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American Journal of Obstetrics and... Mar 2024Oxytocin is a peptide hormone that plays a key role in regulating the female reproductive system, including during labor and lactation. It is produced primarily in the... (Review)
Review
Oxytocin is a peptide hormone that plays a key role in regulating the female reproductive system, including during labor and lactation. It is produced primarily in the hypothalamus and secreted by the posterior pituitary gland. Oxytocin can also be administered as a medication to initiate or augment uterine contractions. To study the effectiveness and safety of oxytocin, previous studies have randomized patients to low- and high-dose oxytocin infusion protocols either alone or as part of an active management of labor strategy along with other interventions. These randomized trials demonstrated that active management of labor and high-dose oxytocin regimens can shorten the length of labor and reduce the incidence of clinical chorioamnionitis. The safety of high-dose oxytocin regimens is also supported by no associated differences in fetal heart rate abnormalities, postpartum hemorrhage, low Apgar scores, neonatal intensive care unit admissions, and umbilical artery acidemia. Most studies reported no differences in the cesarean delivery rates with active management of labor or high-dose oxytocin regimens, thereby further validating its safety. Oxytocin does not have a predictable dose response, thus the pharmacologic effects and the amplitude and frequency of uterine contractions are used as physiological parameters for oxytocin infusion titration to achieve adequate contractions at appropriate intervals. Used in error, oxytocin can cause patient harm, highlighting the importance of precise administration using infusion pumps, institutional safety checklists, and trained nursing staff to closely monitor uterine activity and fetal heart rate changes. In this review, we summarize the physiology, pharmacology, infusion regimens, and associated risks of oxytocin.
Topics: Pregnancy; Infant, Newborn; Humans; Female; Oxytocin; Oxytocics; Labor, Induced; Labor, Obstetric; Cesarean Section
PubMed: 37460365
DOI: 10.1016/j.ajog.2023.06.041 -
Anasthesiologie, Intensivmedizin,... Oct 2023Postpartum hemorrhage (PPH) affects about 4% of all deliveries in high-income countries and continues to rise, a trend attributable to the increase in caesarean section... (Review)
Review
Postpartum hemorrhage (PPH) affects about 4% of all deliveries in high-income countries and continues to rise, a trend attributable to the increase in caesarean section rates and maternal morbidity. Preventive measures such as the precautionary administration of uterotonics effectively reduce the risk of severe bleeding irrespective of birth mode. As a time-critical condition and a significant contributor to adverse maternal outcomes, PPH needs to be diagnosed early by measuring, not estimating, blood losses. Institutional treatment algorithms should be available to guide stage-based interdisciplinary management without delay. The main therapy goals are to identify the etiology and stop the bleeding by using uterotonics and mechanical and surgical interventions, to restore hemodynamic stability by volume and transfusion therapy and to optimize hemostasis by laboratory- and viscoelastic assay-guided factor replacement. This review highlights current recommendations for prevention, diagnosis and treatment of PPH.
Topics: Pregnancy; Female; Humans; Postpartum Hemorrhage; Oxytocics; Cesarean Section; Blood Transfusion
PubMed: 37832561
DOI: 10.1055/a-2043-4451 -
Best Practice & Research. Clinical... May 2022Uterotonics play an important role in the management of postpartum haemorrhage (PPH), often caused by uterine atony. The World Health Organization (WHO) recommends the...
Uterotonics play an important role in the management of postpartum haemorrhage (PPH), often caused by uterine atony. The World Health Organization (WHO) recommends the application of uterotonics for all births. Oxytocin, considered the first-line uterotonic, binds to a G protein-coupled receptor which is subject to down sensitization upon repeated or prolonged administration of oxytocin. Consequently, a uterotonic with a different mechanism of action should be chosen early when oxytocin does not restore uterine tone. Choice of the second-line uterotonic is determined by institutional preferences as well as by maternal co-morbidities since most uterotonics have cardiovascular side effects. Slow injection of all uterotonics is strongly recommended to blunt these reactions. Methylergometrine and carboprost should, therefore, be avoided in many cardiovascular pathologies. Carbetocin is a chemical modification of oxytocin with a longer half-time, and therefore one bolus of carbetocin is usually sufficient. Its heat stability makes it an ideal candidate in resource-restricted settings.
