Carbetocin versus oxytocin for the prevention of postpartum haemorrhage following caesarean section: the results of a double-blind randomised trial

Intramyometrial and intravenous oxytocin compared to intravenous carbetocin for prevention of postpartum hemorrhage in elective cesarean section-A quasi-randomized controlled phase IV non-inferiority interventional trial

INTRODUCTION

Our objective was to assess non-inferiority of the unique approach used in our institution of combined 10 IU IM (intramyometrial) and 10 IU IV (intravenous) oxytocin to carbetocin IV in preventing severe postpartum blood loss in elective cesarean sections. The design was a prospective controlled phase IV non-inferiority interventional trial. The setting was a tertiary center at University Hospital, Zurich, Switzerland.

MATERIAL AND METHODS

The population consisted of 550 women undergoing elective cesarean section after 36 completed weeks of gestation at low risk for postpartum hemorrhage (PPH). Participants were assigned to either combined oxytocin regimen (10 IU IM and 10 IU IV) or carbetocin (100 μg IV). Non-inferiority for oxytocin for severe PPH was assessed with a 0.05 margin using the Newcombe-Wilson score method. The main outcome measures were severe postpartum blood loss defined as delta hemoglobin (∆Hb, Hb prepartum-Hb postpartum) ≥30 g/L.

RESULTS

Non-inferiority of combined oxytocin (IM/IV) in preventing severe postpartum blood loss was not shown (17 women in the oxytocin group vs. 7 in the carbetocin group). The number needed to treat when using carbetocin was 28. The risk difference for ∆Hb ≥30 g/L was 0.04 (oxytocin 0.06 vs. 0.03), 95% confidence interval (CI) (0.00-0.08). No significant difference was observed for ∆Hb (median 12 [IQR 7.0-19.0] vs. 11 [5.0-17.0], p = 0.07), estimated blood loss (median 500 [IQR 400-600] vs. 500 [400-575], p = 0.38), or the PPH rate defined as estimated blood loss ≥1000 mL (12[4.5] vs. 5 [2.0], risk difference 0.03, 95% CI (-0.01 to 0.06), p = 0.16). More additional uterotonics were administered in the oxytocin group compared to the carbetocin group (15.2% vs. 5.9%, p = 0.001). Total case costs were non-significantly different in the oxytocin group (US $ 10 146 vs. 9621, mean difference 471.4, CI (-476.5 to 1419.3), p = 0.33).

CONCLUSIONS

Combined (IM/IV) oxytocin is not non-inferior to carbetocin regarding severe postpartum blood loss defined as postpartum Hb decrease ≥30 g/L in elective cesarean sections. We recommend carbetocin for use in clinical practice for elective cesarean sections.

An insight into the pharmacology of cysteine/methionine containing peptide drugs

Since last century, peptides have emerged as potential drugs with >90 FDA approvals for various targets with several in the pipeline. Sulphur, in peptides is present either as thiol (-SH) from Cys or thioether from Met. In this review, all the peptides approved by FDA since 2000 containing sulphur have been included. Among them ∼50 % contains disulphide bridges. This clearly demonstrates the significance of disulphide bonds in peptide drugs. This can be achieved synthetically by using orthogonal protecting groups (PGs) for -SH. These PGs are compatible with Solid Phase Peptide Synthesis (SPPS), which is still the method of choice for peptide synthesis. The orthogonal PGs used for Cys thiol side chain protecting for disulphide bond formation have been included which are currently in use both by academia and industry from small scale to large scale synthesis. In addition, the details of the FDA approved drugs containing Cys and Met (or both) have also been discussed.

Cardiovascular effects of oxytocin and carbetocin at cesarean section. A prospective double-blind randomized study using noninvasive pulse wave analysis

BACKGROUND

Oxytocin is routinely administered after delivery for prophylaxis and treatment of postpartum hemorrhage, but it is associated with considerable cardiovascular side-effects. Carbetocin, a synthetic oxytocin analogue, has a myometrial contraction effect of 60 min when given IV, compared with 16 min for oxytocin.

OBJECTIVE

To investigate whether there are differences in cardiovascular effects between oxytocin and carbetocin up to 1 h after treatment.

METHODS

Sixty-one healthy pregnant women undergoing elective cesarean section in spinal anesthesia were randomized to receive an IV bolus of either five units (8.3 µg) of oxytocin or 100 µg of carbetocin after delivery of the baby. Heart rate (HR), mean arterial blood pressure, ECG ST index, oxygen saturation (SaO₂), and photoplethysmographic digital pulse wave analysis variables were recorded before and at 1, 5, 20, and 60 min after drug administration. Vasopressor use, uterine tonus, total bleeding, and need for additional uterotonics were also assessed. Repeated measurement ANOVA was used for statistical analyses.

RESULTS

The drugs had equal vasodilatory and hypotensive effects. Oxytocin, but not carbetocin, caused a decrease in HR at 1 min and a sustained decrease in cardiac left ventricular ejection time. Aggregate vasopressor use was higher in the carbetocin group. Neither drug caused any change in ST index, SaO₂, or subjective cardiac symptoms. Uterine tonus, need for additional uterotonics, or total bleeding did not differ significantly between the groups.

CONCLUSION

Single doses of oxytocin and carbetocin had similar dilatory effects on vascular tonus, where the difference in aggregate vasopressor use can be attributed to a more persistent hypotensive effect of carbetocin. A transient negative chronotropic and sustained negative inotropic effect occurred after oxytocin. Neither drug showed any alarmingly adverse effects. Differences in drug effects may be attributed to differences in oxytocin and vasopressin receptor signaling pathways.

A study of the pharmacokinetics and pharmacodynamics of oxytocin at elective caesarean delivery

Oxytocin is widely used to prevent atonic postpartum haemorrhage after caesarean delivery. Initial treatment failure rates are high and inadequate dosing may contribute. Excessive doses, however, are associated with serious adverse effects. The pharmacokinetic data from this context are sparse and there is a lack of data in the immediate postpartum minutes after an initiating bolus. The pharmacodynamic data from this context are exclusively from dose-effect studies, with some suggesting that higher doses of oxytocin are required to provide adequate uterine tone in obese compared with non-obese women. We aimed to perform a pharmacokinetic and pharmacodynamic study that would facilitate more precise weight-based oxytocin dosing. We measured arterial oxytocin concentration, uterine tone and haemodynamic parameters in 25 women in the first 40 min after exogenous oxytocin administration at elective caesarean delivery. Serum oxytocin concentrations varied considerably between individuals. We constructed a one-compartment pharmacokinetic model of exogenous oxytocin deposition, after its administration with an initiating bolus and a maintenance infusion, at elective caesarean delivery. Body weight was evaluated as a potential covariate but was not included in the model due to lack of statistically significant reduction in the objective function. We calculated the volume of distribution and clearance (mean [coefficient of variation]) as 156.1 l [18%] and 83 ml.s-1 [32%] but found no within-individual correlation between serum oxytocin concentration and uterine tone or haemodynamic parameters. In conclusion, we observed a large variation in serum oxytocin concentrations between individuals receiving similar doses of oxytocin and were unable to establish weight-based dosing of exogenous oxytocin at caesarean delivery. Our findings suggest that future studies on oxytocin pharmacokinetics would need large sample sizes. In the absence of such data, oxytocin dosing should continue to be guided by uterine tone assessments and adjusted according to a strategy based on the best evidence from dose-effect studies.

Peripherally restricted oxytocin is sufficient to reduce food intake and motivation, while CNS entry is required for locomotor and taste avoidance effects

OBJECTIVES

Oxytocin (OT) has a well-established role in reproductive behaviours; however, it recently emerged as an important regulator of energy homeostasis. In addition to central nervous system (CNS), OT is found in the plasma and OT receptors (OT-R) are found in peripheral tissues relevant to energy balance regulation. Here, we aim to determine whether peripheral OT-R activation is sufficient to alter energy intake and expenditure.

METHODS AND RESULTS

We first show that systemic OT potently reduced food intake and food-motivated behaviour for a high-fat reward in male and female rats. As it is plausible that peripherally, intraperitoneally (IP) injected OT crosses the blood-brain barrier (BBB) to produce some of the metabolic effects within the CNS, we screened, with a novel fluorescently labelled-OT (fAF546-OT, Roxy), for the presence of IP-injected Roxy in CNS tissue relevant to feeding control and compared such with BBB-impermeable fluorescent OT-B₁₂ (fCy5-OT-B_12; BRoxy). While Roxy did penetrate the CNS, BRoxy did not. To evaluate the behavioural and thermoregulatory impact of exclusive activation of peripheral OT-R, we generated a novel BBB-impermeable OT (OT-B₁₂ ), with equipotent binding at OT-R in vitro. In vivo, IP-injected OT and OT-B₁₂ were equipotent at food intake suppression in rats of both sexes, suggesting that peripheral OT acts on peripheral OT-R to reduce feeding behaviour. Importantly, OT induced a potent conditioned taste avoidance, indistinguishable from that induced by LiCl, when applied peripherally. Remarkably, and in contrast to OT, OT-B₁₂ did not induce any conditioned taste avoidance. Limiting the CNS entry of OT also resulted in a dose-dependent reduction of emesis in male shrews. While both OT and OT-B₁₂ proved to have similar effects on body temperature, only OT resulted in home-cage locomotor depression.

