Labour induction with an intermediate-dose oxytocin regimen has advantages over a high-dose regimen

High-Dose versus Low-Dose Oxytocin for Labor Augmentation: A Meta-Analysis of Randomized Controlled Trials

Background/Objectives: Although oxytocin administration is recommended for delayed labor progress, there is no consensus over the preferred optimal dose of oxytocin. We aimed to perform a meta-analysis of pregnancy outcomes comparing high-dose versus low-dose oxytocin regimens for augmentation of delayed labor. Methods: PubMed, Embase, and Cochrane databases were systematically searched for studies comparing high-dose with low-dose oxytocin for labor augmentation from inception up to May 2023. The outcomes assessed were cesarean rate, instrumental delivery rate, postpartum hemorrhage, neonatal death, and uterine tachysystole. Subgroup analysis was performed with randomized controlled trials (RCTs) and propensity-matched studies. Statistical analysis was performed using Rstudio. Heterogeneity was assessed with I2 statistics, and a random-risk effect was used if I2 > 50%. Results: Twenty-one studies met inclusion criteria, and eighteen were RCTs. A total of 14.834 patients were included, of whom 7.921 (53.3%) received high-dose and 6.913 (46.6%) received low-dose oxytocin during labor augmentation. No statistical differences were found in cesarean delivery, neonatal mortality, postpartum hemorrhage and vaginal instrumentation rate. However, uterine tachysystole incidence was significantly higher with high-dose oxytocin (95% Cl, 1.30-1.94, p = 0.3; 0.6; I2 = 9%). Conclusions: Labor augmentation with a low-dose oxytocin regimen is effective as with a high-dose regimen, but with significantly less uterine tachysystole events, which can lead to intrauterine and neonatal complications. Our findings suggest that a low-dose regimen may be safe and effective for labor augmentation in medical practice.

Expediting labor induction in severe pre-eclampsia by earlier initiation of oxytocin after cervical ripening: A randomized study from India

OBJECTIVE

To observe whether induction of labor (IoL) among women with severe pre-eclampsia (PE) can be expedited by initiating oxytocin early (after 6 h) than after 12 h following cervical ripening with a combined method.

METHODS

Women with severe PE and Bishop's < 6 (n = 96) were randomized into two groups. All women received cervical ripening with a combined method (intracervical Foley's plus dinoprostone gel 0.5 mg) following which Group 1 women received oxytocin after 6 h (with Foley's in-situ) and Group 2 after 12 h (after removing Foley's) RESULTS: Majority were nulliparous (63% in group 1 and 77% in group 2) and the mean gestation was similar (35.3 ± 2.98 weeks in group 1 and 35.5 ± 3.09 in group 2). Nearly half the women had partial HELLP/ HELLP (47.9% and 54.1%; in groups 1 and 2, respectively). The induction-delivery interval (IDI) was significantly reduced in group 1 (16 h 6 min vs 22 h 6 min in group 2; p = 0.001). The cesarean section (CS) rate was 37.5% in group 1 and 31.3% in group 2 (p = 0.525), but the study was underpowered to assess this outcome. The neonatal outcome was similar, 92/96 neonates were discharged after a hospital stay of 3-52 days. There were 4 neonatal deaths (1 in group 1 and 3 in group 2) of extreme or very preterm neonates (27-30 + 6 wks) with birth weight of 735-965 gm.

CONCLUSION

Among women with severe PE undergoing IoL, initiating oxytocin 6 h after cervical ripening with a combined method reduced the IDI significantly as compared to initiating it after 12 h, with a similar CS rate and neonatal outcome.

Comparison of intracervical Foley catheter combined with a single dose of vaginal misoprostol tablet or intracervical dinoprostone gel for cervical ripening: a randomised study

