MATERIALS AND METHODS: Major electronic databases were searched for randomized-controlled trials comparing carbetocin with oxytocin. Only trials involving cesarean deliveries were included. Non-randomized trials, non-cesarean deliveries, studies which did not directly compare carbetocin to oxytocin and studies which did not analyze the intended outcomes were excluded. Outcomes analysed were postpartum hemorrhage, additional use of uterotonic and transfusion requirement.
RESULTS: Seven studies involving 2012 patients were included in the meta-analysis. There was a significant reduction in the rates of postpartum hemorrhage (RR 0.79; 95% CI 0.66 to 0.94; p = 0.009), use of additional uterotonics (RR 0.57; 95% CI 0.49 to 0.65; p oxytocin was used. There was significant heterogeneity across studies however, for the outcome of additional uterotonic usage.
CONCLUSION: Carbetocin is effective in reducing the use of additional uterotonics, reduction in postpartum hemorrhage and transfusion when used during cesarean deliveries. However, despite the potential benefits illustrated in this meta-analysis, the disparity between the cost of carbetocin and oxytocin suggests that locoregional cost-effectiveness analysis should be performed before any decision is made to adopt it for routine prophylaxis.
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.
DESIGN: randomised controlled trial of nulliparous women with spontaneous labour at term.
SETTING: labour suite of a university teaching hospital in Kuala Lumpur, Malaysia.
PARTICIPANTS: 240 women were included (120 randomised into two arms).
INTERVENTIONS: the randomisation sequence was generated using a computer randomisation program in two blocks: oxytocin infused early following amniotomy; and oxytocin infused 2 h after amniotomy.
MEASUREMENTS AND FINDINGS: labour duration, mode of delivery, oxytocin dosage used, uterine hyperstimulation, postpartum haemorrhage, Apgar score and admission to the neonatal intensive care unit were recorded. No differences in vaginal delivery rate (62.9% vs 70.9%; p = 0.248) and second-stage labour were found between the early and delayed oxytocin infusion groups (21.2 ± 18.3 min vs 25.5 ± 19.9 min; p = 0.220). The mean interval from amniotomy to vaginal delivery was significantly shorter for the early group (5.8 ± 1.7 h vs 7.0 ± 1.9 h; p = 0.001), and more women in the early group delivered during/before the planned review at 4 h after amniotomy (53.6% vs 10.6%; p<0.001). Maximum oxytocin usage was lower in the early group (5.6 ± 4.4 mL/hour vs 6.8 ± 5.3 mL/hour; p = 0.104).
KEY CONCLUSIONS: early oxytocin augmentation following amniotomy could be employed in low-risk primigravida, given that it is associated with a shorter labour duration without jeopardising maternal or neonatal outcomes.
IMPLICATIONS FOR PRACTICE: low-risk primigravida benefit from early oxytocin infusion following amniotomy, and this can be offered as an additional practice in labour room care.
METHODS: : Nulliparas with uncomplicated PROM at term, a Bishop score less than or equal to 6, and who required labor induction were recruited for a double-blind randomized trial. Participants were randomly assigned to 3-mg dinoprostone pessary and oxytocin infusion or placebo and oxytocin infusion. A cardiotocogram was performed before induction and maintained to delivery. Dinoprostone pessary or placebo was placed in the posterior vaginal fornix. Oxytocin intravenous infusion was commenced at 2 milliunits/min and doubled every 30 minutes to a maximum of 32 milliunits/min. Oxytocin infusion rate was titrated to achieve four contractions every 10 minutes. Primary outcomes were vaginal delivery within 12 hours and maternal satisfaction with the birth process using a visual analog scale (VAS) from 0 to 10 (higher score, greater satisfaction).
RESULTS: : One hundred fourteen women were available for analysis. Vaginal delivery rates within 12 hours were 25 of 57 (43.9%) for concurrent treatment compared with 27/57 (47.4%) (relative risk 0.9, 95% confidence interval 0.6-1.4, P=.85) for oxytocin only; median VAS was 8 (interquartile range [IQR] 2) compared with 8 (IQR 2), P=.38. Uterine hyperstimulation was 14% compared with 5.3%, P=.20; overall vaginal delivery rates were 59.6% compared with 64.9%, P=.70; and induction to vaginal delivery interval 9.7 hours compared with 9.4 hours P=.75 for concurrent treatment compared with oxytocin, respectively. There was no significant difference for any other outcome.
CONCLUSION: : Concurrent vaginal dinoprostone and intravenous oxytocin for labor induction of term PROM did not expedite delivery or improve patient satisfaction.
CLINICAL TRIAL REGISTRATION: : Current Controlled Trials, www.controlled-trials.com, ISRCTN74376345
LEVEL OF EVIDENCE: : I.
METHODS: Parous women with favorable cervixes after amniotomy for labor induction were randomized to immediate titrated oxytocin or placebo intravenous infusion in a double-blind noninferiority trial. After 4 hours, study infusions were stopped, the women were assessed, and open-label oxytocin was started if required. Maternal satisfaction with the birth process was assessed with a 10-point visual numerical rating scale (lower score, greater satisfaction).