CONCLUSIONS

Together our data indicate that limiting systemic OT CNS penetrance preserves the anorexic effects of the peptide and reduces the clinically undesired side effects of OT: emesis, taste avoidance and locomotor depression. Thus, therapeutic targeting of peripheral OT-R may be a viable strategy to achieve appetite suppression with better patient outcomes.

Hemodynamic Effects of Oxytocin and Carbetocin During Elective Cesarean Section in Preeclamptic Patients Under Spinal Anesthesia: A Randomized Double-blind Controlled Study

Background

Oxytocin and carbetocin are uterotonic medications that are used to decrease postpartum hemorrhage (PPH). However, there are not enough clinical data about the hemodynamic side effects of carbetocin.

Objectives

This study aimed to compare carbetocin and oxytocin hemodynamic effects in preeclamptic patients undergoing elective cesarean section under spinal anesthesia.

Methods

In this double-blind, randomized controlled trial, intravenous oxytocin or carbetocin was administered to 80 women (40 per group). The hemodynamic effects, such as blood pressure (BP), heart rate (HR), and oxygen (O₂) saturation, were measured before the operation and after 1, 5, 10, and 15 minutes of the administration of both drugs. Intragroup and intergroup comparisons were conducted during statistical analysis.

Results

Based on the intragroup comparison, there was a significant increase in HR and a reduction in BP from baseline to all intervals after the administration of both interventions. Moreover, based on the intergroup comparison, there was a significantly more increase in HR and a decline in BP and O₂ saturation in the oxytocin group than in the carbetocin group. There were three and seven cases that required another dose of carbetocin and oxytocin, respectively. Moreover, one case developed PPH in the carbetocin group; nevertheless, two cases developed PPH in the oxytocin group.

Conclusions

The minimal effect of carbetocin on patients' hemodynamics suggests extending the use of this drug instead of oxytocin as a uterotonic drug in patients with preeclampsia, hemorrhagic risk factors, and/or hypertension.

[The cesarean procedure: Guidelines for clinical practice from the French College of Obstetricians and Gynecologists]

OBJECTIVE

To identify procedures to reduce maternal morbidity during cesarean.

MATERIAL AND METHODS

The quality of evidence of the literature was assessed following the GRADE® method with questions formulated in the PICO format (Patients, Intervention, Comparison, Outcome) and outcomes defined a priori and classified according to their importance. An extensive bibliographic search was performed on PubMed, Cochrane and EMBASE databases. The quality of the evidence was assessed (high, moderate, low, very low) and a (i) strong or (ii) weak recommendations or (iii) no recommendation were formulated. The recommendations were reviewed in two rounds with external reviewers (Delphi survey) to select the consensus recommendations.

RESULTS

Of the 27 questions, there was agreement between the working group and the external reviewers on 26. The level of evidence of the literature was insufficient to provide a recommendation on 15 questions. Preventing hypothermia is recommended to increase maternal satisfaction and comfort (weak recommendation) and to reduce neonatal hypothermia (strong recommendation). The quality of the evidence of the literature did not allow to recommend the skin disinfectant to be used nor the relevance of a preoperative vaginal disinfection nor the choice between the use or nonuse of an indwelling bladder catheterization (if micturition takes place 1 hour before the cesarean section). The Misgav-Ladach technique or its analogues should be considered rather than the Pfannenstiel technique to reduce maternal morbidity (weak recommendation) bladder flap before uterine incision should not be performed routinely (weak recommendation), but a blunt (weak recommendation) and cephalad-caudad extension of uterine incision (weak recommendation) should be considered to reduce maternal morbidity. Antibiotic prophylaxis is recommended to reduce maternal infectious morbidity (strong recommendation) without recommendation on its type or the timing of administration (before incision or after cord clamping). The administration of carbetocin after cord clamping does not significantly decrease the incidence of blood loss>1000 ml, anemia, or blood transfusion compared with the administration of oxytocin. Thus, it is not recommended to use carbetocin rather than oxytocin in cesarean. It is recommended that systematic manual removal of the placenta not to be performed (weak recommendation). An antiemetic should be administered after cord clamping in women having a planned cesarean under locoregional anaesthesia to reduce intraoperative and postoperative nausea and vomiting (strong recommendation) with no recommendation regarding choice of use one or two antiemetics. The level of evidence of the literature was insufficient to provide any recommendation concerning single or double-layer closure of the uterine incision, or the uterine exteriorization. Closing the peritoneum (visceral or parietal) should not be considered (weak recommendation). The quality of the evidence of the literature was not sufficient to provide recommendation on systematic subcutaneous closure, including in obese or overweight patients, or the use of subcuticular suture in obese or overweight patients. The use of subcuticular suture in comparison with skin closure by staples was not considered as a recommendation due to the absence of a consensus in the external review rounds.

CONCLUSION

In case of cesarean, preventing hypothermia, administering antiemetic and antibiotic prophylaxis after cord clamping are the only strong recommendations. The Misgav-Ladach technique, the way of performing uterine incision (no systematic bladder flap, blunt cephalad-caudad extension), not performing routine manual removal of the placenta nor closure of the peritoneum are weak recommendations and may reduce maternal morbidity.

Intravenous Carbetocin Versus Rectal Misoprostol for the Active Management of the Third Stage of Labor: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Globally, postpartum hemorrhage (PPH) is the top cause of maternal death. Multiple uterotonic medications are available to prevent PPH; however, it is still unclear whether one is the most effective. The current study compared the efficacy and safety of intravenous carbetocin with rectal misoprostol for the active management of the third stage of labor in order to prevent PPH. Eligible studies were found utilizing digital medical sources, including the Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science (WOS), PubMed, Scopus, and Google Scholar, from inception until September 2022. Only randomized controlled trials (RCTs) that matched the inclusion requirements were chosen. We used the Cochrane Risk of Bias scale (version 2) to assess the quality of the included studies. The Review Manager (version 5.4 for Windows) was used to conduct the meta-analysis. The results were summarized as mean difference (MD) or risk ratio (RR) with a 95% confidence interval (CI) in fixed- or random-effects models according to the degree of between-study heterogeneity. Collectively, we screened 621 articles after omitting duplicates and eventually included three RCTs for analysis. Overall, 404 patients were included in these studies; 202 patients were allocated to the intravenous carbetocin group whereas 202 patients were allocated to the rectal misoprostol group. Two RCTs were judged as “low” risk of bias, whereas one RCT was judged as having “some concerns” regarding the quality assessment. Regarding efficacy endpoints, the intravenous carbetocin group had significantly lower blood loss (n=3 RCTs, MD=-117.74 mL, 95% CI [-185.41, -50.07], p<0.001), need for additional uterotonics (n=2 RCTs, RR=0.06, 95% CI [0.01, 0.46], p=0.007), need for uterine massage (n=2 RCTs, RR=0.40, 95% CI [0.20, 0.80], p=0.009), and need for blood transfusion (n=2 RCTs, RR=0.38, 95% CI [0.15, 0.95], p=0.04) compared with the rectal misoprostol group. Regarding safety endpoints, the rates of diarrhea (n=3 RCTs, RR=0.18, 95% CI [0.06, 0.55], p=0.003) and chills (n=2 RCTs, RR=0.31, 95% CI [0.12, 0.83], p=0.02) were significantly lower in the intravenous carbetocin group compared with the rectal misoprostol group. However, there was no significant difference between both groups regarding the rates of headache (n=3 RCTs, RR=1.23, 95% CI [0.06, 1.91], p=0.35) and facial flushing (n=2 RCTs, RR=0.88, 95% CI [0.46, 1.68], p=0.70). In conclusion, it was discovered that intravenous carbetocin was a superior substitute for rectal misoprostol for the active management of the third stage of labor. With far fewer side effects, intravenous carbetocin decreased postpartum blood loss and further uterotonic use. For women who have a high risk of PPH, intravenous carbetocin is advised.

Effectiveness and safety of carboxytocin versus oxytocin in preventing postpartum hemorrhage: A systematic review and meta-analysis

OBJECTIVE

This study compared the effectiveness and safety of carbetocin and oxytocin in preventing postpartum hemorrhage (PPH).

METHODS

A systematic literature search was performed on PubMed, Embase, and the Cochrane Library for relevant studies published up to February 2019. Next, two independent reviewers screened the studies according to the selection criteria as well as the strategies recommended by the Cochrane Collaboration. Data were then extracted and evaluated. All statistical analyses were performed using RevMan 5.1.

RESULTS

A total of 24 studies involving 37 383 patients were included for analysis. For cesarean section patients, carbetocin was superior to oxytocin in reduction of the need for additional uterine contraction (odds ratio [OR] = 0.48, 95% confidence interval [CI] [0.35, 0.65], p < 0.00001), PPH (OR = 0.70, 95% CI [0.51, 0.95], p = 0.02), blood loss (mean [MD] = -64.36, 95% CI [-107.78, -20.93], p = 0.004), and transfusion (OR = 0.59, 95% CI [0.42, 0.82], p = 0.002), and there was no significant difference in severe PPH (OR = 0.84, 95% CI [0.66, 1.090], p = 0.19). For vaginal delivery patients, carbetocin was superior to oxytocin in reduction of the need for additional uterine contractions (OR = 0.48, 95% CI [0.25, 0.93], p = 0.03), PPH (OR = 0.28, 95% CI [0.09, 0.91], p = 0.03), and blood loss (MD = -63.52, 95% CI [-113.43, -13.60], p = 0.01), and there were no significant differences in severe PPH (OR = 0.82, 95% CI [0.40, 1.69], p = 0.59) and transfusion (OR = 0.60, 95% CI [0.22, 1.61], p = 0.31). With regard to safety, for cesarean section patients, carbetocin was superior to oxytocin in reduction of the incidence of headache (OR = 0.72, [0.55, 0.95], p = 0.02), and there were no significant differences in nausea, vomiting, abdominal pain, flushing, tremors, itching, dizziness, and fever. For vaginal delivery patients, there were no significant differences in nausea, vomiting, headache, abdominal pain, flushing, tremors, itching, dizziness, and fever between the two drugs.

