Obstetric Hemorrhage: Prevention, Recognition, and Treatment

Perinatal complications of the maternal-Fetal dyad in primiparous women subjected to vaginal delivery versus elective cesarean section: A retrospective study of clinical results associated with bioethical precepts

The obstetrics field is undergoing transformation and committing to ensuring the autonomy of pregnant women in decisions related to birth based on scientific information. The physiological process of birth typically results in vaginal delivery, but medicine has evolved to include obstetric surgeries that are safe and result in few perioperative complications, especially when cesarean section is performed from 39 weeks of gestational age. Thus, the question is whether clinicians should interfere with pregnant women's freedom to choose their mode of delivery by trying to persuade them to choose vaginal delivery. The objective was to analyze the perinatal complications of the maternal-fetal dyad in primiparous women subjected to vaginal delivery versus elective cesarean section with respect to the bioethical precepts of autonomy, beneficence and nonmaleficence. In total, 2,507 women, including 1,807 (72.1%) with vaginal deliveries and 700 (27.9%) with cesarean deliveries, were analyzed between 2017 and 2020. There was no difference between the types of delivery in maternal readmission, death, admission to the intensive care unit, an Apgar score <7 in the 5th minute of life, maternal blood transfusion or comorbidities of the mothers or newborns. The elective cesarean section group showed less need for therapeutic uterotonics. In primigravidae, it was observed that elective cesarean section did not present a higher risk of complications than vaginal delivery. Therefore, this guarantees the autonomy and right of the individual to choose the mode of delivery.

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.

Efficacy of resuscitative infusion with hemoglobin vesicles in rabbits with massive obstetric hemorrhage

BACKGROUND

Hemoglobin vesicles have been developed as artificial oxygen carriers, and they have the potential to serve as a substitute for red blood cell transfusion.

OBJECTIVE

This study aimed to evaluate the efficacy of hemoglobin vesicle infusion for the initial treatment instead of red blood cell transfusion in rabbits with massive obstetric hemorrhage.

STUDY DESIGN

Pregnant New Zealand white rabbits (28th day of pregnancy; normal gestation period, 29-35 days) underwent uncontrolled hemorrhage to induce shock by transecting the right midartery and concomitant vein in the myometrium. Subsequently, rabbits received isovolemic fluid resuscitation through the femoral vein with an equivalent volume of hemorrhage every 5 minutes. Resuscitative infusion regimens included 5% human serum albumin (n=6), stored washed red blood cells with plasma (vol/vol=1:1; n=5), and hemoglobin vesicle with 5% human serum albumin (vol/vol=4:1; n=5). A total of 60 minutes after the start of bleeding, rabbits underwent surgical hemostasis by ligation of the bleeding vessels and then were monitored for survival within 24 hours.

RESULTS

During fluid resuscitation, hemoglobin vesicle infusion and red blood cell transfusion maintained a mean arterial pressure of >50 mm Hg and a hemoglobin concentration of >9 g/dL and prevented the elevation of plasma lactate. In contrast, resuscitation with 5% human serum albumin alone could not prevent hemorrhagic shock as evidenced by a low mean arterial pressure (40 mm Hg), a low hemoglobin concentration (2 g/dL), and a marked elevation of plasma lactate. All animals in the red blood cell group and the hemoglobin vesicle group survived more than 8 hours, whereas all animals in the 5% human serum albumin group died within 8 hours.

CONCLUSION

Hemoglobin vesicle infusion may be effective in the initial management of massive obstetric hemorrhage.

Uterine artery embolization versus hysterectomy in the treatment of refractory postpartum hemorrhage: a systematic review and meta-analysis

Introduction: We carried out a systematic review and meta-analysis to assess the safety and effectiveness of uterine artery embolization (UAE) compared with conventional hysterectomy on refractory postpartum hemorrhage (PPH).Methods: We searched PubMed, Embase, Chinese National Knowledge Infrastructure database (CNKI), Cochrane Library, and Wanfang database through October 2017 for randomized controlled trials (RCTs) and observational studies assessing the safety and effectiveness of UAE compared with hysterectomy on refractory PPH. The main outcome measures included the blood loss, operating time, hemostatic effective rate, and length of stay.Results: Six RCTs and nine observational studies were included in the meta-analysis, which involved 1142 women with refractory PPH. The results demonstrated that UAE was more beneficial on refractory PPH compared with hysterectomy using four scales: blood loss (WMD 893.39 mL; 95% CI: -1205.65, -581.13; p < .001); operating time (WMD -37.19 minutes; 95% CI: -44.42, -29.96; p < .001); length of stay (WMD -5.36 days; 95% CI: -5.76, -4.97; p < .001), hemostatic effective rate (OR 1.58, 95% CI: 0.80, 3.12, p = .184) .Conclusions: In the present meta-analysis, the positive findings suggest UAE has beneficial effects on refractory PPH. UAE significantly reduced blood loss, shortened the operating time, and length of stay compared with hysterectomy. And there is no difference between the UAE group and hysterectomy group in hemostatic effective rate. However, those findings should be treated with caution because of heterogeneity and potential biases.