Terbutaline pump maintenance therapy after threatened preterm labour for reducing adverse neonatal outcomes

Babies born too early (preterm birth) are at high risk of poor outcomes, and the earlier they are born the greater their risk. Preterm babies are more likely to die or have serious disability as children, including cerebral palsy and other similar conditions. Women who go into very early labour (before 34 weeks) and have their contractions stopped by intravenous drugs are at high risk of going back into preterm labour. Terbutaline is a drug that can relax the uterus and possibly stop contractions. Taken orally, though, it does not seem to prevent contractions returning. Another option is to use a small portable pump that feeds a continuous dose of terbutaline under the skin. This has the advantage of using a lower daily dose with faster onset of action and good tolerability because of fewer side effects than when taken by mouth. We found four studies involving 234 women who had been in preterm labour and had their contractions stopped. We found no evidence of terbutaline maintenance therapy offering any advantages over saline placebo pump or oral terbutaline maintenance therapy in reducing adverse neonatal outcomes by prolonging pregnancy among women with arrested preterm labour. The review found there are not enough large trials to show whether terbutaline pump maintenance therapy is safe or effective.

Authors' conclusions: 

We found no evidence that terbutaline pump maintenance therapy decreased adverse neonatal outcomes. Taken together with the lack of evidence of benefit, its substantial expense and the lack of information on the safety of the therapy do not support its use in the management of arrested preterm labour. Future use should only be in the context of well-conducted, adequately powered randomised controlled trials.

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Background: 

After successful inhibition of threatened preterm labour women are at high risk of recurrent preterm labour. Terbutaline pump maintenance therapy has been used to reduce adverse neonatal outcomes. This review replaces an earlier Cochrane review, published in 2002, which is no longer being updated by the team.

Objectives: 

To determine the effectiveness of terbutaline pump maintenance therapy after threatened preterm labour in reducing adverse neonatal outcomes.

Search strategy: 

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 January 2014) and reference lists of retrieved studies.

Selection criteria: 

Randomised controlled trials comparing terbutaline pump therapy with alternative therapy, placebo, or no therapy after arrest of threatened preterm labour.

Data collection and analysis: 

Two review authors independently assessed the studies for inclusion and then extracted data as eligible for inclusion in qualitative and quantitative synthesis (meta-analysis).

Main results: 

Four studies were included with a total of 234 women randomised. The overall methodological quality of the included studies was mixed; two studies provided very little information on study methods, there was high sample attrition in one study and in three studies the risk of performance bias was high. We found no strong evidence that terbutaline maintenance therapy offered any advantages over saline placebo or oral terbutaline maintenance therapy in reducing adverse neonatal outcomes by prolonging pregnancy among women with arrested preterm labour. The mean difference (MD) for gestational age at birth was -0.14 weeks (95% confidence interval (CI) -1.66 to 1.38) for terbutaline pump therapy compared with saline placebo pump for two trials combined. One trial reported a risk ratio (RR) of 1.17 (95% CI 0.79 to 1.73) for preterm birth (less than 37 completed weeks) and a RR of 0.97 (95% CI 0.51 to 1.84) of very preterm birth (less than 34 completed weeks) for terbutaline pump compared with saline placebo pump. We found no evidence that terbutaline pump therapy was associated with statistically significant reductions in infant respiratory distress syndrome, or neonatal intensive care unit admission compared with placebo. Compared with oral terbutaline, we found no evidence that pump therapy increased the rate of therapy continuation, or reduced the rate of infant complications or maternal hospital re-admissions. One study suggested that pump therapy resulted in significantly increased weekly cost/woman, $580 versus $12.50 (P < 0.01). No data were reported on long-term infant outcomes.

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