CONCLUSION

For patients undergoing cesarean section and vaginal delivery, carbetocin was superior to oxytocin in effectiveness and similar in safety. Therefore, carbetocin is expected to be an alternative uterine contraction agent for preventing PPH.

Preventing postpartum hemorrhage after cesarean delivery: a network meta-analysis of available pharmacologic agents

BACKGROUND

Postpartum hemorrhage causes a quarter of global maternal deaths. The World Health Organization recommends oxytocin as the first line agent to prevent hemorrhage during cesarean delivery. However, some randomized controlled trials suggest that other uterotonics are superior.

OBJECTIVE

We conducted a network meta-analysis comparing the ability of pharmacologic agents to reduce blood loss and minimize the need for additional uterotonics during cesarean delivery.

DATA SOURCES

We searched the Cochrane Central Register of Controlled Trials, Embase, and MEDLINE databases from inception to May 2020.

STUDY ELIGIBILITY CRITERIA

We included randomized controlled trials that compared oxytocin, carbetocin, misoprostol, ergometrine, carboprost, or combinations of these in the prevention of postpartum hemorrhage during cesarean delivery.

METHODS

We performed a systematic review followed by an NMA in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Quality of the evidence was assessed with the Confidence in Network Meta-Analysis approach and Grading of Recommendations, Assessment, Development and Evaluations tool within the summary of findings table. Our primary outcomes were the estimated blood loss and need for additional uterotonics. Secondary outcomes included nausea and postpartum hemorrhage of >1000 mL. We performed sensitivity analyses to explore the influence of surgical context and oxytocin administration strategy.

RESULTS

A total of 46 studies with 7368 participants were included. Of those, 21 trials (6 agents and 3665 participants) formed the "estimated blood loss" network and, considering the treatment effects, certainty in the evidence, and surface under the cumulative ranking curve scores, carbetocin was assessed to probably be superior to oxytocin, but only in reducing the estimated blood loss by a clinically insignificant volume (54.83 mL; 95% confidence interval, 26.48-143.78). Misoprostol, ergometrine, and the combination of oxytocin and ergometrine were assessed to probably be inferior, whereas the combination of oxytocin and misoprostol was assessed to definitely be inferior to oxytocin. A total of 37 trials (8 agents and 6193 participants) formed the "additional uterotonic" network and, again, carbetocin was assessed to probably be superior to oxytocin, requiring additional uterotonics 185 (95% confidence interval, 130-218) fewer times per 1000 cases. Oxytocin plus misoprostol, oxytocin plus ergometrine, and misoprostol were assessed to probably be inferior, whereas carboprost, ergometrine, and the placebo were definitely inferior to oxytocin. For both primary outcomes, oxytocin administration strategies had a higher probability of being the best uterotonic, if initiated as a bolus.

CONCLUSION

Carbetocin is probably the most effective agent in reducing blood loss and the need for additional uterotonics. Oxytocin appears to be more effective when initiated as a bolus.

Side-effects of carbetocin to prevent postpartum hemorrhage: A systematic review and meta-analysis of randomized controlled trials

Postpartum hemorrhage (PPH) increases the risk of maternal death worldwide. Heat-stable carbetocin, a long-acting oxytocin analog, is a newer uterotonic agent. Clinicians do not fully understand its side-effects, particularly the unanticipated side-effects. The aim of this study is to investigate the side-effects of carbetocin to PPH. The Cochrane Library, Web of Science, PubMed, Elsevier ScienceDirect, Embase, and ClinicalTrials.gov were searched from the inception to September 2020. Randomized controlled trials (RCTs) that considered pregnant women who received carbetocin before delivery and provided at least one adverse event were included. Statistical analysis included random or fixed-effect meta-analyses using relative risk. Stratified analyses and sensitivity analyses were also performed. Begger's and Egger's test and funnel plots were used to assess the publication bias. Seventeen RCTs involving 32,702 women were included, and all these studies ranked as medium- to high-quality. Twenty-four side-effects were reported. The use of carbetocin had a lower risk of vomiting in intravenously (0.53, 0.30 to 0.93) and cesarean birth (0.51, 0.32 to 0.81) women, and had a slightly higher risk of diarrhea (8.00, 1.02 to 62.79) compared with oxytocin intervention. No significant difference was found among other side-effects. Evidence from our systematic review and meta-analysis of 17 RCTs suggested that the risk of vomiting decreased with carbetocin use in the prevention of PPH after delivery.

Intramuscular oxytocin versus Syntometrine® versus carbetocin for prevention of primary postpartum haemorrhage after vaginal birth: a randomised double-blinded clinical trial of effectiveness, side effects and quality of life

OBJECTIVE

To compare intramuscular oxytocin, Syntometrine^® and carbetocin for prevention of postpartum haemorrhage after vaginal birth.

DESIGN

Randomised double-blinded clinical trial.

SETTING

Six hospitals in England.

POPULATION

A total of 5929 normotensive women having a singleton vaginal birth.

METHODS

Randomisation when birth was imminent.

MAIN OUTCOME MEASURES

Primary: use of additional uterotonic agents. Secondary: weighed blood loss, transfusion, manual removal of placenta, adverse effects, quality of life.

RESULTS

Participants receiving additional uterotonics: 368 (19.5%) oxytocin, 298 (15.6%) Syntometrine and 364 (19.1%) carbetocin. When pairwise comparisons were made: women receiving carbetocin were significantly more likely to receive additional uterotonics than those receiving Syntometrine (odds ratio [OR] 1.28, 95% CI 1.08-1.51, P = 0.004); the difference between carbetocin and oxytocin was non-significant (P = 0.78); Participants receiving Syntometrine were significantly less likely to receive additional uterotonics than those receiving oxytocin (OR 0.75, 95% CI 0.65-0.91, P = 0.002). Non-inferiority between carbetocin and Syntometrine was not shown. Use of Syntometrine reduced non-drug PPH treatments compared with oxytocin (OR 0.64, 95% CI 0.42-0.97) but not carbetocin (P = 0.64). Rates of PPH and blood transfusion were not different. Syntometrine was associated with an increase in maternal adverse effects and reduced ability of the mother to bond with her baby.

CONCLUSIONS

Non-inferiority of carbetocin to Syntometrine was not shown. Carbetocin is not significantly different to oxytocin for use of additional uterotonics. Use of Syntometrine reduced use of additional uterotonics and need for non-drug PPH treatments compared with oxytocin. Increased maternal adverse effects are a disadvantage of Syntometrine.

TWEETABLE ABSTRACT

IM carbetocin does not reduce additional uterotonic use compared with IM Syntometrine or oxytocin.

A comparative study of three concentrations of intravenous nalbuphine combined with hydromorphone for post-cesarean delivery analgesia

Background:

Nalbuphine has been suggested to be used for post-cesarean section (CS) intravenous analgesia. However, ideal concentration of nalbuphine for such analgesia remains unclear. The present study was conducted to explore an ideal concentration of nalbuphine for post-CS intravenous analgesia by evaluating the analgesic effects and side-effects of three different concentrations of nalbuphine combined with hydromorphone for post-CS intravenous analgesia in healthy parturients.

Methods:

One-hundred-and-fourteen parturients undergoing elective CS were randomly allocated to one of three groups (38 subjects per group) according to an Excel-generated random number sheet to receive hydromorphone 0.05 mg/mL + nalbuphine 0.5 mg/mL (group LN), hydromorphone 0.05 mg/mL + nalbuphine 0.7 mg/mL (group MN), and hydromorphone 0.05 mg/mL + nalbuphine 0.9 mg/mL (group HN) using patient-controlled analgesia (PCA) pump. Visual analog scale (VAS) for pain, PCA bolus demands, cumulative PCA dose, satisfaction score, Ramsay score, and side-effects such as urinary retention were recorded.

Results:

The number of PCA bolus demands and cumulative PCA dose during the first 48 h after CS were significantly higher in group LN (21 ± 16 bolus, 129 ± 25 mL) than those in group MN (15 ± 10 bolus, 120 ± 16 mL) (both P < 0.05) and group HN (13 ± 9 bolus, 117 ± 13 mL) (both P < 0.01), but no difference was found between group HN and group MN (both P > 0.05). VAS scores were significantly lower in group HN than those in group MN and group LN for uterine cramping pain at rest and after breast-feeding within 12 h after CS (all P < 0.01) and VAS scores were significantly higher in group LN than those in group MN and group HN when oxytocin was intravenously infused within 3 days after CS (all P < 0.05), whereas VAS scores were not statistically different among groups for incisional pain (all P > 0.05). Ramsay sedation scale score in group HN was significantly higher than that in group MN at 8 and 12 h after CS (all P < 0.01) and group LN at 4, 8, 12, 24 h after CS (all P < 0.05).