RESULTS: Vaginal delivery rates at 12 hours were 91 of 96 (94.8%) compared with 91 of 94 (96.8%) (relative risk 0.98, 95% confidence interval [CI] 0.92-1.04, P=.72), and maternal satisfaction on a visual numerical rating scale (median [interquartile range]) was 3 [3-4] compared with 3 [3-5], P=.36 for immediate compared with delayed arm, respectively). Cesarean delivery, maternal fever, postpartum hemorrhage, uterine hyperactivity, and adverse neonatal outcome rates were similar between arms. The immediate oxytocin arm had a shorter amniotomy-to-delivery interval of 5.3±3.1 compared with 6.9±2.9 hours (Poxytocin infusion was avoided by 35.6%.
CONCLUSIONS: Immediate or delayed oxytocin infusions are reasonable options after amniotomy for labor induction in parous women with favorable cervixes. The choice should take into account local resources and the woman's wish.
CLINICAL TRIAL REGISTRATION: ISRCTN Register, http://isrctn.org, ISRCTN51476259.
LEVEL OF EVIDENCE: I.
STUDY DESIGN: Participants were randomized to intravenous bolus injection of 100mcg carbetocin or 10IU oxytocin after cesarean delivery of the baby. The primary outcome is any additional uterotonic which may be administered by the blinded provider for perceived inadequate uterine tone with or without hemorrhage in the first 24hours after delivery. Secondary outcomes include operating time, perioperative blood loss, change in hemoglobin and hematocrit levels, blood transfusion and reoperation for postpartum hemorrhage.
RESULTS: Additional uterotonic rates were 107/276 (38.8%) vs. 155/271 (57.2%) [RR 0.68 95% CI 0.57-0.81 p<0.001; NNTb 6 95% CI 3.8-9.8], mean operating time 45.9±16.0 vs. 44.5±13.1minutes p=0.26, mean blood loss 458±258 vs. 446±281ml p=0.6, severe postpartum hemorrhage (≥1000ml) rates 15/276 (5.4%) vs. 10/271 (3.7%) p=0.33 and blood transfusion rates 6/276 (2.2%) vs. 10/271 (3.7%); p=0.30 for carbetocin and oxytocin arms respectively. There was only one case of re-operation (oxytocin arm). In the cases that needed additional uterotonic 98% (257/262) was started intraoperatively and in 89% (234/262) the only additional uterotonic administered was an oxytocin infusion over 6hours.
CONCLUSION: Fewer women in the carbetocin arm needed additional uterotonics but perioperative blood loss, severe postpartum hemorrhage, blood transfusion and operating time were not different.
METHODS: This randomized trial was conducted in Malaysia in 232 term multiparous women with balloon catheter-ripened cervixes (dilatation ≥3 cm), singleton fetus, cephalic presentation with intact membranes, and reassuring fetal heart rate tracing. They were randomized to immediate titrated intravenous oxytocin infusion and early amniotomy (116) or delayed amniotomy after 4 h of oxytocin (116). Primary outcome was intervention (oxytocin initiation)-to-delivery interval.
RESULTS: Oxytocin-to-delivery intervals were a median of 4.99 h (interquartile range [IQR], 3.21-7.82 h) versus 6.23 h (IQR, 4.50-8.45 h) (P oxytocin infusion were 40 of 116 (35%) versus 22 of 116 (19%) (relative risk [RR], 1.82 [95% confidence interval (CI), 1.16-2.86], P = 0.011) and 77 of 116 (66%) versus 54 of 116 (47%) (RR, 1.43 [95% CI, 1.13-1.80], P = 0.003) for the early versus delayed amniotomy arms, respectively. Maternal satisfaction on birth process were 7 (IQR, 6-8) versus 7 (IQR, 7-8) (P = 0.006), uterine hyperstimulation rates were 10 of 116 (9%) versus 14 of 116 (12%) (RR, 0.71 [95% CI, 0.33-1.54]) (P = 0.519), and Cesarean delivery rates were 17 of 116 (15%) versus 19 of 116 (16%) (RR, 0.90 [95% CI, 0.49-1.63], P = 0.856) for the early versus delayed amniotomy arms, respectively.
CONCLUSION: In multiparas at term following cervical ripening by Foley catheter, immediate oxytocin and early amniotomy compared with a scheduled 4-h delay to amniotomy shortens the interval to birth and decreases uterine hyperactivity in labor but lowers maternal satisfaction. The cesarean delivery rate is not significantly reduced.
CLINICAL TRIAL REGISTRATION: This study was registered with the International Standard Randomised Controlled Trial Number (ISRCTN) on September 29, 2020, with trial identification number: ISRCTN87066007 (https://doi.org/10.1186/ISRCTN87066007). The first participant was recruited on September 29, 2020, after ISRCTN registry confirmation was received.