.30-1.23]). Among the trained algorithms, artificial neural network provided the most accurate model (Root mean squared error: 0.62), which was subsequently deployed as a web-based calculator: https://predictivecalculators.shinyapps.io/ANN-HB . The current study shows that ML models could be utilized as accurate predictors of indirect measures of PPH and can be readily incorporated into healthcare systems. Further studies with heterogenous population-based samples may further improve the generalizability of these models.

An in vitro study of coagulation evaluation in obstetric hemorrhage for pregnancy-induced hypertension with coagulation and platelet function analyzer.

This study aimed to establish in vitro hemodilution and resupplementation assays for obstetric hemorrhage in pregnancy-induced hypertension (PIH) and to monitor the coagulation function dynamically using a coagulation and platelet function analyzer. Forty-seven singleton pregnant women were divided into normal (n = 24) and PIH (n = 23) groups. Peripheral blood samples were used to construct the assays, and the activated clotting time (ACT), clotting rate (CR), and platelet function index (PF) were measured. The results showed that the baseline ACT was higher in the PIH group (p < 0.01). Hemodilution assays showed decreased ACT and increased CR and PF, with ACT changes significantly lower in the PIH group (p < 0.05). CR changed most in both groups at lower dilution ratios (35% to 50%), while ACT changed most at a higher dilution ratio (75%). In the resupplementation assay, ACT exhibited the most significant response. The analyzer effectively detected differences between pregnant women with and without PIH. Thus, we need to pay more attention to the changes of ACT in the actual clinical application to assess the coagulation status of parturients.

The value of fibrinogen combined with D-dimer and neonatal weight in predicting postpartum hemorrhage in vaginal delivery.

OBJECTIVES: The purpose of this study was to explore whether fibrinogen (Fib) can be used as a predictor of postpartum hemorrhage (PPH) in parturients with vaginal delivery, and the value of combining Fib with other indexes to predict postpartum hemorrhage in vaginal delivery. METHODS: A total of 207 parturients who delivered via vagina were divided into PPH group (n=102) and non-PPH group (n=105). The PPH group was further divided into mild PPH group and severe PPH group. The differences of Fib, platelet (PLT), mean platelet volume (MPV), platelet distribution width (PDW), D-dimer (D-D), hemoglobin (HGB) and neonatal weight (Nw) between the two groups were compared to explore the significance of these indexes in predicting PPH. RESULTS: Fib, PLT and PDW in PPH group were significantly lower than those in non-PPH group, while D-D and Nw in PPH group were significantly higher than those in non-PPH group. In the binary logistic regression model, we found that Fib, D-D and Nw were independently related to PPH. The risk of PPH increased by 9.87 times for every 1 g/L decrease in Fib. The cut-off value of Fib is 4.395 (sensitivity 0.705, specificity 0.922). The AUC value of PPH predicted by Fib combined with D-D and Nw was significantly higher than that of PPH predicted by Fib (p<0.05, 95 % CI 0.00313-0.0587). CONCLUSIONS: Fib, D-D and Nw have good predictive value for PPH of vaginal delivery, among which Fib is the best. The combination of three indexes of Fib, D-D and Nw can predict PPH more systematically and comprehensively, and provide a basis for clinical prevention and treatment of PPH.

Tranexamic Acid to Prevent Obstetrical Hemorrhage after Cesarean Delivery.