Conclusions:

Hydromorphone 0.05 mg/mL + nalbuphine 0.7 mg/mL for intravenous PCA could effectively improve the incisional pain and uterine cramping pain management and improve comfort in patients after CS.

Trial registration number:

ChiCTR1800015014, http://www.chictr.org.cn/ Chinese Clinical Trial Registry.

Oxytocin in the Male Reproductive Tract; The Therapeutic Potential of Oxytocin-Agonists and-Antagonists

In this review, the role of oxytocin and oxytocin-like agents (acting via the oxytocin receptor and belonging to the oxytocin-family) in the male reproductive tract is considered. Previous research (dating back over 60 years) is revised and connected with recently found aspects of the role oxytocin plays in male reproductive health. The local expression of oxytocin and its receptor in the male reproductive tract of different species is summarized. Colocalization and possible crosstalk to other agents and receptors and their resulting effects are discussed. The role of the newly reported oxytocin focused signaling pathways in the male reproductive tract, other than mediating contractility, is critically examined. The structure and effect of the most promising oxytocin-agonists and -antagonists are reviewed for their potential in treating male disorders with origins in the male reproductive tract such as prostate diseases and ejaculatory disorders.

Uterotonic drugs to prevent postpartum haemorrhage: a network meta-analysis

BACKGROUND

Postpartum haemorrhage (PPH) is the leading cause of maternal mortality worldwide. Prophylactic uterotonic drugs can reduce blood loss and are routinely recommended. There are several uterotonic drugs for preventing PPH, but it is still debatable which drug or combination of drugs is the most effective.

OBJECTIVES

To identify the most effective and cost-effective uterotonic drug(s) to prevent PPH, and generate a ranking according to their effectiveness and side-effect profile.

METHODS

The Cochrane Pregnancy and Childbirth's Trials Register (1 June 2015), ClinicalTrials.gov and the World Health Organization (WHO)'s International Clinical Trials Registry Platform (ICTRP) were searched for unpublished trial reports (30 June 2015). In addition, reference lists of retrieved studies (updated October 2017) were searched for randomised trials evaluating uterotonic drugs for preventing PPH. The study estimated relative effects and rankings for preventing PPH, defined as blood loss of ≥ 500 ml and ≥ 1000 ml. Pairwise meta-analyses and network meta-analysis were performed to determine the relative effects and rankings of all available drugs and combinations thereof [ergometrine, misoprostol (Cytotec^®; Pfizer Inc., New York, NY, USA), misoprostol plus oxytocin (Syntocinon^®; Novartis International AG, Basel, Switzerland), carbetocin (Pabal^®; Ferring Pharmaceuticals, Saint-Prex, Switzerland), ergometrine plus oxytocin (Syntometrine^®; Alliance Pharma plc, Chippenham, UK), oxytocin, and a placebo or no treatment]. Primary outcomes were stratified according to the mode of birth, prior risk of PPH, health-care setting, drug dosage, regimen and route of drug administration. Sensitivity analyses were performed according to study quality and funding source, among others. A model-based economic evaluation compared the relative cost-effectiveness separately for vaginal births and caesareans with or without including side effects.

RESULTS

From 137 randomised trials and 87,466 women, ergometrine plus oxytocin, carbetocin and misoprostol plus oxytocin were found to reduce the risk of PPH blood loss of ≥ 500 ml compared with the standard drug, oxytocin [ergometrine plus oxytocin: risk ratio (RR) 0.69, 95% confidence interval (CI) 0.57 to 0.83; carbetocin: RR 0.72, 95% CI 0.52 to 1.00; misoprostol plus oxytocin: RR 0.73, 95% CI 0.6 to 0.9]. Each of these three strategies had 100% cumulative probability of being ranked first, second or third most effective. Oxytocin was ranked fourth, with an almost 0% cumulative probability of being ranked in the top three. Similar rankings were noted for the reduction of PPH blood loss of ≥ 1000 ml (ergometrine plus oxytocin: RR 0.77, 95% CI 0.61 to 0.95; carbetocin: RR 0.70, 95% CI 0.38 to 1.28; misoprostol plus oxytocin: RR 0.90, 95% CI 0.72 to 1.14), and most secondary outcomes. Ergometrine plus oxytocin and misoprostol plus oxytocin had the poorest ranking for side effects. Carbetocin had a favourable side-effect profile, which was similar to oxytocin. However, the analysis was restricted to high-quality studies, carbetocin lost its ranking and was comparable to oxytocin. The relative cost-effectiveness of the alternative strategies is inconclusive, and the results are affected by both the uncertainty and inconsistency in the data reported on adverse events. For vaginal delivery, when assuming no adverse events, ergometrine plus oxytocin is less costly and more effective than all strategies except carbetocin. The strategy of carbetocin is both more effective and more costly than all other strategies. When taking adverse events into consideration, all prevention strategies, except oxytocin, are more costly and less effective than carbetocin. For delivery by caesarean section, with and without adverse events, the relative cost-effectiveness is different, again because of the uncertainty in the available data.

LIMITATIONS

There was considerable uncertainty in findings within the planned subgroup analyses, and subgroup effects cannot be ruled out.

CONCLUSIONS

Ergometrine plus oxytocin, carbetocin and misoprostol plus oxytocin are more effective uterotonic drug strategies for preventing PPH than the current standard, oxytocin. Ergometrine plus oxytocin and misoprostol plus oxytocin cause significant side effects. Carbetocin has a favourable side-effect profile, which was similar to oxytocin. However, most carbetocin trials are small and of poor quality. There is a need for a large high-quality trial comparing carbetocin with oxytocin; such a trial is currently being conducted by the WHO. The relative cost-effectiveness is inconclusive, and results are affected by uncertainty and inconsistency in adverse events data.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42015020005; Cochrane Pregnancy and Childbirth Group (substudy) reference number 0871; PROSPERO-Cochrane (substudy) reference number CRD42015026568; and sponsor reference number ERN_13-1414 (University of Birmingham, Birmingham, UK).

FUNDING

Funding for this study was provided by the National Institute for Health Research Health Technology Assessment programme in a research award to the University of Birmingham and supported by the UK charity Ammalife (UK-registered charity 1120236). The funders of the study had no role in study design, data collection, data synthesis, interpretation or writing of the report.

Carbetocin compared with oxytocin in non-elective Cesarean delivery: a systematic review, meta-analysis, and trial sequential analysis of randomized-controlled trials

PURPOSE

Carbetocin has been shown to reduce the requirement for additional uterotonics in women exclusively undergoing elective Cesarean delivery (CD). The aim of this review was to determine whether this effect could also be demonstrated in the setting of non-elective CD.

METHODS

Medline, Embase, CINAHL, Web of Science and Cochrane databases were searched for randomized-controlled trials (RCTs) in any language comparing carbetocin to oxytocin. Studies with data on women undergoing non-elective CD, where carbetocin was compared with oxytocin, were included. The primary outcome was the need for additional uterotonics. Secondary outcomes included incidence of blood transfusion, estimated blood loss (mL), incidence of postpartum hemorrhage (PPH; > 1000 mL) and mean hemoglobin drop (g·dL^-1 RESULTS: Five RCTs were included, with a total of 1,214 patients. The need for additional uterotonics was reduced with carbetocin compared with oxytocin (odds ratio, 0.30; 95% CI, 0.11 to 0.86; I², 90.60%). Trial sequential analysis (TSA) confirmed that the information size needed to show a significant reduction in the need for additional uterotonics had been exceeded. No significant differences were shown with respect to any of the secondary outcomes, but there was significant heterogeneity between the studies.

CONCLUSIONS

Carbetocin reduces the need for additional uterotonics in non-elective CD compared with oxytocin. TSA confirmed that this analysis was appropriately powered to detect the pooled estimated effect. Further trials utilizing consistent core outcomes are needed to determine an effect on PPH.

TRIAL REGISTRATION

PROSPERO CRD42019147256, registered 13 September 2019.

Carbetocin versus Oxytocin for the Prevention of Postpartum Hemorrhage in Cesarean Deliveries: A Retrospective Study of Two Consecutive Periods

Objective  The aim of the study is to investigate whether carbetocin prevents postpartum hemorrhage (PPH) more effectively than oxytocin Methods  This historical retrospective single-center cohort study compares women who underwent cesarean deliveries during two periods. During period A, oxytocin was used as a 10-unit bolus immediately after delivery, with 20 units thereafter infused for 24 hours. During period B, carbetocin in a single 100-µg injection replaced this protocol. The main outcome was PPH, defined as a decline in hemoglobin of more than 2 g/dL after the cesarean. The analysis was performed on the overall population and then stratified by the timing of the cesareans (before or during labor). A logistic regression analysis was performed. Results  This study included 1,796 women, 52% of whom had a cesarean before labor; 15% had a PPH. The crude PPH rate was lower in period B than in period A (13 vs. 17%, respectively, odds ratio 0.75, 95% confidence interval [CI]: 0.58-0.98). The difference was no longer significant in the multivariate analysis (adjusted odds ratio: 0.81, 95% CI 0.61-1.06). Results were similar when stratified by the timing of the cesareans (before or during labor). Conclusion  Carbetocin is not superior to oxytocin in preventing PPH. However, it does provide the advantage of requiring a single injection.

