Maternal Coagulation Disorders and Postpartum Hemorrhage

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.

Oxytocin receptor single nucleotide polymorphism predicts atony-related postpartum hemorrhage

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Viscoelastic Hemostatic Assays for Postpartum Hemorrhage

This article discusses the importance and effectiveness of viscoelastic hemostatic assays (VHAs) in assessing hemostatic competence and guiding blood component therapy (BCT) in patients with postpartum hemorrhage (PPH). In recent years, VHAs such as thromboelastography and rotational thromboelastometry have increasingly been used to guide BCT, hemostatic adjunctive therapy and prohemostatic agents in PPH. The three pillars of identifying hemostatic competence include clinical observation, common coagulation tests, and VHAs. VHAs are advantageous because they assess the cumulative contribution of all components of the blood throughout the entire formation of a clot, have fast turnaround times, and are point-of-care tests that can be followed serially. Despite these advantages, VHAs are underused due to poor understanding of correct technique and result interpretation, a paucity of widespread standardization, and a lack of large clinical trials. These VHAs can also be used in cases of uterine atony, preeclampsia, acute fatty liver of pregnancy, amniotic fluid embolism, placental abruption, genital tract trauma, surgical trauma, and inherited and prepartum acquired coagulopathies. There exists an immediate need for a point-of-care test that can equip obstetricians with rapid results on developing coagulopathic states. The use of VHAs in predicting and treating PPH, although in an incipient state, can fulfill this need.

Clinical analysis of emergency exploratory laparotomy in patients with intractable postpartum hemorrhage

Objective

This study was performed to explore the causes and clinical characteristics of emergency exploratory laparotomy in patients with intractable postpartum hemorrhage.

Methods

This retrospective study was performed from January 2004 to December 2017. Patients with intractable postpartum hemorrhage were grouped according to the initial pathogenesis as determined by exploratory laparotomy: uterine atony, placental factors, coagulation dysfunction, or uterine rupture.

Results

This study involved 72 patients who underwent emergency exploratory laparotomy, accounting for 0.04% of total deliveries. Uterine preservation surgery and hysterectomy were performed in 31 and 41 patients, respectively. Abnormal events upon returning to the ward were primarily vaginal hemorrhage and pelvic hematoma. The frequency of uterine artery ligation was lower in the hysterectomy group than uterine preservation group. The prothrombin activity level, fibrinogen level, and platelet count before surgery were lower in the hysterectomy group than uterine preservation group. The international normalized ratio and activated partial thromboplastin time were higher in the hysterectomy group than uterine preservation group. In total, 44 patients developed complications.

Conclusion

Placental implantation is a primary cause of hysterectomy after emergency laparotomy. However, the possibility of postpartum hemorrhage caused by coagulation disorders should not be ignored.

A global quantitative survey of hemostatic assessment in postpartum hemorrhage and experience with associated bleeding disorders

Purpose

Coagulopathy may be a serious complicating or contributing factor to postpartum hemorrhage (PPH), and should be promptly recognized to ensure proper bleeding management. This study aims to evaluate the approaches of obstetrician-gynecologists worldwide towards assessing massive PPH caused by underlying bleeding disorders.

Methods

A quantitative survey was completed by 302 obstetrician-gynecologists from 6 countries (the UK, France, Germany, Italy, Spain, and Japan). The survey included questions on the use of hematologic laboratory studies, interpretation of results, laboratory’s role in coagulation assessments, and experience with bleeding disorders.

Results

Overall, the most common definitions of “massive” PPH were >2,000 mL (39%) and >1,500 mL (34%) blood loss. The most common criteria for rechecking a “stat” complete blood count and for performing coagulation studies were a drop in blood pressure (73%) and ongoing visible bleeding (78%), respectively. Laboratory coagulation (prothrombin time/activated partial thromboplastin time [PT/aPTT]) and factor VIII/IX assays were performed on-site more often than were mixing studies (laboratory coagulation studies, 93%; factor VIII/IX assays, 63%; mixing studies, 22%). Most commonly consulted sources of additional information were colleagues within one’s own specialty (68%) and other specialists (67%). Most respondents had consulted with a hematologist (78%; least, Germany [56%]; greatest, UK [98%]). The most common reason for not consulting was hematologist unavailability (44%). The most commonly reported thresholds for concern with PT and aPTT were 13 to 20 seconds (36%) and 30 to 45 seconds (50%), respectively. Most respondents reported having discovered an underlying bleeding disorder (58%; least, Japan [35%]; greatest, Spain [74%]).

Conclusion

Global survey results highlight similarities and differences between countries in how PPH is assessed and varying levels of obstetrician-gynecologist experience with identification of underlying bleeding disorders and engagement of hematology consultants. Opportunities to improve patient management of PPH associated with bleeding disorders include greater familiarity with interpreting PT/aPTT test results and identification of and consistent consultation with hematologists with relevant expertise.

Extravasating uterine pseudoaneurysm: A rare cause of postpartum haemorrhage

Postpartum haemorrhage (PPH) remains one of the leading causes of maternal death worldwide and can be classified as either immediate (primary) or delayed (secondary) according to the onset time - before or after 24 hours postpartum. Uterine pseudoaneurysm is a rare cause of PPH that has been suggested to arise from abnormal vascular regression and a recurrent vascular healing state, such as a vascular stricture and relaxation with thrombin deposits after placental expulsion. With advances in multidetector computed tomography, 3D-computed tomography with angiography can aid in identifying the location and originating vessels of the pseudoaneurysm via fast and clear 3D images. Once a bleeding pseudoaneurysm is diagnosed as the cause of PPH, conservative management is frequently unsuccessful in controlling bleeding. Transcatheter uterine arterial embolisation appears to be the treatment of choice in haemodynamically stable women.

Hemostatic assessment, treatment strategies, and hematology consultation in massive postpartum hemorrhage: results of a quantitative survey of obstetrician-gynecologists

Objective

To assess potential diagnostic and practice barriers to successful management of massive postpartum hemorrhage (PPH), emphasizing recognition and management of contributing coagulation disorders.

Study design

A quantitative survey was conducted to assess practice patterns of US obstetrician-gynecologists in managing massive PPH, including assessment of coagulation.

Results

Nearly all (98%) of the 50 obstetrician-gynecologists participating in the survey reported having encountered at least one patient with “massive” PPH in the past 5 years. Approximately half (52%) reported having previously discovered an underlying bleeding disorder in a patient with PPH, with disseminated intravascular coagulation (88%, n=23/26) being identified more often than von Willebrand disease (73%, n=19/26). All reported having used methylergonovine and packed red blood cells in managing massive PPH, while 90% reported performing a hysterectomy. A drop in blood pressure and ongoing visible bleeding were the most commonly accepted indications for rechecking a “stat” complete blood count and coagulation studies, respectively, in patients with PPH; however, 4% of respondents reported that they would not routinely order coagulation studies. Forty-two percent reported having never consulted a hematologist for massive PPH.

Conclusion

The survey findings highlight potential areas for improved practice in managing massive PPH, including earlier and more consistent assessment, monitoring of coagulation studies, and consultation with a hematologist.