Maintenance therapy with oxytocin antagonists for inhibiting preterm birth after threatened preterm labour.
BACKGROUND
In some women, an episode of preterm labour settles and does not result in immediate preterm birth. Subsequent treatment with tocolytic agents such as oxytocin receptor antagonists may then have the potential to prevent the recurrence of preterm labour, prolonging gestation, and preventing the adverse consequences of prematurity for the infant.


OBJECTIVE
To assess the effects of maintenance therapy with oxytocin antagonists administered by any route after an episode of preterm labour in order to delay or prevent preterm birth.


METHODS
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (June 2008), sought ongoing and unpublished trials by contacting experts in the field and searched the reference lists of relevant articles.


METHODS
Randomised controlled trials comparing oxytocin antagonists with any alternative tocolytic agent, placebo or no treatment, used for maintenance therapy after an episode of preterm labour.


METHODS
Standard methods of the Cochrane Collaboration and the Cochrane Pregnancy and Childbirth Group were used. Two review authors independently undertook evaluation of methodological quality and extracted trial data.


RESULTS
This review includes one trial of 513 women. When compared with placebo, atosiban did not reduce preterm birth before 37 weeks (risk risk (RR) 0.89; 95% confidence intervals (CI) 0.71 to 1.12), 32 weeks (RR 0.85; 95% CI 0.47 to 1.55), or 28 weeks (RR 0.75; 95% CI 0.28 to 2.01). No difference was shown in neonatal morbidity, or perinatal mortality.


CONCLUSIONS
There is insufficient evidence to support the use of oxytocin receptor antagonists to inhibit preterm birth after a period of threatened or actual preterm labour. Any future trials using oxytocin antagonists or other drugs as maintenance therapy for preventing preterm birth should examine a variety of important infant outcome measures, including reduction of neonatal morbidity and mortality, and long-term infant follow up. Future research should also focus on the pathophysiological pathways that precede preterm labour.
Papatsonis
Dimitri
D
Department of Obstetrics and Gynaecology, Amphia Hospital Breda, Langendijk 75, Breda, Netherlands, 4819 EV. hoog.pap@wxs.nl
Flenady
Vicki
V
Liley
Helen
H
D005260:Female; D006801:Humans; D007752:Obstetric Labor, Premature / Q000517:prevention & control; D011247:Pregnancy; D047928:Premature Birth / Q000517:prevention & control*; D016032:Randomized Controlled Trials as Topic; D018045:Receptors, Oxytocin / Q000037:antagonists & inhibitors*; D015149:Tocolytic Agents / Q000627:therapeutic use*; D014668:Vasotocin / Q000031:analogs & derivatives* / Q000627:therapeutic use
D018045:Receptors, Oxytocin; D015149:Tocolytic Agents; C047046:atosiban; D014668:Vasotocin