Carbetocin versus oxytocin for prevention of postpartum hemorrhage in hypertensive women undergoing elective cesarean section

OBJECTIVE

Assess the efficacy and safety of carbetocin, versus oxytocin in the prevention of postpartum hemorrhage in hypertensive women.

STUDY DESIGN

A randomized clinical trial.

SETTING

Obstetrics and Gynecology Department of Suez Canal University Hospital.

PATIENTS

One hundred and sixty hypertensive pregnant women who underwent CS.

INTERVENTIONS

Patients were randomized to receive either 10 IU oxytocin or 100 μg carbetocin. Primary outcomes included estimated blood loss, blood transfusion, hemoglobin (HB), and hematocrit changes pre- and post-delivery and the use of additional uterotonics.

RESULTS

The postoperative HB was not different from preoperative HB in the carbetocin group (11.8 ± 1.2 vs. 11.2 ± 1.2 g/dL) while it decreased significantly in the oxytocin group (12.1 ± 3.8 vs. 10.4 ± 1.1 g/dL, p < 0.001). Blood loss was significantly more among the oxytocin group (679.5 ± 200.25 vs. 424.75 ± 182.59 ml) in the carbetocin group (p < 0.001). Nausea, vomiting, and sweating were reported more significantly in oxytocin group patients.

CONCLUSION

Carbetocin was more effective than oxytocin in reducing intraoperative and postoperative blood loss.

Postpartum haemorrhage (PPH) rates in randomized trials of PPH prophylactic interventions and the effect of underlying participant PPH risk: a meta-analysis

Background

Postpartum haemorrhage (PPH) remains a leading cause of maternal mortality. Many trials assessing interventions to prevent PPH base their data on low risk women. It is important to consider the impact data collection methods may have on these results. This review aims to assess trials of PPH prophylaxis by grading trials according to the degree of risk status of the population enrolled in these trials and identify differences in the PPH rates of low risk and high risk populations.

Methods

Systematic review and meta-analysis using a random-effects model. Trials were identified through CENTRAL. Trials were assessed for eligibility then graded according to antenatal risk factors and method of birth into five grades. The main outcomes were overall trial rate of minor PPH (blood loss ≥500 ml) and major PPH (> 1000 ml) and method of determining blood loss (estimated/measured).

Results

There was no relationship between minor or major PPH rate and risk grade (Kruskal-Wallis: minor - T = 0.92, p = 0.82; major - T = 0.91, p = 0.92). There was no difference in minor or major PPH rates when comparing estimation or measurement methods (Mann-Whitney: minor - U = 67, p = 0.75; major - U = 35, p = 0.72). There was however a correlation between % operative births and minor PPH rate, but not major PPH (Spearman r = 0.32 v. Spearman r = 0.098).

Conclusions

Using data from trials using low risk women to generalise best practice guidelines might not be appropriate for all births, particularly complex births. Although complex births contribute disproportionately to PPH rates, this review showed they are often underrepresented in trials. Despite this, there was no difference in reported PPH rates between studies conducted in high and low risk groups. Method of birth was shown to be an important risk factor for minor PPH and may be a better predictor of PPH than antenatal risk factors. Women with operative births are often excluded from trials meaning a lack of data supporting interventions in these women. More focus on complex births is needed to ensure the evidence base is relevant to the target population.

Oxytocin: Potential to mitigate cardiovascular risk

Cardiovascular disease (CVD) remains the leading cause of death worldwide, despite multiple treatment options. In addition to elevated lipid levels, oxidative stress and inflammation are key factors driving atherogenesis and CVD. New strategies are required to mitigate risk and most urgently for statin-intolerant patients. The neuropeptide hormone oxytocin, synthesized in the brain hypothalamus, is worthy of consideration as a CVD ancillary treatment because it moderates factors directly linked to atherosclerotic CVD such as inflammation, weight gain, food intake and insulin resistance. Though initially studied for its contribution to parturition and lactation, oxytocin participates in social attachment and bonding, associative learning, memory and stress responses. Oxytocin has shown promise in animal models of atherosclerosis and in some human studies as well. A number of properties of oxytocin make it a candidate CVD treatment. Oxytocin not only lowers fat mass and cytokine levels, but also improves glucose tolerance, lowers blood pressure and relieves anxiety. Further, it has an important role in communication in the gut-brain axis that makes it a promising treatment for obesity and type 2 diabetes. Oxytocin acts through its receptor which is a class I G-protein-coupled receptor present in cells of the vascular system including the heart and arteries. While oxytocin is not used for heart disease at present, residual CVD risk remains in a substantial portion of patients despite multidrug regimens, leaving open the possibility of using the endogenous nonapeptide as an adjunct therapy. This review discusses the possible role for oxytocin in human CVD prevention and treatment.

What does basic science tell us about the use of uterotonics?

Pharmacotherapy with uterotonics remains the mainstay of the management for post-partum haemorrhage. Clinical studies evaluating the efficacy of these drugs are fraught with confounders, which may influence uterine contractility and blood loss. For this reason, a range of techniques have been developed to study myometrial function in vitro, allowing for the comparison of various drugs in a controlled-simulated physiological environment. In this review, we focus on the main classes of uterotonic drugs and outline their molecular and physiological basis of action. We explore the evidence related to appropriate drug dosing and relative efficacy, and compare the evidence gleaned from clinical and in vitro studies. We discuss the mechanism of oxytocin desensitisation and how basic science has helped us understand this phenomenon. We also discuss the in vitro research findings for each of the main classes of uterotonic drugs that have contributed to an improved understanding of the management of post-partum haemorrhage and, ultimately, better care for mothers.

A comparison of the efficacy of carbetocin and oxytocin on hemorrhage-related changes in women with cesarean deliveries for different indications

OBJECTIVE

To compare the efficacy of carbetocin and oxytocin on hemorrhage-related changes in women with cesarean deliveries (CS) for different indications.

MATERIALS AND METHODS

A retrospective cohort study was conducted on 1568 women with CS before labor onset (elective CS, n = 1153) or during labor (intrapartum CS, n = 415) after 24 weeks' gestation. We compared the fall in hemoglobin (Hb) and hematocrit (Hct) levels after CS, estimated blood loss, the need for additional uterotonic agents, blood transfusion, and the rate of postpartum hemorrhage between women with carbetocin and women with oxytocin treatment, stratified by indications for CS.

RESULTS

For women with elective CS, decreased Hb and Hct falls were noted with carbetocin treatment compared to oxytocin treatment in women with indications for prior CS, fetal malpresentation, and multiple gestation. The need for additional uterotonics was less in CS for prior CS, fetal malpresentation, and cephalopelvic disproportion and fewer transfusions in CS for multiple gestation in women with carbetocin compared to women with oxytocin treatment. For women with intrapartum CS, carbetocin was associated with decreased use of additional uterotonic agents and transfusion in CS for dysfunctional labor.

CONCLUSION

Carbetocin and oxytocin had differential effects on hemorrhage-related changes in women with CS for different indications.

Design of Oxytocin Analogs

The neurohypophyseal hormone oxytocin (OT) and related modulators of the oxytocin receptor (OTR) have been the subject of intensive research for nearly seven decades. Despite having rather poor drug-like properties, OT is used as a treatment for labor induction, postpartum hemorrhage, and lactation support. The potential use of OT in the treatment of central nervous system (CNS)-related diseases has recently renewed interest in the pharmacology of OT. Oxytocin is one of the most extensively studied cyclic peptides and since the elucidation of its structure in 1953 thousands of peptidic OT analogs with antagonistic and agonistic properties have been synthesized and biologically evaluated. Among them are atosiban, a mixed oxytocin receptor (OTR)/vasopressin 1a receptor (V_1aR) antagonist used as a tocolytic agent approved (in certain countries), and carbetocin, a longer acting OTR agonist on the market for the treatment of postpartum hemorrhage. Many other OT analogs with improved pharmacological properties (e.g., barusiban, Antag III) have been identified. These peptides have been tested in clinical trials and/or used as pharmacological tools. In this chapter, the modifications of the OT molecule that led to the discovery of these compounds are reviewed.

Uterotonic agents for preventing postpartum haemorrhage: a network meta-analysis

BACKGROUND

Postpartum haemorrhage (PPH) is the leading cause of maternal mortality worldwide. Prophylactic uterotonic agents can prevent PPH, and are routinely recommended. The current World Health Organization (WHO) recommendation for preventing PPH is 10 IU (international units) of intramuscular or intravenous oxytocin. There are several uterotonic agents for preventing PPH but there is still uncertainty about which agent is most effective with the least side effects. This is an update of a Cochrane Review which was first published in April 2018 and was updated to incorporate results from a recent large WHO trial.

OBJECTIVES

To identify the most effective uterotonic agent(s) to prevent PPH with the least side effects, and generate a ranking according to their effectiveness and side-effect profile.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (24 May 2018), and reference lists of retrieved studies.

SELECTION CRITERIA

All randomised controlled trials or cluster-randomised trials comparing the effectiveness and side effects of uterotonic agents with other uterotonic agents, placebo or no treatment for preventing PPH were eligible for inclusion. Quasi-randomised trials were excluded. Randomised trials published only as abstracts were eligible if sufficient information could be retrieved.