Topics: Drug-Related Side Effects and Adverse Reactions; Female; Humans; Oxytocics; Oxytocin; Postpartum Hemorrhage
PubMed: 35659950
DOI: 10.1016/j.bpa.2022.02.002 -
Lancet (London, England) Sep 2020The anti-progesterone drug mifepristone and the prostaglandin misoprostol can be used to treat missed miscarriage. However, it is unclear whether a combination of... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
The anti-progesterone drug mifepristone and the prostaglandin misoprostol can be used to treat missed miscarriage. However, it is unclear whether a combination of mifepristone and misoprostol is more effective than administering misoprostol alone. We investigated whether treatment with mifepristone plus misoprostol would result in a higher rate of completion of missed miscarriage compared with misoprostol alone.
METHODS
MifeMiso was a multicentre, double-blind, placebo-controlled, randomised trial in 28 UK hospitals. Women were eligible for enrolment if they were aged 16 years and older, diagnosed with a missed miscarriage by pelvic ultrasound scan in the first 14 weeks of pregnancy, chose to have medical management of miscarriage, and were willing and able to give informed consent. Participants were randomly assigned (1:1) to a single dose of oral mifepristone 200 mg or an oral placebo tablet, both followed by a single dose of vaginal, oral, or sublingual misoprostol 800 μg 2 days later. Randomisation was managed via a secure web-based randomisation program, with minimisation to balance study group assignments according to maternal age (<30 years vs ≥30 years), body-mass index (<35 kg/mvs ≥35 kg/m), previous parity (nulliparous women vs parous women), gestational age (<70 days vs ≥70 days), amount of bleeding (Pictorial Blood Assessment Chart score; ≤2 vs ≥3), and randomising centre. Participants, clinicians, pharmacists, trial nurses, and midwives were masked to study group assignment throughout the trial. The primary outcome was failure to spontaneously pass the gestational sac within 7 days after random assignment. Primary analyses were done according to intention-to-treat principles. The trial is registered with the ISRCTN registry, ISRCTN17405024.
FINDINGS
Between Oct 3, 2017, and July 22, 2019, 2595 women were identified as being eligible for the MifeMiso trial. 711 women were randomly assigned to receive either mifepristone and misoprostol (357 women) or placebo and misoprostol (354 women). 696 (98%) of 711 women had available data for the primary outcome. 59 (17%) of 348 women in the mifepristone plus misoprostol group did not pass the gestational sac spontaneously within 7 days versus 82 (24%) of 348 women in the placebo plus misoprostol group (risk ratio [RR] 0·73, 95% CI 0·54-0·99; p=0·043). 62 (17%) of 355 women in the mifepristone plus misoprostol group required surgical intervention to complete the miscarriage versus 87 (25%) of 353 women in the placebo plus misoprostol group (0·71, 0·53-0·95; p=0·021). We found no difference in incidence of adverse events between the study groups.
INTERPRETATION
Treatment with mifepristone plus misoprostol was more effective than misoprostol alone in the management of missed miscarriage. Women with missed miscarriage should be offered mifepristone pretreatment before misoprostol to increase the chance of successful miscarriage management, while reducing the need for miscarriage surgery.
FUNDING
UK National Institute for Health Research Health Technology Assessment Programme.
Topics: Abortion, Missed; Adult; Double-Blind Method; Drug Therapy, Combination; Humans; Mifepristone; Misoprostol; Oxytocics; Treatment Outcome
PubMed: 32853559
DOI: 10.1016/S0140-6736(20)31788-8 -
Best Practice & Research. Clinical... Nov 2021The inexorable rise in induction rates over the past two decades, in parallel with increasing medical costs and pressure to reduce length of stay, has led to marked... (Review)
Review
The inexorable rise in induction rates over the past two decades, in parallel with increasing medical costs and pressure to reduce length of stay, has led to marked logistic difficulties for health care workers, managers and planners. Maternity services are being overwhelmed by the need to allocate staff and delivery suite space for the scheduling and undertaking of induction processes, rather than focussing care for women in spontaneous labour. Induction of labour according to the majority of current protocols and guidelines necessitates increased length of stay and relatively aggressive use of oxytocin (to reduce the time expended in the labour ward from artificial rupture of membranes (AROM) to establishment of labour). This increased oxytocin usage requires increased use of continuous electronic foetal monitoring, and may also increase epidural usage, further increasing the complexity of labour for the woman and her health care workers. Outpatient care after cervical priming and even outpatient care after AROM may help to ease these pressures and may reduce the medicalisation of the birth experience when induction is indicated, with a potential to reduce oxytocin use and associated interventions. If the period between cervical priming to AROM is managed as outpatient care, then the woman may be able to find better psychological and social support at home, as well as maintain autonomy and get better rest prior to the onset of labour. Inpatient AROM could also be followed by outpatient care until the pregnant person returns to the hospital, either in spontaneous labour, or for initiation of syntocinon after 12-18 h. High-quality research has already demonstrated that outpatient care for cervical ripening is acceptable to mothers and caregivers, has economic benefits and has an acceptable safety profile in appropriately selected low-risk inductions.
