Does route matter? Impact of route of oxytocin administration on postpartum bleeding: A double-blind, randomized controlled trial

Third stage of labor: evidence-based practice for prevention of adverse maternal and neonatal outcomes

The third stage of labor is defined as the time period between delivery of the fetus through delivery of the placenta. During a normal third stage, uterine contractions lead to separation and expulsion of the placenta from the uterus. Postpartum hemorrhage is a relatively common complication of the third stage of labor. Strategies have been studied to mitigate the risk of postpartum hemorrhage, leading to the widespread implementation of active management of the third stage of labor. Initially, active management of the third stage of labor consisted of a bundle of interventions including administration of a uterotonic agent, early cord clamping, controlled cord traction, and external uterine massage. However, the effectiveness of these interventions as a bundle has been questioned, leading to abandonment of some components in recent years. Despite this, upon review of selected international guidelines, we found that the term "active management of the third stage of labor" was still used, but recommendations for and against individual interventions were variable and not necessarily supported by current evidence. In this review, we: (1) examine the physiology of the third stage of labor, (2) present evidence related to interventions that prevent postpartum hemorrhage and promote maternal and neonatal health, (3) review current global guidelines and recommendations for practice, and (4) propose future areas of investigation. The interventions in this review include pharmacologic agents to prevent postpartum hemorrhage, cord clamping, cord milking, cord traction, cord drainage, early skin-to-skin contact, and nipple stimulation. Treatment of complications of the third stage of labor is outside of the scope of this review. We conclude that current evidence supports the use of effective pharmacologic postpartum hemorrhage prophylaxis, delayed cord clamping, early skin-to-skin contact, and controlled cord traction at delivery when feasible. The most effective uterotonic regimens for preventing postpartum hemorrhage after vaginal delivery include oxytocin plus ergometrine; oxytocin plus misoprostol; or carbetocin. After cesarean delivery, carbetocin or oxytocin as a bolus are the most effective regimens. There is inconsistent evidence regarding the use of tranexamic acid in addition to a uterotonic compared with a uterotonic alone for postpartum hemorrhage prevention after all deliveries. Because of differences in patient comorbidities, costs, and availability of resources and staff, decisions to use specific prevention strategies are dependent on patient- and system-level factors. We recommend that the term "active management of the third stage of labor" as a combined intervention no longer be used. Instead, we recommend that "third stage care" be adopted, which promotes the implementation of evidence-based interventions that incorporate practices that are safe and beneficial for both the woman and neonate.

Side-effects of intravenously versus intramuscularly oxytocin for postpartum hemorrhage: a systematic review and meta-analysis of randomized controlled trials

Background: Oxytocin is the gold standard uterotonic agent for prevention of postpartum hemorrhage. However, there is no consensus with clear evidence about the side-effects of oxytocin administered intravenously or intramuscularly for management of the third stage of labor. We conducted a systematic review and meta-analysis of randomized controlled trials to evaluate the side-effects of intravenously or intramuscularly oxytocin for preventing postpartum hemorrhage in the third stage of labor. Methods: Six representative databases were searched from the inception to July 2023. Randomized controlled trials which explored the intravenously and intramuscularly oxytocin and provided at least one side-effect were included. Statistical analysis included random or fixed-effect meta-analyses using relative risk. Results: Nine studies included, involving 8,295 participants. Ten types of side-effects were reported. There was no statistical difference in hypotension (RR = 1.01, 95%CI = 0.88-1.15), anemia (0.98, 0.83-1.15), tachycardia (0.90, 0.69-1.17), shivering (0.90, 0.69-1.17), headache (0.86, 0.31-2.37), nausea (0.70, 0.20-2.42), vomiting (0.97, 0.26-3.58), uvular edema (0.82, 0.23-2.91), diarrhea (0.97, 0.26-3.58), and fever (0.97, 0.26-3.58) between intravenously or intramuscularly groups. Conclusion: There are no significant differences of side-effects between intravenously and intramuscularly administration of oxytocin for preventing postpartum hemorrhage in the third labor. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=407571.

Prevention of postpartum hemorrhage in vaginal deliveries

Identification of patients at risk for postpartum hemorrhage (PPH) may allow for prompt diagnosis and intervention. Individual risk factors, risk assessment tools and prediction models have been used for determining a patient's risk of PPH. Measures for the prevention of PPH include identification and management of iron deficiency anemia, unit readiness and preparedness through performing regular simulations and having a PPH cart or medication kit readily available, prophylactic uterotonic - carbetocin alone or dual agents such as oxytocin and misoprostol or oxytocin and methylergometrine or antifibrinolytic (oxytocin and tranexamic acid) use in the third stage of labor immediately after fetal head delivery, and controlled cord traction.