DATA COLLECTION AND ANALYSIS

At least three review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. We estimated the relative effects and rankings for preventing PPH ≥ 500 mL and PPH ≥ 1000 mL as primary outcomes. Secondary outcomes included blood loss and related outcomes, morbidity outcomes, maternal well-being and satisfaction and side effects. Primary outcomes were also reported for pre-specified subgroups, stratifying by mode of birth, prior risk of PPH, healthcare setting, dosage, regimen and route of administration. We performed pairwise meta-analyses and network meta-analysis to determine the relative effects and rankings of all available agents.

MAIN RESULTS

The network meta-analysis included 196 trials (135,559 women) involving seven uterotonic agents and placebo or no treatment, conducted across 53 countries (including high-, middle- and low-income countries). Most trials were performed in a hospital setting (187/196, 95.4%) with women undergoing a vaginal birth (71.5%, 140/196).Relative effects from the network meta-analysis suggested that all agents were effective for preventing PPH ≥ 500 mL when compared with placebo or no treatment. The three highest ranked uterotonic agents for prevention of PPH ≥ 500 mL were ergometrine plus oxytocin combination, misoprostol plus oxytocin combination and carbetocin. There is evidence that ergometrine plus oxytocin (RR 0.70, 95% CI 0.59 to 0.84, moderate certainty), carbetocin (RR 0.72, 95% CI 0.56 to 0.93, moderate certainty) and misoprostol plus oxytocin (RR 0.70, 95% CI 0.58 to 0.86, low certainty) may reduce PPH ≥ 500 mL compared with oxytocin. Low-certainty evidence suggests that misoprostol, injectable prostaglandins, and ergometrine may make little or no difference to this outcome compared with oxytocin.All agents except ergometrine and injectable prostaglandins were effective for preventing PPH ≥ 1000 mL when compared with placebo or no treatment. High-certainty evidence suggests that ergometrine plus oxytocin (RR 0.83, 95% CI 0.66 to 1.03) and misoprostol plus oxytocin (RR 0.88, 95% CI 0.70 to 1.11) make little or no difference in the outcome of PPH ≥ 1000 mL compared with oxytocin. Low-certainty evidence suggests that ergometrine may make little or no difference to this outcome compared with oxytocin meanwhile the evidence on carbetocin was of very low certainty. High-certainty evidence suggests that misoprostol is less effective in preventing PPH ≥ 1000 mL when compared with oxytocin (RR 1.19, 95% CI 1.01 to 1.42). Despite the comparable relative treatment effects between all uterotonics (except misoprostol) and oxytocin, ergometrine plus oxytocin, misoprostol plus oxytocin combinations and carbetocin were the highest ranked agents for PPH ≥ 1000 mL.Misoprostol plus oxytocin reduces the use of additional uterotonics (RR 0.56, 95% CI 0.42 to 0.73, high certainty) and probably also reduces the risk of blood transfusion (RR 0.51, 95% CI 0.37 to 0.70, moderate certainty) when compared with oxytocin. Carbetocin, injectable prostaglandins and ergometrine plus oxytocin may also reduce the use of additional uterotonics but the certainty of the evidence is low. No meaningful differences could be detected between all agents for maternal deaths or severe morbidity as these outcomes were rare in the included randomised trials where they were reported.The two combination regimens were associated with important side effects. When compared with oxytocin, misoprostol plus oxytocin combination increases the likelihood of vomiting (RR 2.11, 95% CI 1.39 to 3.18, high certainty) and fever (RR 3.14, 95% CI 2.20 to 4.49, moderate certainty). Ergometrine plus oxytocin increases the likelihood of vomiting (RR 2.93, 95% CI 2.08 to 4.13, moderate certainty) and may make little or no difference to the risk of hypertension, however absolute effects varied considerably and the certainty of the evidence was low for this outcome.Subgroup analyses did not reveal important subgroup differences by mode of birth (caesarean versus vaginal birth), setting (hospital versus community), risk of PPH (high versus low risk for PPH), dose of misoprostol (≥ 600 mcg versus < 600 mcg) and regimen of oxytocin (bolus versus bolus plus infusion versus infusion only).

AUTHORS' CONCLUSIONS

All agents were generally effective for preventing PPH when compared with placebo or no treatment. Ergometrine plus oxytocin combination, carbetocin, and misoprostol plus oxytocin combination may have some additional desirable effects compared with the current standard oxytocin. The two combination regimens, however, are associated with significant side effects. Carbetocin may be more effective than oxytocin for some outcomes without an increase in side effects.

Efficacy and safety of carbetocin given as an intravenous bolus compared with short infusion for Caesarean section - double-blind, double-dummy, randomized controlled non-inferiority trial

Background

Carbetocin is a synthetic oxytocin-analogue, which should be administered as bolus according to manufacturer's recommendations. A higher speed of oxytocin administration leads to increased cardiovascular side-effects. It is unclear whether carbetocin administration as short infusion has the same efficacy on uterine tone compared with bolus administration and whether haemodynamic parameters differ.

Methods

In this randomized, double-blind, non-inferiority trial, women undergoing planned or unplanned Caesarean section (CS) under regional anaesthesia received a bolus and a short infusion, only one of which contained carbetocin 100 mcg (double dummy). Obstetricians quantified uterine tone two, three, five and 10 min after cord-clamping by manual palpation using a linear analogue scale from 0 to 100. We evaluated whether the lower limit of the 95% CI of the difference in maximum uterine tone within the first five min after cord-clamping did not include the pre-specified non-inferiority limit of -10.

Results

Between December 2014 and November 2015, 69 patients were randomized to receive carbetocin as bolus and 71 to receive it as short infusion. Maximal uterine tone was 89 in the bolus and 88 in the short infusion group (mean difference -1.3, 95% CI -5.7 to 3.1). Bp, calculated blood loss, use of additional uterotonics, and side-effects were comparable.

Conclusions

Administration of carbetocin as short infusion does not compromise uterine tone and has similar cardiovascular side-effects as a slow i.v. bolus. In accordance with current recommendations for oxytocin, carbetocin can safely be administered as short -infusion during planned or unplanned CS.

Clinical trial registration

ClinicalTrials.gov NCT02221531 and www.kofam.ch SNCTP000001197.

The effect of carbetocin compared to misoprostol in management of the third stage of labor and prevention of postpartum hemorrhage: a systematic review

BACKGROUND

Postpartum hemorrhage (PPH) and the amount of blood loss are directly related to management of the third stage of labor. No previous report has compared the effects of carbetocin to those of misoprostol. The aim of this systematic review was to compare the effects of carbetocin to those of misoprostol for management of the third stage of labor and for the prevention of PPH.

METHODS

We searched the Cochrane Library (Central), Web of Science, Scopus, Science Direct, Ovid, clinicaltrial.gov , and PubMed databases on December 28, 2017. Data extraction and risk of bias assessment were performed by 2 of the authors independently. Individual and pooled incidences were calculated for the included studies, with 95% confidence intervals (CIs). We used a fixed model for forest plots without heterogeneity and a random effect model for those with heterogeneity.

RESULTS

Our search identified 117 studies; however, 29 studies were duplicate. Of the 88 non-duplicate studies, 5 met the inclusion criteria. Of these five studies, two are currently underway. Hence, three studies were finally included in our meta-analysis. The pooled estimate of the impact of carbetocin on PPH (500-1000 ml) was (OR 0.27, 95% CI 0.14-0.50). Carbetocin significantly reduced the need for additional uterotonics (RR 0.28, 95% CI 0.15 to 0.49). Reduction in the hemoglobin level and blood loss during the third stage of labor was significantly lower in women who received carbetocin than in those who received misoprostol. The length of the third stage of labor was significantly lower in women who received carbetocin than in those who received misoprostol. The incidence of side effects, such as heat sensation, metallic taste, fever, and shivering, were significantly lower in women who received carbetocin than in those who received misoprostol.

CONCLUSION

Although this review showed that carbetocin is effective for decreasing PPH, blood loss, the length of the third stage of labor, and the need for additional uterotonics, this conclusion should be considered with caution. Because assessment of PPH is a subjective issue and it is uncertain whether outcomes were assessed blindly in respect to treatment. We recommend future research to verify our findings. Also clinicians may like to consider use of carbetocin for women with low risk for PPH.

Efficacy of carbetocin for preventing postpartum bleeding after cesarean section in twin pregnancy

Objective: This is a prospective observational study whose goal was to compare the effectiveness of carbetocin and oxytocin for prevention of postpartum hemorrhage (PPH) when they are administered in twin pregnancies undergoing a cesarean section.Design: We enrolled 166 twin pregnancies at term undergoing elective or emergency cesarean section. We compared the effect of a single 100 µg dose of carbetocin with the use of oxytocin as a protocol (20 IU in Ringer lactate 500 ml in 10-15 min). The main variables studied were intraoperative bleeding, surgical time, hemoglobin fall, hematocrit drop, additional uterotonic use (Methylergometrine and/or misoprostol), need for blood transfusion, and/or IV iron therapy.Results: In the oxytocin group there was a greater fall in the hemoglobin level (1.7 versus 1.2, p = .02). Along the same line, the control group presented a significantly greater need for blood transfusion (9.3 versus 1.3%, =0.03), as well as treatment for anemia as a composite variable (intravenous (IV) iron therapy and/or blood transfusion) 16.3 versus 3.85% for each group [OR 0.2 (0.05-0.72)]. In addition, the use of carbetocin was associated with a reduction in the need to administer additional treatments (uterotonic and/or treatment for anemia) during the postpartum period compared with the use of oxytocin O.R 0.32 (0.12-0.88).Conclusions: In our population of twin pregnancies delivered by cesarean section, carbetocin appears more effective than oxytocin in preventing PPH.