Topics: Cervical Ripening; Female; Humans; Labor, Induced; Outpatients; Oxytocics; Oxytocin; Pregnancy
PubMed: 34556409
DOI: 10.1016/j.bpobgyn.2021.08.005 -
American Journal of Obstetrics and... May 2022Early amniotomy shortens the duration of spontaneous labor, yet there is no clear evidence on the optimal timing of amniotomy following cervical ripening. There are... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Early amniotomy shortens the duration of spontaneous labor, yet there is no clear evidence on the optimal timing of amniotomy following cervical ripening. There are limited high-quality studies on the use of early amniotomy intervention following labor induction.
OBJECTIVE
This study aimed to evaluate whether amniotomy within 1 hour of Foley catheter expulsion reduces the duration of labor among individuals undergoing combined misoprostol and Foley catheter labor induction at term.
STUDY DESIGN
This was a randomized clinical trial conducted from November 2020 to May 2021 comparing amniotomy within 1 hour of Foley catheter expulsion (early artificial rupture of membranes) with expectant management. Randomization was stratified by parity. Labor management was standardized among participants. Individuals undergoing induction at ≥37 weeks with a singleton gestation and needing cervical ripening were eligible. Our primary outcome was time to delivery. Wilcoxon rank sum, Pearson chi-square, and Cox survival analyses with intent-to-treat principles were performed adjusting for age, body mass index, parity, mode of delivery, Bishop score, and the interaction between randomization group and parity. A sample size of 160 was planned to detect a 4-hour reduction in delivery time.
RESULTS
A total of 160 patients (79 early artificial rupture of membranes, 81 expectant management) were randomized. Early artificial rupture of membranes achieved a faster median time to delivery than expectant management (early artificial rupture of membranes: 11.1 hours; interquartile range, 6.25-17.1 vs expectant management: 19.8 hours; interquartile range, 13.2-26.2; P<.001). A greater percentage of individuals in the early artificial rupture of membranes group delivered within 24 hours (86% vs 70%; P=.03). There was no difference in the cesarean delivery rate between the 2 groups (22% vs 31%; P=.25). Individuals delivered 2.3 times faster following early artificial rupture of membranes (hazard ratio, 2.3; 95% confidence interval, 1.5-3.4; P<.001). There were no significant differences in maternal and neonatal outcomes.
CONCLUSION
Amniotomy within 1 hour of Foley catheter expulsion resulted in 2.3 times faster delivery than expectant management. Therefore, early artificial rupture of membranes should be considered in individuals undergoing mechanical cervical ripening at term.
Topics: Amniotomy; Catheters; Cervical Ripening; Female; Humans; Infant, Newborn; Labor, Induced; Misoprostol; Oxytocics; Pregnancy
PubMed: 35135684
DOI: 10.1016/j.ajog.2021.11.1368 -
The Cochrane Database of Systematic... Nov 2020Postpartum haemorrhage (PPH), defined as a blood loss of 500 mL or more after birth, is the leading cause of maternal death worldwide. The World Health Organization... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Postpartum haemorrhage (PPH), defined as a blood loss of 500 mL or more after birth, is the leading cause of maternal death worldwide. The World Health Organization (WHO) recommends that all women giving birth should receive a prophylactic uterotonic agent. Despite the routine administration of a uterotonic agent for prevention, PPH remains a common complication causing one-quarter of all maternal deaths globally. When prevention fails and PPH occurs, further administration of uterotonic agents as 'first-line' treatment is recommended. However, there is uncertainty about which uterotonic agent is best for the 'first-line' treatment of PPH.
OBJECTIVES
To identify the most effective uterotonic agent(s) with the least side-effects for PPH treatment, and generate a meaningful ranking among all available agents according to their relative effectiveness and side-effect profile.
SEARCH METHODS
We searched the Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (5 May 2020), and the reference lists of all retrieved studies.
SELECTION CRITERIA
All randomised controlled trials or cluster-randomised trials comparing the effectiveness and safety of uterotonic agents with other uterotonic agents for the treatment of PPH were eligible for inclusion.