Evidence-based labor management: third stage of labor (part 5)

During the third stage of labor, oxytocin and tranexamic acid, oxytocin and misoprostol, oxytocin and methylergometrine, or carbetocin is recommended for the prevention of postpartum hemorrhage after vaginal delivery. Intravenous oxytocin (10 IU) immediately after delivery of the neonate (after either anterior shoulder or whole-body delivery) and before delivery of the placenta is recommended. If oxytocin and tranexamic acid combination is chosen, intravenous tranexamic acid (1 g) in addition to intravenous oxytocin (10 IU) immediately after delivery of the neonate and before placental delivery is recommended. If oxytocin and misoprostol combination is chosen, sublingual misoprostol (400 µg) in addition to intravenous oxytocin (10 IU) immediately after delivery of the neonate is recommended. If there is no intravenous access or if in low-resource settings, sublingual misoprostol (400 µg) and intramuscular oxytocin (10 IU) are recommended. If oxytocin and methylergometrine combination is chosen, intramuscular methylergometrine (0.2 mg) and intravenous oxytocin (10 IU) immediately after delivery of the neonate are recommended. Single-dose intravenous or intramuscular carbetocin (100 µg) immediately after delivery of the neonate is recommended. Controlled cord traction and delayed cord clamping for approximately 60 seconds is recommended. There is insufficient evidence to support or refute umbilical cord milking, uterine massage, or nipple stimulation for the prevention of postpartum hemorrhage. Repair of first- and second-degree lacerations with continuous synthetic suture technique is recommended. No repair of first-degree lacerations if hemostatic and normal cosmesis can be considered. Repair of third-degree lacerations with end-to-end or overlap continuous synthetic suture technique is recommended. Repair of fourth-degree lacerations with delayed absorbable 4-0 or 3-0 polyglactin or chromic suture in a running fashion is recommended. The use of single-dose second-generation cephalosporin at the time of third- or fourth-degree laceration repairs can be considered. Skin-to-skin contact after delivery is recommended. There is insufficient evidence to support or refute routine cord blood gas sampling after delivery. Public cord blood banking is recommended.

Route of postpartum oxytocin administration and maternal hemoglobin decline - A randomized controlled trial

OBJECTIVE

Oxytocin uterotonic agents are routinely administered during the third stage of labor, however, the administration route is varying, intravenously or intramuscularly. We aimed to compare the effect of different regimens of postpartum oxytocin administration on hemoglobin (Hb) and hematocrit (Hct) decline.

METHODS

A randomized, 3-arm study of women who delivered vaginally at term in a single tertiary medical center was conducted. Immediately following the delivery of the fetus women randomly received one of 3 oxytocin regimens: 1) intramuscular 10units (IM group); 2) intravenous 10units in 100 ml 0.9%NaCl solution over 10-15 min (IV group); or 3) combined IV + IM regimens (IV + IM group). Primary outcome was defined as the level of Hb decline between prepartum and postpartum measurements.

RESULTS

Overall, 210 women (70 in each group) were randomized, with 171 included in the final analysis (IM group-61, IV group-57, IV + IM group-53). There was no significant difference between the groups regarding maternal age, pre-pregnancy body-mass-index (BMI), parity, operative vaginal deliveries rate, the rate of episiotomy or perineal tears or neonatal birthweight. Mean prepartum Hb and Hct level were 12.3 ± 1.1 g/dl and 36.9 ± 2.7%, respectively, with no significant difference between the groups. Mean postpartum HB and Hct decline was 1.3 ± 0.8 g/dl and 3.7 ± 2.3%, respectively, with no difference between the groups. In multivariable analysis after adjusting for parity, pre-pregnancy BMI, labor induction, episiotomy or perineal tears and neonatal birthweight, oxytocin regimen was not associated with any difference in hematological measurements.

CONCLUSION

Postpartum Hb and Hct decline was usually minor following vaginal deliveries, and was not affected by postpartum oxytocin regimen.

Intravenous versus intramuscular prophylactic oxytocin for the third stage of labour

BACKGROUND

There is general agreement that oxytocin given either through the intravenous or intramuscular route is effective in reducing postpartum blood loss. However, it is unclear whether the subtle differences between the mode of action of these routes have any effect on maternal and infant outcomes. This review was first published in 2012 and last updated in 2018.

OBJECTIVES

To determine the comparative effectiveness and safety of oxytocin administered intravenously or intramuscularly for prophylactic management of the third stage of labour after vaginal birth.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (19 December 2019), and reference lists of retrieved studies.

SELECTION CRITERIA

Eligible studies were randomised trials comparing intravenous with intramuscular oxytocin for prophylactic management of the third stage of labour after vaginal birth. We excluded quasi-randomised trials.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion and risk of bias, extracted data and checked them for accuracy. We assessed the certainty of the evidence with the GRADE approach.

