A randomized trial of two beta-mimetic drugs for the treatment of threatening early labor

Abstract

Ritodrine (Prepar, Utopar) and fenoterol (Berotec, Partusisten) were tested in a randomized way, and judged in their capacity to lengthen the duration of pregnancy after symptoms of threatening immature — or premature — delivery. Apart from on age, the two groups, each including 48 patients, were comparable on relevant factors as parity, obstetric history, amenorrhea at the start of treatment and tocolytic index. No statistically significant difference was found according to the gain in days, either in absolute number or in relation to the lengthening of pregnancy that could possibly be reached. The outcome of pregnancy, tested by several parameters, was the same for both groups. As to the side-effects, the expected increase in heart frequency during treatment proved to be more pronounced in the ritodrine-treated patients, judged at the maximum dose levels used. However, the evaluation of side-effects has been made between two groups treated with the minimum dose necessary to achieve complete tocolysis, and not in a longitudinal study comparing equivalent doses in each woman.