We compared two combined methods for cervical ripening before induction of labour (IOL) Women (n = 150) were randomised into Foley's-misoprostol (n = 75) and Foley's-dinoprostone (n = 75) groups. A single dose of vaginal misoprostol tablet (25 µg) or intracervical dinoprostone gel (0.5 mg) were used alongwith intracervical Foley's. The primary outcome was induction-delivery interval (IDI) and secondary outcomes were change in Bishop's score, oxytocin requirement, caesarean section (CS) rate, chorioamnionitis and neonatal outcome. The mean parity, gestation and indications for IOL were similar in the two groups. The IDI (19 h 37 min and 19 h 20 min; p = .683), cervical ripening time, oxytocin requirement, CS rate (18.7 and 25.4%, p = .322) and neonatal outcome were similar. Hyperstimulation developed in 2.7% women with Foley's-misoprostol and in 1.3% with Foley's-dinoprostone (p = .55). No woman had chorioamnionitis. Thus, these two combined methods of cervical ripening and IOL were observed to be similarly efficacious. A low incidence of hyperstimulation and no chorioamnionitis may be attributed to using a single dose of prostaglandins. Misoprostol may be substituted for dinoprostone in resource limited countries.Impact statementWhat is already known on this subject? Combined methods for cervical ripening (intracervical Foley's plus prostaglandins) before induction of labour (IOL) may be similarly or more efficacious than individual methods. Most studies comparing various combined methods have used repeated doses of prostaglandins. A combined method using repetitive doses of prostaglandins may increase the risk of hyperstimulation and also of infection consequent to repeated vaginal examination to administer prostaglandins. These two concerns may be offset by combining a single dose of prostaglandin with intracervical Foley's catheter.What do the results of this study add? Two combined methods for cervical ripening using a single dose of vaginal misoprostol (25 µg) or intracervical dinoprostone gel (0.5 mg) co-administered with intracervical Foley's catheter were found to be similarly efficacious. The IDI (19 h 37 min and 19 h 20 min; p = .683), cervical ripening time, oxytocin requirement, CS rate (18.7 and 25.4%, p = .322) and neonatal outcome were similar. The incidence of hyperstimulation was low (2.7 and 1.3% with Foley's-misoprostol and Foley's-dinoprostone, respectively) and no woman had chorioamnionitis.What are the implications of these findings for clinical practice and/or further research? Combined methods for cervical ripening using a single dose of prostaglandins (misoprostol or dinoprostone) were observed to be similarly efficacious. Misoprostol is a cheaper alternative to dinoprostone and may be utilised in resource limited countries. These methods may be compared with each other in more number of women in order to identify which combined method is more efficient and safe. Clinical Trials Registry of India: CTRI/2017/12/010738.

Inter-institutional variations in oxytocin augmentation during labour in German university hospitals: a national survey

BACKGROUND

There are several international guidelines on oxytocin regimens for induction and augmentation of labour, but no agreement on a standardised regimen in Germany. This study collated and reviewed the oxytocin regimens used for labour augmentation in university hospitals, with the long-term aim of contributing to the development of a national clinical guideline.

METHODS

Germany has 34 university hospital compounds, representing 39 maternity units. In this observational study we asked units to provide standard operational procedures on oxytocin augmentation during labour or provide the details in a structured survey. Data were collected on the dosage of oxytocin, type and volume of solutions used, indications and contraindications for use and discontinuation, case-specific administration, and on who developed the procedures. Findings were analysed descriptively.

RESULTS

A total of 35 (90%) units participated in this study. Standard operating procedures were available in 24 units (69%), seven units (20%) did not have procedures and information was missing from four units (11%). Midwives participated in the development of standard operating procedures in 15 units (43%). Infusions were most commonly prepared using six units of oxytocin in 500 ml 0.9% normal saline solution (12 mU/ml). The infusions were started at 120 mU/hour and increased by 120 mU/hour at 20-min intervals up to a maximum dosage of 1200 mU/hour. The most common indication for use was delayed progress in labour. Infusions were stopped when uterine contractions became hypertonic and/or the fetal heart rate showed signs of distress. Most of the practices described aligned with international guidance. All units used reduced oxytocin dosages for women with a history of previous caesareans section, as recommended in the international guidelines, and restrictive use was advised in multiparous women. The main difference between units related to combined use of amniotomy and oxytocin, recommended by three guidelines but used in only four maternity units (11%).

CONCLUSIONS

While there was considerable variation in the oxytocin augmentation procedures, most but not all practices used in these 35 German maternity units were comparable. Establishing a national guideline on the criteria for and administration of oxytocin for augmentation of labour would eliminate the observed differences and minimise risk of administration and medication error.

Early versus delayed amniotomy during labor induction with oxytocin in women with Bishop's score of ≥6: a randomized trial

OBJECTIVE

To study the effect of "early amniotomy" {initiating induction of labor (IOL) with amniotomy followed by oxytocin} versus "late amniotomy" (initiating IOL with oxytocin followed by amniotomy 4-8 h later) in induced labor.

METHODS AND MATERIALS

One hundred and fifty women with Bishop's score of ≥6 undergoing IOL were randomized into "early amniotomy" and "delayed amniotomy".

RESULTS

Early amniotomy resulted in a reduced induction-delivery interval (IDI) (7.35 versus 11.66 h with delayed amniotomy, p = .000) but higher the caesarean section (CS) rate was observed (10.7 versus 2.7% with delayed amniotomy, p = .049). With early amniotomy, the proportion of women delivering within 12 h was higher (86.7 versus 60%, p = .000) and the maximum oxytocin concentration used was lower (30.05 versus 39.68 mU/min, p = .001) as compared to delayed amniotomy. The neonatal outcomes were similar in the two groups. Early amniotomy detected meconium prior to initiating uterine contractions with oxytocin in three women who underwent CS for meconium.

CONCLUSION

Initiating IOL with amniotomy in women with a favorable cervix was efficacious in expediting delivery, but it resulted in a higher CS rate. The higher CS rate was partly due to CS for meconium detected as a result of early amniotomy. Clinical Trials Registry (CTRI), India: Registration number CTRI/2015/01/005418.