DATA COLLECTION AND ANALYSIS
Two review authors independently assessed all trials for inclusion, extracted data and assessed each trial for risk of bias. Our primary outcomes were additional blood loss of 500 mL or more after recruitment to the trial until cessation of active bleeding and the composite outcome of maternal death or severe morbidity. Secondary outcomes included blood loss-related outcomes, morbidity outcomes, and patient-reported outcomes. We performed pairwise meta-analyses and indirect comparisons, where possible, but due to the limited number of included studies, we were unable to conduct the planned network meta-analysis. We used the GRADE approach to assess the certainty of evidence.
MAIN RESULTS
Seven trials, involving 3738 women in 10 countries, were included in this review. All trials were conducted in hospital settings. Randomised women gave birth vaginally, except in one small trial, where women gave birth either vaginally or by caesarean section. Across the seven trials (14 trial arms) the following agents were used: six trial arms used oxytocin alone; four trial arms used misoprostol plus oxytocin; three trial arms used misoprostol; one trial arm used Syntometrine® (oxytocin and ergometrine fixed-dose combination) plus oxytocin infusion. Pairwise meta-analysis of two trials (1787 participants), suggests that misoprostol, as first-line treatment uterotonic agent, probably increases the risk of blood transfusion (risk ratio (RR) 1.47, 95% confidence interval (CI) 1.02 to 2.14, moderate-certainty) compared with oxytocin. Low-certainty evidence suggests that misoprostol administration may increase the incidence of additional blood loss of 1000 mL or more (RR 2.57, 95% CI 1.00 to 6.64). The data comparing misoprostol with oxytocin is imprecise, with a wide range of treatment effects for the additional blood loss of 500 mL or more (RR 1.66, 95% CI 0.69 to 4.02, low-certainty), maternal death or severe morbidity (RR 1.98, 95% CI 0.36 to 10.72, low-certainty, based on one study n = 809 participants, as the second study had zero events), and the use of additional uterotonics (RR 1.30, 95% CI 0.57 to 2.94, low-certainty). The risk of side-effects may be increased with the use of misoprostol compared with oxytocin: vomiting (2 trials, 1787 participants, RR 2.47, 95% CI 1.37 to 4.47, high-certainty) and fever (2 trials, 1787 participants, RR 3.43, 95% CI 0.65 to 18.18, low-certainty). According to pairwise meta-analysis of four trials (1881 participants) generating high-certainty evidence, misoprostol plus oxytocin makes little or no difference to the use of additional uterotonics (RR 0.99, 95% CI 0.94 to 1.05) and to blood transfusion (RR 0.95, 95% CI 0.77 to 1.17) compared with oxytocin. We cannot rule out an important benefit of using the misoprostol plus oxytocin combination over oxytocin alone, for additional blood loss of 500 mL or more (RR 0.84, 95% CI 0.66 to 1.06, moderate-certainty). We also cannot rule out important benefits or harms for additional blood loss of 1000 mL or more (RR 0.76, 95% CI 0.43 to 1.34, moderate-certainty, 3 trials, 1814 participants, one study reported zero events), and maternal mortality or severe morbidity (RR 1.09, 95% CI 0.35 to 3.39, moderate-certainty). Misoprostol plus oxytocin increases the incidence of fever (4 trials, 1866 participants, RR 3.07, 95% CI 2.62 to 3.61, high-certainty), and vomiting (2 trials, 1482 participants, RR 1.85, 95% CI 1.16 to 2.95, high-certainty) compared with oxytocin alone. For all outcomes of interest, the available evidence on the misoprostol versus Syntometrine® plus oxytocin combination was of very low-certainty and these effects remain unclear. Although network meta-analysis was not performed, we were able to compare the misoprostol plus oxytocin combination with misoprostol alone through the common comparator of oxytocin. This indirect comparison suggests that the misoprostol plus oxytocin combination probably reduces the risk of blood transfusion (RR 0.65, 95% CI 0.42 to 0.99, moderate-certainty) and may reduce the risk of additional blood loss of 1000 mL or more (RR 0.30, 95% CI 0.10 to 0.89, low-certainty) compared with misoprostol alone. The combination makes little or no difference to vomiting (RR 0.75, 95% CI 0.35 to 1.59, high-certainty) compared with misoprostol alone. Misoprostol plus oxytocin compared to misoprostol alone are compatible with a wide range of treatment effects for additional blood loss of 500 mL or more (RR 0.51, 95% CI 0.20 to 1.26, low-certainty), maternal mortality or severe morbidity (RR 0.55, 95% CI 0.07 to 4.24, low-certainty), use of additional uterotonics (RR 0.76, 95% CI 0.33 to 1.73, low-certainty), and fever (RR 0.90, 95% CI 0.17 to 4.77, low-certainty).