MAIN RESULTS

Seven trials, involving 7817 women, met the inclusion criteria for this review. The trials compared intravenous versus intramuscular administration of oxytocin just after the birth of the anterior shoulder or soon after the birth of the baby. All trials were conducted in hospital settings and included women with term pregnancies, undergoing a vaginal birth. Overall, the included studies were at moderate or low risk of bias, with two trials providing clear information on allocation concealment and blinding. For GRADE outcomes, the certainty of the evidence was generally moderate to high, except from two cases where the certainty of the evidence was either low or very low. High-certainty evidence suggests that intravenous administration of oxytocin in the third stage of labour compared with intramuscular administration carries a lower risk for postpartum haemorrhage (PPH) ≥ 500 mL (average risk ratio (RR) 0.78, 95% confidence interval (CI) 0.66 to 0.92; six trials; 7731 women) and blood transfusion (average RR 0.44, 95% CI 0.26 to 0.77; four trials; 6684 women). Intravenous administration of oxytocin probably reduces the risk of PPH ≥ 1000 mL, although the 95% CI crosses the line of no-effect (average RR 0.65, 95% CI 0.39 to 1.08; four trials; 6681 women; moderate-certainty evidence). In all studies but one, there was a reduction in the risk of PPH ≥ 1000 mL with intravenous oxytocin. The study that found a large increase with intravenous administration was small (256 women), and contributed only 3% of total events. Once this small study was removed from the meta-analysis, heterogeneity was eliminated and the treatment effect favoured intravenous oxytocin (average RR 0.61, 95% CI 0.42 to 0.88; three trials; 6425 women; high-certainty evidence). Additionally, a sensitivity analysis, exploring the effect of risk of bias by restricting analysis to those studies rated as 'low risk of bias' for random sequence generation and allocation concealment, found that the prophylactic administration of intravenous oxytocin reduces the risk for PPH ≥ 1000 mL, compared with intramuscular oxytocin (average RR 0.64, 95% CI 0.43 to 0.94; two trials; 1512 women). The two routes of oxytocin administration may be comparable in terms of additional uterotonic use (average RR 0.78, 95% CI 0.49 to 1.25; six trials; 7327 women; low-certainty evidence). Although intravenous compared with intramuscular administration of oxytocin probably results in a lower risk for serious maternal morbidity (e.g. hysterectomy, organ failure, coma, intensive care unit admissions), the confidence interval suggests a substantial reduction, but also touches the line of no-effect. This suggests that there may be no reduction in serious maternal morbidity (average RR 0.47, 95% CI 0.22 to 1.00; four trials; 7028 women; moderate-certainty evidence). Most events occurred in one study from Ireland reporting high dependency unit admissions, whereas in the remaining three studies there was only one case of uvular oedema. There were no maternal deaths reported in any of the included studies (very low-certainty evidence). There is probably little or no difference in the risk of hypotension between intravenous and intramuscular administration of oxytocin (RR 1.01, 95% CI 0.88 to 1.15; four trials; 6468 women; moderate-certainty evidence). Subgroup analyses based on the mode of administration of intravenous oxytocin (bolus injection or infusion) versus intramuscular oxytocin did not show any substantial differences on the primary outcomes. Similarly, additional subgroup analyses based on whether oxytocin was used alone or as part of active management of the third stage of labour (AMTSL) did not show any substantial differences between the two routes of administration.

AUTHORS' CONCLUSIONS

Intravenous administration of oxytocin is more effective than its intramuscular administration in preventing PPH during vaginal birth. Intravenous oxytocin administration presents no additional safety concerns and has a comparable side effects profile with its intramuscular administration. Future studies should consider the acceptability, feasibility and resource use for the intervention, especially in low-resource settings.

A meta-analysis of the effects of intramuscular and intravenous injection of oxytocin on the third stage of labor

BACKGROUND

Clinical studies and trials have shown that oxytocin can effectively reduce postpartum bleeding, whether by intramuscular (IM) injection or intravenous (IV) injection. These two methods are widely used in the prevention and treatment for the third stage of childbirth. However, it is unclear whether the subtle differences between the mode of these routes have any effect on maternal outcomes.

OBJECTIVES

To systematically evaluate the efficacy and safety of oxytocin administered intramuscularly or intravenously for prophylactic management of the third stage of labor after vaginal birth.

METHODS

Computerized retrieval of PubMed, the Cochrane Library, Web of Science, Embase, and ClinicalTrials.gov was conducted to collect randomized controlled trials (RCT) on the effects of IM and IV oxytocin on the third stage of labor. After independent literature screening, data extraction and evaluation of the bias risk of included studies by two evaluators, RevMan 5.3 software was used for a meta-analysis.

RESULTS

Six studies with 7734 women were included in this study. Meta-analysis results showed that: the severe postpartum hemorrhage (PPH) rate [risk ratio (RR) 1.54, 95% confidence interval (95% CI) 1.08-2.20, P = 0.02], PPH rate (RR 1.31, 95% CI 1.11-1.55, P = 0.001), incidence of blood transfusion (RR 2.30, 95% CI 1.35-3.93, P = 0.002) and the need of manual removal of placenta (RR 1.44, 95% CI 1.05-1.96, P = 0.02) for IM group were higher than IV group, but there were no significant differences in the use of additional uterotonics (P = 0.31) and the incidence of serious maternal morbidity and adverse effects between two groups. None of the included studies reported maternal death.

CONCLUSION

For clinical practice, intravenous injection oxytocin 10 IU may be a good, safe option in the management of the third stage of labor. Medical conditions, available resources, adverse effects, and women' s preferences should also be considered. If an IV line is already in place at delivery, IV administration may be preferable to IM injection.