Uterotonic agents for preventing postpartum haemorrhage: a network meta-analysis

BACKGROUND

Postpartum haemorrhage (PPH) is the leading cause of maternal mortality worldwide. Prophylactic uterotonic drugs can prevent PPH, and are routinely recommended. There are several uterotonic drugs for preventing PPH but it is still debatable which drug is best.

OBJECTIVES

To identify the most effective uterotonic drug(s) to prevent PPH, and generate a ranking according to their effectiveness and side-effect profile.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register (1 June 2015), ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) for unpublished trial reports (30 June 2015) and reference lists of retrieved studies.

SELECTION CRITERIA

All randomised controlled comparisons or cluster trials of effectiveness or side-effects of uterotonic drugs for preventing PPH.Quasi-randomised trials and cross-over trials are not eligible for inclusion in this review.

DATA COLLECTION AND ANALYSIS

At least three review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. We estimated the relative effects and rankings for preventing PPH ≥ 500 mL and PPH ≥ 1000 mL as primary outcomes. We performed pairwise meta-analyses and network meta-analysis to determine the relative effects and rankings of all available drugs. We stratified our primary outcomes according to mode of birth, prior risk of PPH, healthcare setting, dosage, regimen and route of drug administration, to detect subgroup effects.The absolute risks in the oxytocin are based on meta-analyses of proportions from the studies included in this review and the risks in the intervention groups were based on the assumed risk in the oxytocin group and the relative effects of the interventions.

MAIN RESULTS

This network meta-analysis included 140 randomised trials with data from 88,947 women. There are two large ongoing studies. The trials were mostly carried out in hospital settings and recruited women who were predominantly more than 37 weeks of gestation having a vaginal birth. The majority of trials were assessed to have uncertain risk of bias due to poor reporting of study design. This primarily impacted on our confidence in comparisons involving carbetocin trials more than other uterotonics.The three most effective drugs for prevention of PPH ≥ 500 mL were ergometrine plus oxytocin combination, carbetocin, and misoprostol plus oxytocin combination. These three options were more effective at preventing PPH ≥ 500 mL compared with oxytocin, the drug currently recommended by the WHO (ergometrine plus oxytocin risk ratio (RR) 0.69 (95% confidence interval (CI) 0.57 to 0.83), moderate-quality evidence; carbetocin RR 0.72 (95% CI 0.52 to 1.00), very low-quality evidence; misoprostol plus oxytocin RR 0.73 (95% CI 0.60 to 0.90), moderate-quality evidence). Based on these results, about 10.5% women given oxytocin would experience a PPH of ≥ 500 mL compared with 7.2% given ergometrine plus oxytocin combination, 7.6% given carbetocin, and 7.7% given misoprostol plus oxytocin. Oxytocin was ranked fourth with close to 0% cumulative probability of being ranked in the top three for PPH ≥ 500 mL.The outcomes and rankings for the outcome of PPH ≥ 1000 mL were similar to those of PPH ≥ 500 mL. with the evidence for ergometrine plus oxytocin combination being more effective than oxytocin (RR 0.77 (95% CI 0.61 to 0.95), high-quality evidence) being more certain than that for carbetocin (RR 0.70 (95% CI 0.38 to 1.28), low-quality evidence), or misoprostol plus oxytocin combination (RR 0.90 (95% CI 0.72 to 1.14), moderate-quality evidence)There were no meaningful differences between all drugs for maternal deaths or severe morbidity as these outcomes were so rare in the included randomised trials.Two combination regimens had the poorest rankings for side-effects. Specifically, the ergometrine plus oxytocin combination had the higher risk for vomiting (RR 3.10 (95% CI 2.11 to 4.56), high-quality evidence; 1.9% versus 0.6%) and hypertension [RR 1.77 (95% CI 0.55 to 5.66), low-quality evidence; 1.2% versus 0.7%), while the misoprostol plus oxytocin combination had the higher risk for fever (RR 3.18 (95% CI 2.22 to 4.55), moderate-quality evidence; 11.4% versus 3.6%) when compared with oxytocin. Carbetocin had similar risk for side-effects compared with oxytocin although the quality evidence was very low for vomiting and for fever, and was low for hypertension.

AUTHORS' CONCLUSIONS

Ergometrine plus oxytocin combination, carbetocin, and misoprostol plus oxytocin combination were more effective for preventing PPH ≥ 500 mL than the current standard oxytocin. Ergometrine plus oxytocin combination was more effective for preventing PPH ≥ 1000 mL than oxytocin. Misoprostol plus oxytocin combination evidence is less consistent and may relate to different routes and doses of misoprostol used in the studies. Carbetocin had the most favourable side-effect profile amongst the top three options; however, most carbetocin trials were small and at high risk of bias.Amongst the 11 ongoing studies listed in this review there are two key studies that will inform a future update of this review. The first is a WHO-led multi-centre study comparing the effectiveness of a room temperature stable carbetocin versus oxytocin (administered intramuscularly) for preventing PPH in women having a vaginal birth. The trial includes around 30,000 women from 10 countries. The other is a UK-based trial recruiting more than 6000 women to a three-arm trial comparing carbetocin, oxytocin and ergometrine plus oxytocin combination. Both trials are expected to report in 2018.Consultation with our consumer group demonstrated the need for more research into PPH outcomes identified as priorities for women and their families, such as women's views regarding the drugs used, clinical signs of excessive blood loss, neonatal unit admissions and breastfeeding at discharge. To date, trials have rarely investigated these outcomes. Consumers also considered the side-effects of uterotonic drugs to be important but these were often not reported. A forthcoming set of core outcomes relating to PPH will identify outcomes to prioritise in trial reporting and will inform futures updates of this review. We urge all trialists to consider measuring these outcomes for each drug in all future randomised trials. Lastly, future evidence synthesis research could compare the effects of different dosages and routes of administration for the most effective drugs.

Cost effectiveness analysis of carbetocin during cesarean section in a high volume maternity unit

AIM

To evaluate the cost effectiveness of carbetocin compared to oxytocin when used as prophylaxis against post-partum hemorrhage (PPH) during cesarean deliveries.

METHODS

A systematic review of the literature was performed to identify randomized controlled trials that compared the use of carbetocin to oxytocin in the context of cesarean deliveries. Cost effectiveness analysis was then performed using secondary data from the perspective of a maternity unit within the Malaysian Ministry of Health, over a 24 h time period.

RESULTS

Seven randomized controlled trials with over 2000 patients comparing carbetocin with oxytocin during cesarean section were identified. The use of carbetocin in our center, which has an average of 3000 cesarean deliveries annually, would have prevented 108 episodes of PPH, 104 episodes of transfusion and reduced the need for additional uterotonics in 455 patients. The incremental cost effectiveness ratio of carbetocin for averting an episode of PPH was US$278.70.

CONCLUSION

Reduction in retreatment, staffing requirements, transfusion and potential medication errors mitigates the higher index cost of carbetocin. From a pharmacoeconomic perspective, in the context of cesarean section, carbetocin was cost effective as prophylaxis against PPH. Ultimately, the relative value placed on the outcomes above and the individual unit's resources would influence the choice of uterotonic.

Pharmacoeconomic study comparing carbetocin with oxytocin for the prevention of hemorrhage following cesarean delivery in Lima, Peru

Postpartum hemorrhage is one of the main causes of maternal death. Oxytocin has traditionally been used to prevent postpartum hemorrhage.

AIM

To compare oxytocin with carbetocin, a long-acting analog of oxytocin, for prevention of uterine hemorrhage after cesarean delivery.

MATERIALS & METHODS

Clinical data were retrieved from the 2012 Cochrane meta-analysis "Carbetocin for preventing postpartum hemorrhage". A decision tree was constructed. The direct costs were those of medications from the Peruvian official price list (DIGEMID). Costs associated with additional oxytocic drugs, blood transfusions, postpartum hemorrhage kits and hysterectomy were obtained from Hospital Nacional Edgardo Rebagliati Martins. The perspective of the study was that of the payer. The time horizon for calculating quality-adjusted life years (QALYs) was 1 year (2015).

RESULTS

Patients who received carbetocin required fewer additional uterotonic agents, had fewer hemorrhages and received fewer blood transfusions. Therefore, the costs associated with these interventions were lower. The incremental cost-effectiveness ratio was S/. 49,918 per QALY gained, which is lower than the threshold we estimated for Peru.

CONCLUSION

Carbetocin is more cost-effective than oxytocin for prevention of uterine hemorrhage after cesarean delivery.

Lack of controlled studies investigating the risk of postpartum haemorrhage in cesarean delivery after prior use of oxytocin: a scoping review

BACKGROUND

Postpartum haemorrhage (PPH) is a major cause of maternal mortality and morbidity worldwide. Experimental and clinical studies indicate that prolonged oxytocin exposure in the first or second stage of labour may be associated with impaired uterine contractility and an increased risk of atonic PPH. Therefore, particularly labouring women requiring cesarean delivery constitute a subset of patients that may exhibit an unpredictable response to oxytocin. We mapped the evidence for comparative studies investigating the hypothesis whether the risk for PPH is increased in women requiring cesarean section after induction or augmentation of labour.