BACKGROUND: Prophylactic use of tranexamic acid at the time of cesarean delivery has been shown to decrease the calculated blood loss, but the effect on the need for blood transfusions is unclear. METHODS: We randomly assigned patients undergoing cesarean delivery at 31 U.S. hospitals to receive either tranexamic acid or placebo after umbilical-cord clamping. The primary outcome was a composite of maternal death or blood transfusion by hospital discharge or 7 days post partum, whichever came first. Key secondary outcomes were estimated intraoperative blood loss of more than 1 liter (prespecified as a major secondary outcome), interventions for bleeding and related complications, the preoperative-to-postoperative change in the hemoglobin level, and postpartum infectious complications. Adverse events were assessed. RESULTS: A total of 11,000 participants underwent randomization (5529 to the tranexamic acid group and 5471 to the placebo group); scheduled cesarean delivery accounted for 50.1% and 49.2% of the deliveries in the respective groups. A primary-outcome event occurred in 201 of 5525 participants (3.6%) in the tranexamic acid group and in 233 of 5470 (4.3%) in the placebo group (adjusted relative risk, 0.89; 95.26% confidence interval [CI], 0.74 to 1.07; P = 0.19). Estimated intraoperative blood loss of more than 1 liter occurred in 7.3% of the participants in the tranexamic acid group and in 8.0% of those in the placebo group (relative risk, 0.91; 95% CI, 0.79 to 1.05). Interventions for bleeding complications occurred in 16.1% of the participants in the tranexamic acid group and in 18.0% of those in the placebo group (relative risk, 0.90; 95% CI, 0.82 to 0.97); the change in the hemoglobin level was -1.8 g per deciliter and -1.9 g per deciliter, respectively (mean difference, -0.1 g per deciliter; 95% CI, -0.2 to -0.1); and postpartum infectious complications occurred in 3.2% and 2.5% of the participants, respectively (relative risk, 1.28; 95% CI, 1.02 to 1.61). The frequencies of thromboembolic events and other adverse events were similar in the two groups. CONCLUSIONS: Prophylactic use of tranexamic acid during cesarean delivery did not lead to a significantly lower risk of a composite outcome of maternal death or blood transfusion than placebo. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development; ClinicalTrials.gov number, NCT03364491.).

Point-of-Care Viscoelastic Tests in the Management of Obstetric Hemorrhage.

Obstetric hemorrhage remains the leading cause of maternal morbidity and mortality worldwide. Thromboelastography and rotational thromboelastometry are laboratory methods of assessing the kinetics of blood clot formation through real-time measurement of viscoelastic clot strength and may aid in management of severe hemorrhage. Although first described more than 70 years ago, viscoelastic testing devices are now available that allow for rapid point-of-care use of this technology to aid in real-time management of blood product replacement in cases of severe hemorrhage. These devices can be used to visually estimate multiple facets of hemostasis-coagulation, platelet function, and fibrinolysis-within 10-20 minutes. They have been used successfully in cardiac surgery, trauma, and liver transplantation and have potential for use in management of obstetric hemorrhage. Goals with their use include targeted transfusion of blood and its components for specific coagulation deficiencies. To date, however, published experiences with the use of these viscoelastic tests for obstetric hemorrhage have been limited. Because of the increasing use of the point-of-care tests by anesthesiologists, surgeons, and intensivists, the purpose of this report is to familiarize obstetricians with the technology involved and its use in severe hemorrhage complicating pregnancy.

Delta neutrophil index and shock index can stratify risk for the requirement for massive transfusion in patients with primary postpartum hemorrhage in the emergency department.

BACKGROUND: Postpartum hemorrhage (PPH) constitutes a major risk for maternal mortality and morbidity. Unfortunately, the severity of PPH can be underestimated because it is difficult to accurately measure blood loss by visual estimation. The delta neutrophil index (DNI), which reflects circulating immature granulocytes, is automatically calculated in hematological analyzers. We evaluated the significance of the DNI in predicting hemorrhage severity based on the requirement for massive transfusion (MT) in patients with PPH. METHODS: We retrospectively analyzed data from a prospective registry to evaluate the association between the DNI and MT. Moreover, we assessed the predictive ability of the combination of DNI and shock index (SI) for the requirement for MT. MT was defined as a transfusion of ≥10 units of red blood cells within 24 h of PPH. In total, 278 patients were enrolled in this study and 60 required MT. RESULTS: Multivariable logistic regression revealed that the DNI and SI were independent predictors of MT. The optimal cut-off values of ≥3.3% and ≥1.0 for the DNI and SI, respectively, were significantly associated with an increased risk of MT (DNI: positive likelihood ratio [PLR] 3.54, 95% confidence interval [CI] 2.5-5.1 and negative likelihood ratio [NLR] 0.48, 95% CI 0.4-0.7; SI: PLR 3.21, 95% CI 2.4-4.2 and NLR 0.31, 95% CI 0.19-0.49). The optimal cut-off point for predicted probability was calculated for combining the DNI value and SI value with the equation derived from logistic regression analysis. Compared with DNI or SI alone, the combination of DNI and SI significantly improved the specificity, accuracy, and positive likelihood ratio of the MT risk. CONCLUSION: The DNI and SI can be routinely and easily measured in the ED without additional costs or time and can therefore, be considered suitable parameters for the early risk stratification of patients with primary PPH.

