Continued versus discontinued oxytocin stimulation in the active phase of labour (CONDISOX): double blind randomised controlled trial

Sidsel Boie; Julie Glavind; Niels Uldbjerg; Philip J Steer; Pinar Bor; CONDISOX trial group

doi:10.1136/bmj.n716

Birth and Delivery Labor and Birth

Continued versus discontinued oxytocin stimulation in the active phase of labour (CONDISOX): double blind randomised controlled trial

Boie S, Glavind J, Uldbjerg N, Steer PJ, Bor P, CONDISOX trial group

Published April 14, 2021 BMJ (Clinical research ed.), 373, n716

DOI 10.1136/bmj.n716 PMID 33853878 PMC PMC8044921

RRM Academy Synopsis

Stopping oxytocin cut hyperstimulation; cesarean rates were similar

In a double blind randomized trial, 1200 women in induced labor had cesareans at similar rates after stopping oxytocin (about 17 in 100) or continuing it (about 14 in 100). Stopping cut overactive contractions (3.7% v 12.9%) and added time to delivery (median 282 v 201 minutes).

Key Findings

The cesarean rate was 16.6% (101 of 607) with discontinuation and 14.2% (84 of 591) with continuation, a relative risk of 1.17 (95% CI 0.90 to 1.53).
Uterine hyperstimulation occurred in 3.7% of the discontinued group and 12.9% of the continued group (P<0.001).
Fetal heart rate abnormalities occurred in 27.9% of the discontinued group and 40.8% of the continued group (P<0.001).
Median time from randomization to delivery was 282 minutes with discontinuation and 201 minutes with continuation (P<0.001).
Study medication was stopped for 311 women (51.2%) allocated to discontinuation. Among women allocated to continuation, 197 (33.3%) had it stopped.

Interpretation

The trial was double blind and placebo controlled, run in nine hospitals in Denmark and one in the Netherlands. Participants carried one baby, head down, at term. The authors describe a possible small rise in cesarean births with discontinuation. They note that many women in both groups had the study medication stopped or switched to open label oxytocin, which reduced the power of the comparison. The authors limit their conclusion to a setting where monitoring of the baby and the contractions can be ensured.

RRM Context

Restorative reproductive medicine asks what a treatment does to the body. Here, continued oxytocin was followed by more overactive contractions and more fetal heart rate changes. The trial adds blinded data on that balance.

Our editorial summary of this paper, not the article's abstract.

Abstract

Objective

To determine whether discontinuing oxytocin stimulation in the active phase of induced labour is associated with lower caesarean section rates.

Design

International multicentre, double blind, randomised controlled trial.

Setting

Nine hospitals in Denmark and one in the Netherlands between 8 April 2016 and 30 June 2020.

Participants

1200 women stimulated with intravenous oxytocin infusion during the latent phase of induced labour.

Intervention

Women were randomly assigned to have their oxytocin stimulation discontinued or continued in the active phase of labour.

Main Outcome Measures

Delivery by caesarean section.

Results

A total of 607 women were assigned to discontinuation and 593 to continuation of the oxytocin infusion. The rates of caesarean section were 16.6% (n=101) in the discontinued group and 14.2% (n=84) in the continued group (relative risk 1.17, 95% confidence interval 0.90 to 1.53). In 94 parous women with no previous caesarean section, the caesarean section rate was 7.5% (11/147) in the discontinued group and 0.6% (1/155)in the continued group (relative risk 11.6, 1.15 to 88.7). Discontinuation was associated with longer duration of labour (median from randomisation to delivery 282 v 201 min; P<0.001), a reduced risk of hyperstimulation (20/546 (3.7%) v 70/541 (12.9%); P<0.001), and a reduced risk of fetal heart rate abnormalities (153/548 (27.9%) v 219/537 (40.8%); P<0.001) but rates of other adverse maternal and neonatal outcomes were similar between groups.

Conclusions

In a setting where monitoring of the fetal condition and the uterine contractions can be guaranteed, routine discontinuation of oxytocin stimulation may lead to a small increase in caesarean section rate but a significantly reduced risk of uterine hyperstimulation and abnormal fetal heart rate patterns.

Trial Registration

ClinicalTrials.gov NCT02553226.

Topics

Birth and Delivery › Labor and Birth › Induction of Labor · Therapeutics › Hormonal Agents › Gonadotropins

Sidsel Boie, Julie Glavind, Niels Uldbjerg, Philip J Steer, Pinar Bor

S Boie, J Glavind, N Uldbjerg, Phil Steer, P Steer, P Bor

PMID 33853878 33853878 DOI 10.1136/bmj.n716 10.1136/bmj.n716 Boie et al. 2021, Boie 2021

Correction published 2021

Continued versus discontinued oxytocin stimulation in the active phase of labour (CONDISOX): double blind randomised controlled trial

Stopping oxytocin cut hyperstimulation; cesarean rates were similar

Key Findings

Interpretation

RRM Context

Abstract

Topics

By this author

Risk of stillbirth in low-risk singleton term pregnancies following fertility treatment: a national cohort study

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