AUTHORS' CONCLUSIONS
The available evidence suggests that oxytocin used as first-line treatment of PPH probably is more effective than misoprostol with less side-effects. Adding misoprostol to the conventional treatment of oxytocin probably makes little or no difference to effectiveness outcomes, and is also associated with more side-effects. The evidence for most uterotonic agents used as first-line treatment of PPH is limited, with no evidence found for commonly used agents, such as injectable prostaglandins, ergometrine, and Syntometrine®.
Topics: Bias; Blood Transfusion; Confidence Intervals; Drug Therapy, Combination; Ergonovine; Female; Humans; Misoprostol; Network Meta-Analysis; Oxytocics; Oxytocin; Postpartum Hemorrhage; Pregnancy; Randomized Controlled Trials as Topic
PubMed: 33232518
DOI: 10.1002/14651858.CD012754.pub2 -
Medicine Nov 2019To evaluate the efficacy and safety of carbetocin for prevention of postpartum hemorrhage in women undergoing vaginal delivery compared with oxytocin. (Comparative Study)
Comparative Study Meta-Analysis
OBJECTIVE
To evaluate the efficacy and safety of carbetocin for prevention of postpartum hemorrhage in women undergoing vaginal delivery compared with oxytocin.
METHODS
We conducted a systemic literature search in PubMed, the Cochrane Library, and Embase without language restrictions from inception of each of database to November 18th, 2018. Randomized controlled trials with outcome measure of blood loss ≥500 ml were eligible if they compared carbetocin with oxytocin to prevent postpartum hemorrhage during the third stage of labor in women undergoing vaginal delivery.
RESULTS
This meta-analysis of 5 randomized controlled trials (30,314 women) indicated that there was no significant difference between carbetocin and oxytocin in blood loss ≥500 ml in women undergoing vaginal delivery (relative risks (RRs), 0.52; 95% confidence intervals (CIs), 0.24 to 1.15; P = .11; I = 69%). Sensitivity analyses showed the same results. No significant differences were found in blood loss ≥1000 ml, use of additional uterotonic agents, blood transfusion, uterine massage, flushing, vomiting, abdominal pain, nausea, dizziness, headache, palpitation, itching, and shivering.
CONCLUSIONS
This meta-analysis showed that carbetocin was as effective and safe as oxytocin for prevention of postpartum hemorrhage in women undergoing vaginal delivery, and the choice of carbetocin for routine prophylaxis will depend on cost-effectiveness.
Topics: Delivery, Obstetric; Female; Humans; Oxytocics; Oxytocin; Postpartum Hemorrhage; Pregnancy; Randomized Controlled Trials as Topic; Treatment Outcome
PubMed: 31764790
DOI: 10.1097/MD.0000000000017911 -
Anaesthesia Oct 2019It is routine to give a uterotonic drug following delivery of the neonate during caesarean section. However, there is much heterogeneity in the relevant research, which...
It is routine to give a uterotonic drug following delivery of the neonate during caesarean section. However, there is much heterogeneity in the relevant research, which has largely been performed in low-risk elective cases or women with uncomplicated labour. This is reflected in considerable variation in clinical practice. There are significant differences between dose requirements during elective and intrapartum caesarean section. Standard recommended doses are higher than required, with the potential for acute cardiovascular adverse effects. We recommend a small initial bolus dose of oxytocin, followed by a titrated infusion. The recommended doses of oxytocin may have to be increased in women with risk factors for uterine atony. Carbetocin at equipotent doses to oxytocin has similar actions, while avoiding the requirement for a continuous infusion after the initial dose and reducing the need for additional uterotonics. As with oxytocin, carbetocin dose requirements are higher for intrapartum caesarean sections. A second-line agent should be considered early if oxytocin/carbetocin fails to produce good uterine tone. Women with cardiac disease may be very sensitive to the adverse effects of oxytocin and other uterotonics, and their management needs to be individualised.
Topics: Adult; Cesarean Section; Consensus; Female; Guidelines as Topic; Humans; Infant, Newborn; Oxytocics; Oxytocin; Pregnancy
PubMed: 31347151
DOI: 10.1111/anae.14757 -
MCN. the American Journal of Maternal... 2020
Topics: Adult; Dystocia; Female; Humans; Oxytocics; Oxytocin; Pregnancy
PubMed: 33074919
DOI: 10.1097/NMC.0000000000000659