The association of antenatal D-dimer and fibrinogen with postpartum hemorrhage and intrauterine growth restriction in preeclampsia.

BACKGROUND: D-dimer and fibrinogen were verified to be altered in preeclampsia. This study was to evaluate the associations of D-dimer and fibrinogen plasma levels with postpartum hemorrhage or intrauterine growth restriction in preeclamptic women. METHODS: This was a retrospective study that recruited 278 preeclamptic women with singleton pregnancy from January 2016 to December 2019. Patients were allocated into five groups: mild preeclampsia (mPE) (n=68), mild preeclampsia with postpartum hemorrhage (mPE+PPH) (n=13), severe preeclampsia (sPE) (n=112), severe preeclampsia with postpartum hemorrhage (sPE+PPH) (n=17) and severe preeclampsia with intrauterine growth restriction (sPE+IUGR) (n=68). The antenatal D-dimer and fibrinogen plasma levels were analyzed among the groups. Logistic regression was used to determine the correlation between serum indexes and PPH or IUGR in preeclampsia. RESULTS: The antenatal D-dimer plasma levels were significantly higher in the sPE+PPH group than that in the sPE group (2.02 µg/ml versus 1.37 µg/ml, P = 0.001), but there was no difference in fibrinogen. Elevated D-dimer was associated with PPH among severe preeclamptic women (adjusted odds ratio (aOR) [95% CI]: 3.093 [1.527-6.264], P = 0.002). No differences in D-dimer and fibrinogen were found between the mPE and mPE+PPH groups or between the sPE and sPE+IUGR groups. CONCLUSIONS: Elevated antenatal plasma D-dimer level may be associated with postpartum hemorrhage in severe preeclampsia, but not with intrauterine growth restriction. Future prospective clinical trials are needed to investigate the predictive value of D-dimer in postpartum hemorrhage in severe preeclampsia.

Effects of rotational thromboelastometry-guided transfusion management in patients undergoing surgical intervention for postpartum hemorrhage: An observational study.

BACKGROUND: Postpartum hemorrhage (PPH) can be associated with coagulopathy, which may be difficult to rapidly assess and may exacerbate blood loss. Rotational thromboelastometry (ROTEM) at the point of care can guide clinician choice of blood products and has been shown in some settings to reduce transfusions and improve outcomes. This hospital-based observational study aims to measure effects of a ROTEM-guided transfusion protocol on transfusion practice and clinical outcomes in patients with PPH managed in the operating theater. STUDY DESIGN AND METHODS: We compared a retrospective cohort of 450 consecutive patients with PPH treated in the operating theater before the introduction of a ROTEM-guided transfusion algorithm in June 2016, with 450 patients treated after its introduction. Multivariate regression was used to evaluate the effect of ROTEM introduction on the primary outcome, patients requiring a packed red blood cell (PRBC) transfusion and adjusting for demographic and obstetric confounders. Secondary outcomes included other blood product transfusions, hysterectomy, and intensive care unit admission. RESULTS: A total of 90 (20%) of patients treated prior to ROTEM introduction received a PRBC transfusion, compared with 102 (22.7%) of those treated after ROTEM introduction (95% confidence interval [CI] 1.0-2.0, p = .04). There was no difference in PRBC transfusion in patients undergoing caesarean section (95% CI 0.5-1.8, p = .99). There was a trend toward increased use of cryoprecipitate and reduced use of platelets and fresh frozen plasma after ROTEM introduction. CONCLUSION: In our institution, the introduction of ROTEM-guided transfusion did not reduce PRBC transfusion in patients with PPH treated in the operating theater.

Complement activation and blockade in massive post-partum haemorrhage, thrombotic microangiopathy and acute kidney injury: a case report.