METHODS

We performed a systematic literature search for clinical trials in Medline, Embase, Web of Science, and the Cochrane Library (May 2016). Additionally we searched for ongoing or unpublished trials in clinicaltrials.gov and the WHO registry platform. We identified a total of 36 controlled trials investigating the exogenous use of oxytocin in cesarean section. Data were extracted for study key characteristics and the current literature literature was described narratively.

RESULTS

Our evidence map shows that the majority of studies investigating the outcome PPH focused on prophylactic oxytocin use compared to other uterotonic agents in the third stage of labour. Only 2 dose-response studies investigated the required oxytocin dose to prevent uterine atony after cesarean delivery for labour arrest. These studies support the hypotheses that labouring women exposed to exogenous oxytocin require a higher oxytocin dose after delivery than non-labouring women to prevent uterine atony after cesarean section. However, the study findings are flawed by limitations of the study design as well as the outcome selection. No clinical trial was identified that directly compared exogenous oxytocin versus no oxytocin application before intrapartum cesarean delivery.

CONCLUSION

Despite some evidence from dose-response studies that the use of oxytocin may increase the risk for PPH in intrapartum cesarean delivery, current research has not investigated the prepartal application of oxytocin in well controlled clinical trials. It was striking that most studies on exogenous oxytocin are focused on PPH prophylaxis in the third stage of labour without differing between the indications of cesarean section and hence the prepartal oxytocin status.

Analysis of the cost-effectiveness of carbetocin for the prevention of hemorrhage following cesarean delivery in Ecuador

AIM

To compare the cost of carbetocin with that of oxytocin for the prevention and management of hemorrhage following cesarean delivery in Ecuador.

MATERIALS & METHODS

We developed a decision tree based cost-effectiveness model to compare carbetocin with oxytocin in the prevention of hemorrhage following cesarean delivery in Ecuador. Our model was run from a third party payer perspective and was validated by local experts in the field. The efficacy of the interventions was determined based on a systematic review of the literature. Direct costs were calculated based on current National Health Service price lists and retail price. Since the period covered by the analysis was 1 year, costs and health effects were not discounted.

RESULTS

The difference in costs between the interventions was US$16.26, with a difference in effectiveness of 0.0067 disability adjusted life years averted. The incremental cost-effectiveness ratio for carbetocin compared with oxytocin for prevention of hemorrhage following cesarean delivery was US$2432.89 per disability adjusted life year averted.

CONCLUSION

Carbetocin is as efficacious and safe as oxytocin for primary prevention of hemorrhage in cesarean delivery in Ecuador. It is highly cost effective for reducing the need for additional uterotonic drugs in both emergency and elective cesarean delivery.

Efficacy of oxytocin versus carbetocin in prevention of postpartum hemorrhage after cesarean section under general anesthesia: a prospective randomized clinical trial

OBJECTIVE

To compare the use of carbetocin and oxytocin in the prevention of postpartum hemorrhage after cesarean section.

METHODS

The present study was a prospective double-blind randomized controlled clinical trial performed in two university-based hospitals in Tehran, Iran. Two hundred and twenty women with the gestational age of more than 37 weeks, who needed cesarean operation, participated in the study. Patients were assigned to receive either a single 100 μg IV dose of carbetocin or a standard 30-international unit IV infusion of oxytocin during 2 h after delivery of placenta. The primary outcome measures were postpartum hemorrhage requiring additional uterotonic drugs, bleeding volume, and the hemoglobin drops.

RESULTS

There were meaningful differences in carbetocin versus oxytocin group regarding the hemoglobin drops (1.01 versus 2.05, p = .01), bleeding volume (430.68 CC versus 552.6 CC, p < .001), uterine massages frequency (3.7 versus 4.26, p < .001), and uterine height at 2, 4, and 24 h (p < .001). Oxytocin side effects were significantly higher in comparison with the carbetocin except pruritus which was observed in 27% of patients in the carbetocin versus no cases in the oxytocin group.

CONCLUSIONS

It may be concluded that carbetocin is a good alternative modality to conventional uterotonic agents such as oxytocin for the prevention of postpartum hemorrhage after cesarean sections. Registration ID in IRCT: NCT02079558.

Carbetocin versus syntometrine for prevention of postpartum hemorrhage after cesarean section

OBJECTIVE

To compare effectiveness and tolerability of carbetocin versus syntometrine in prevention of postpartum hemorrhage (PPH) after cesarean section (CS).

METHODS

A double-blind randomized study conducted on 300 pregnant subjected randomly either to single 100 μg IV dose of carbetocin (150 women) or combination of 5 IU oxytocin and 0.2 mg ergometrine (150 women) after fetal extraction and before placental removal. Primary outcome parameter was the occurrence of PPH. Other parameters were hemoglobin and hematocrit changes, the need of additional oxytocic, hemodynamic changes and occurrence of side effects.

RESULTS

There was no significant difference between the two study groups regarding hemoglobin and hematocrit at start of CS and after 2 days of surgery and mean blood loss during the operation (p > 0.05). There was a highly significant difference between the two study groups regarding incidence of primary PPH (2.7% versus10%) and the need of additional oxytocic (3.3% versus17.3%). Women in oxytocin group showed a statistically significant lower systolic and diastolic blood pressure at 1, 5 and 30 min than women in carbetocin group. Women in carbetocin group experienced more metallic taste, flushing, headache, dizziness, dyspnea and itching, while women in oxytocin methergine group experienced more palpitations.

CONCLUSIONS

Carbetocin is a reasonable effective alternative to syntometrine in prevention of PPH after cesarean delivery.

A prospective cohort study evaluating the cost-effectiveness of carbetocin for prevention of postpartum haemorrhage in caesarean sections

Postpartum haemorrhage (PPH) is the leading cause of maternal mortality worldwide. Prophylaxis with oxytocic medication is recommended by the WHO to prevent its occurrence. Carbetocin is a newer oxytocic, with potential to lower PPH rates, reduce the total use of oxytocic drugs and lead to financial savings. Meta-analyses have confirmed a reduction in the use of additional oxytocic medication with the use of carbetocin compared to oxytocin. However, there are few studies evaluating the costs of carbetocin prophylaxis. We carried out a prospective cohort study evaluating the financial impact of carbetocin, following its introduction at our centre for caesarean section. We collected data for 400 patients in total, making this, to our knowledge, the largest study conducted on this topic. We found a significant reduction in PPH rates and the use of additional oxytocics with projected overall financial savings of £68.93 per patient with the use of carbetocin. Impact statement It is well established that carbetocin reduces the use of secondary oxytocics compared to oxytocin alone in the active management of the third stage of labour. Evidence for reduction of post-partum haemorrhage and its cost effectiveness are more equivocal. Our study demonstrates that carbetocin also reduces post-partum haemorrhage, use of blood and blood products and midwifery recovery time in the setting of caesarean section. We have also demonstrated that despite the increased index cost of carbetocin it delivers an overall substantial cost benefit. The implications of these findings are of reduced morbidity, faster recovery and cost savings in these times of austerity in the UK. It allows more efficient labour distribution of midwives, particularly in the setting of staff shortages across the NHS. A randomised control trial in this area needs to be conducted to determine the cost benefit of carbetocin and with this and post-partum haemorrhage rates as the primary outcome measures.

In Vitro Comparative Effect of Carbetocin and Oxytocin in Pregnant Human Myometrium with and without Oxytocin Pretreatment

Background

The purpose of this study was to compare in vitro contractile effects of oxytocin and carbetocin on human term pregnant myometrium with and without oxytocin pretreatment.

Methods

This laboratory investigation was conducted on myometrial samples from women undergoing elective cesarean deliveries. The samples were dissected into four strips and suspended in individual organ bath chambers containing physiologic salt solution. After equilibration, they were pretreated with oxytocin 10−5 M (experimental group) or physiologic salt solution (control group) for 2 h and then subjected to dose–response testing with increasing concentrations of oxytocin or carbetocin (10−10 to 10−5 M). The amplitude, frequency, motility index (amplitude × frequency), and area under the curve of contractions were recorded and analyzed during the equilibration and dose–response periods. Comparisons were made between oxytocin-induced and carbetocin-induced contractions in control and oxytocin-pretreated groups. Motility index was the primary outcome measure.

Results

Sixty-three experiments were performed (carbetocin, n = 31; oxytocin, n = 32) on samples from 18 women. The motility index of contractions (√g.contractions/10 min) produced by oxytocin was significantly higher than carbetocin in both control (regression-estimated difference, 0.857; 95% CI, 0.290 to 1.425; P = 0.003) and oxytocin-pretreated (0.813; 0.328 to 1.299; P = 0.001) groups. The motility index was significantly lower in oxytocin-pretreated groups than their respective controls for both oxytocin (−1.040; −1.998 to −0.082; P = 0.03) and carbetocin (−0.996; −1.392 to −0.560; P &lt; 0.001).

Conclusions

In vitro contractions produced by oxytocin are superior to carbetocin in human myometrium with or without oxytocin pretreatment. Oxytocin pretreatment results in attenuation of contractions induced by both oxytocin and carbetocin.