BACKGROUND: Thrombotic microangiopathy (TMA)-mediated acute kidney injury (AKI) following massive haemorrhage is a rare but severe complication of the post-partum period. It is associated with a poor renal prognosis and a high risk of end-stage kidney disease. Complement activation may occur in this picture. However, whether complement activation, and thus complement blockade, may be critically relevant in this setting is unknown. CASE PRESENTATION: A 50 year-old woman presented with massive delayed post-partum haemorrhage (PPH). Despite bleeding control and normalization of coagulation parameters, she rapidly developed AKI stage 3 associated with dysmorphic microhematuria and proteinuria up to 2 g/day with the need of renal replacement therapy. Blood tests showed signs of TMA associated with markedly increased sC5b-9 and factor Bb plasma levels, respectively markers of terminal and alternative complement pathway over-activation. This clinical picture prompted us to initiate anti-C5 therapy. sC5b-9 normalized within 12 h after the first dose of eculizumab, factor Bb and C3 after seven days, platelet count after nine days and haptoglobin after 3 weeks. The clinical picture improved rapidly with blood pressure control within 48 h. Diuresis resumed after three days, kidney function rapidly improved and haemodialysis could be discontinued after the sixth and last dose. Serum creatinine returned to normal two years after presentation. CONCLUSIONS: We suggest that massive PPH induced major activation of complement pathways, which ultimately lead to TMA-induced AKI. Various causes, such as oocyte-donation, the potential retention of placental material and the use of tranexamic acid may have contributed to complement activation due to PPH. The prompt administration of anti-C5 therapy may have rapidly restored kidney microcirculation patency, thus reversing signs of TMA and AKI. We propose that complement activation may represent a major pathophysiological player of this complication and may provide a novel therapeutic avenue to improve renal prognosis in TMA-induced AKI following massive PPH.

Analysis of perinatal coagulation function in preeclampsia.

ABSTRACT: To study the dynamic changes in perinatal coagulation function in patients with preeclampsia (PE).The general data and coagulation indexes of 290 PE patients during the perinatal period (prenatal and 1 and 3 days postpartum) and 256 healthy pregnant women in the third trimester of pregnancy were investigated, and the data were analyzed.Compared with healthy pregnant women, prothrombin time (PT), fibrinogen (FIB), platelet count (PLT), mean platelet volume (MPV), thrombocytocrit (PCT), maximum amplitude (MA), and coagulation index (CI) of PE patients decreased, and activated partial thrombin time (APTT), thrombin time (TT), D-dimer (DD), platelet distribution width (PDW) and K values increased before delivery (P < .05). APTT and FIB in PE patients were lower in the day 1 postpartum group than in the prenatal and postpartum day 3 groups, and TT, DD, and fibrin degradation products (FDP) were higher (P < .05). PCT and MPV were highest in the prenatal group (P < .05).Compared with that of healthy pregnant women, the coagulation function of PE patients is in a relatively low-coagulation and high-fibrinolysis state on postpartum day 1, which increases the risk of postpartum hemorrhage and other adverse outcomes.

Effect of hypofibrinogenemia on obstetrical disseminated intravascular coagulation in Japan in 2018: a multicenter retrospective cohort study.

Japanese obstetrical hemorrhage recommendations state that not only pregnant women with an obstetrical disseminated intravascular coagulation (DIC) score ≥ 8 points but also those with fibrinogen levels ≤ 1.5 g/L have a high risk of maternal death and warrant blood transfusion. Our aim was to demonstrate the potential of fibrinogen levels ≤ 1.5 g/L as predictors of a Japanese obstetrical DIC score of ≥ 8. We included 595 participants with blood loss ≥ 1000 mL during vaginal delivery or ≥ 2000 mL during cesarean delivery. The frequency and volume of red blood cell (RBC), fresh-frozen plasma, platelet concentrate (PC), and fibrinogen administration in women with a DIC score of ≥ 8 and fibrinogen levels of ≤ 1.5 g/L were significantly higher than controls (P < 0.0001). Multivariate analysis demonstrated that a score of ≥ 3 was associated with RBC or fibrinogen administration and a score of ≥ 5 was associated with PC transfusion. Fibrinogen levels ≤ 1.89 g/L and ≤ 2.44 g/L were associated with PC transfusion and fibrinogen administration, respectively. Fibrinogen levels ≤ 1.5 g/L may have similar potential to a DIC score of ≥ 8 points for detecting obstetrical DIC in Japan.

Practical approach to transfusion management of post-partum haemorrhage.

OBJECTIVES: To describe transfusion management during post-partum haemorrhage (PPH) and the usefulness of standard or point-of-care (POC) laboratory tests for guiding haemostatic management. BACKGROUND: PPH is the leading cause of maternal mortality and severe maternal morbidity worldwide. Despite the efforts made in recent years, PPH is often burdened by preventable death. Recent data from the active Italian Obstetric Surveillance System (ItOSS) highlighted the following main critical issues: inadequate communication between healthcare professionals, inability to correctly and promptly assess the severity of haemorrhage, delays in diagnosis and treatment, failure to request blood promptly and inappropriate monitoring post-partum. MATERIALS AND METHODS: Data in the literature have been compared with the rotational thromboelastometry (ROTEM)- and the thromboelastography (TEG)-guided algorithms applied in the authors' departments. RESULTS: PPH transfusion therapy may have an empirical approach based on the standard use of blood products or a targeted approach based on coagulation monitoring by laboratory or POC tests. Here, the authors describe how they manage PPH in their departments, according to the Italian guidelines, along with the addition of a ROTEM- and a TEG-guided algorithms developed by themselves. CONCLUSION: Although the proposed algorithms have not been validated by trials or observational studies conducted in our departments, we believe that these indications could be useful for supporting clinical practice. Furthermore, we deem it appropriate to emphasise the importance of a multidisciplinary approach and the need for standardised and shared protocols to support the decisions of healthcare professionals.

Effective tranexamic acid concentration for 95% inhibition of tissue-type plasminogen activator-induced hyperfibrinolysis in full-term pregnant women: a prospective interventional study.

Postpartum haemorrhage is the leading cause of maternal mortality and morbidity worldwide. Tranexamic acid (TXA) has been shown to reduce blood loss and blood product transfusion requirements. Despite clinical evidence, further studies are needed to better define the pharmacokinetic and pharmacodynamic characteristics of TXA in pregnant women. The objective of our prospective observational ex-vivo study was to define the effective TXA concentration required to inhibit 95% (EC95) of tissue-type plasminogen activator (t-PA)-induced fibrinolysis in full-term pregnant women. Hyperfibrinolysis was induced by adding supraphysiologic concentration of t-PA to blood samples obtained from 30 full-term pregnant women and 10 healthy nonpregnant female volunteers. Increasing TXA concentrations (0--40 µg/ml) were then spiked into the blood samples and inhibition of fibrinolysis was assessed using the lysis index at 30 min of the ROTEM measured on EXTEM and NATEM tests. Effective TXA concentrations required to achieve EC95 were extrapolated using nonlinear regression. EC95 were compared between groups using an extra sum-of-squares F test. EC95 in pregnant women was 14.7 µg/ml (95% CI 12.4--17.5 µg/ml) on EXTEM and 11.2 µg/ml (95% CI 8.3--15.1 µg/ml) on NATEM tests. These values were significantly higher than those obtained in volunteers: 8.7 µg/ml (95% CI 5.5--13.9 µg/ml) and 6.8 µg/ml (95% CI 5.3--8.8 µg/ml), respectively (both P < 0.001). Our results suggest a higher fibrinolytic potential in pregnant women compared with nonpregnant women.

Point-of-care blood clotting test and its correlation with fibrinogen level: Potential in goal-directed transfusion in postpartum hemorrhage.

OBJECTIVE: To study the correlation of conventional point-of-care clotting test (POCCT) of whole blood with laboratory fibrinogen levels in women with primary major postpartum hemorrhage (PPH) to generate evidence regarding its potential in rationalizing transfusion of blood components for supplementing fibrinogen. METHODS: A total of 68 samples were studied: 40 from women with primary major PPH, 20 from women without PPH, and eight samples of Fresh Frozen Plasma (FFP). POCCT was performed in the PPH and non-PPH groups and at the same time, sample for laboratory fibrinogen was sent. Values were correlated using Pearson's correlation coefficient (r). Depending upon the laboratory fibrinogen values, POCCT in the PPH group was divided into three subgroups of less than 7, 7-11, and more than >11 min as subgroups 1, 2, and 3, respectively. RESULTS: Women in the PPH group (n = 40) had a mean fibrinogen level of 346.15 ± 143.37 mg% with a significant negative correlation with POCCT (r = -0.69, P < 0.001). Mean fibrinogen levels of non-PPH group and FFP samples were 602.1 ± 169.72 and 286.75 ± 103.42 mg%, respectively. PPH subgroups 1, 2, and 3 had mean fibrinogen of 452.2 ± 141.8, 332.58 ± 138.51, and 158.71 ± 145 mg%, respectively. These values may potentially guide FFP transfusions. CONCLUSION: POCCT is easy, costs nothing and has a potential role in rationalizing FFP transfusion in low- and middle-income countries.

Association between ionised calcium and severity of postpartum haemorrhage: a retrospective cohort study.

BACKGROUND: Postpartum haemorrhage (PPH) is often complicated by impaired coagulation. We aimed to determine whether the level of ionised calcium (Ca2+), an essential coagulation co-factor, at diagnosis of PPH is associated with bleeding severity. METHODS: This was a retrospective cohort study of women diagnosed with PPH during vaginal delivery between January 2009 and April 2020. Ca2+ levels at PPH diagnosis were compared between women who progressed to severe PPH (primary outcome) and those with less severe bleeding. Severe PPH was defined by transfusion of ≥2 blood units, arterial embolisation or emergency surgery, admission to ICU, or death. Associations between other variables (e.g. fibrinogen concentration) and bleeding severity were also assessed. RESULTS: For 436 patients included in the analysis, hypocalcaemia was more common among patients with severe PPH (51.5% vs 10.6%, P<0.001). In a multivariable logistic regression model, Ca2+ and fibrinogen were the only parameters independently associated with PPH severity with odds ratios of 1.14 for each 10 mg dl-1 decrease in fibrinogen (95% confidence interval [CI], 1.05-1.24; P=0.002) and 1.97 for each 0.1 mmol L-1 decrease in Ca2+ (95% CI, 1.25-3.1; P=0.003). The performance of Ca2+ or fibrinogen was not significantly different (area under the curve [AUC]=0.79 [95% CI, 0.75-0.83] vs AUC=0.86 [95% CI, 0.82-0.9]; P=0.09). The addition of Ca2+ to fibrinogen improved the model, leading to AUC of 0.9 (95% CI, 0.86-0.93), P=0.03. CONCLUSIONS: Ca2+ level at the time of diagnosis of PPH was associated with risk of severe bleeding. Ca2+ monitoring may facilitate identification and treatment of high-risk patients.

Early prognostic capacity of serum lactate for severe postpartum hemorrhage.

OBJECTIVE: To evaluate whether the concentration of serum lactate during the diagnosis of postpartum hemorrhage (bleeding ≥500 mL during labor or ≥1000 mL during cesarean delivery) predicts severe hemorrhage (SPPH; blood loss ≥1500 mL at end of labor or in the following 24 h). METHODS: A prospective cohort pilot study was conducted of women with a vaginal or cesarean delivery from February 2018 to March 2019 who presented with bleeding ≥500 mL measured by the gravimetric method in a reference hospital in San Luis Potosi, Mexico. Venous blood samples were taken for analysis of serum lactate. A receiver operating characteristic curve determined the serum lactate threshold value for SPPH and χ2 test assessed the difference in serum lactate elevation between SPPH and non-SPPH groups. Lastly, the prognostic capacity between the thresholds was compared. RESULTS: SPPH developed in 43.33% of the 30 women in the study group. The best prognostic threshold was 2.68 mmol/L of serum lactate (odds ratio [OR] 17.88, 95% confidence interval [CI] 2.7-16.8, P < 0.001); sensitivity was 0.85 (95% CI 0.55-0.98); specificity was 0.76 (95% CI 0.50-0.93). CONCLUSION: Serum lactate may be a useful prognostic marker for SPPH, more studies are needed to validate these findings.