Double blind trial of ritodrine and placebo in twin pregnancy. Effect of prophylactic outpatient administration of fenoterol on the time of onset of spontaneous labor and fetal growth rate in twin pregnancy. Prevention of prematurity in twin pregnancy by orally administered terbutaline. Failure to prevent preterm labour and delivery in twin pregnancy using prophylactic oral salbutamol. Ritodrine HCL for the prevention of premature labor in twin pregnancies. A double-blind trial of oral isoxuprine in the prevention of premature labour.
In a double blind trial, 25 patients with twin pregnancy were given 40 mg of ritodrine hydrochloride by mouth daily and 24 similar patients received a placebo. The ritodrine group had no significant prolongation of pregnancy nor increase in birth weight, and a high incidence of side effects occurred. A double-blind trial was conducted on outpatients with twin gestations to assess the effect of prophylactic administration of fenoterol on the fetal growth rate and the timing of the spontaneous onset of labor. No significant differences could be shown between the fenoterol-treated group of patients and the control group given a placebo. It is concluded that prophylactic administration of fenoterol does not have a significant effect upon the incidence of preterm labor or growth retardation in twin pregnancy. The intention of this study was to evaluate whether perorally administrated terbutaline given prophylactically could reduce prematurity in twin pregnancy. In a double-blind study, 50 women with twin pregnancies were given either placebo (25) or terbutaline (25). Six in the terbutaline group and 15 in the placebo group went into preterm labor which required intravenous infusion of terbutaline. The difference is statistically significant (p = 0.010). The total number of days in hospital due to preterm labor was 115 in the terbutaline group and 256 in the placebo group. There is a slight difference in prematurity (delivery week less than 37th week) - the placebo group gave birth somewhat earlier - but this difference is not statistically significant. When evaluating this, it has to be considered that 15 of the 25 in the placebo group received parenteral treatment with terbutaline because of preterm labor. Birth weights of the twins in relation to gestational age seemed to be the same in the two groups. A double blind, controlled study was performed to see whether the use of prophylactic oral salbutamol would reduce the incidence of preterm labour in twin pregnancy. Of the 144 women studied, 74 took salbutamol and 70 placebo. No difference was found in the length of gestation, birthweight or fetal outcome, although fewer babies suffered from respiratory distress syndrome in the salbutamol group. Women did not experience troublesome side-effects from salbutamol. The perinatal mortality rate for twin gestation is in the range of 15%, and this is due predominantly to prematurity, although twins may also be born growth retarded. Ritodrine HCl, a beta sympathomimetic drug, has been shown to be effective, both in stopping premature labor and in preventing intrauterine growth retardation. With this in mind, a double-blind study using ritodrine HCl or placebo was begun in order to study its effect on premature labor, intrauterine growth retardation, and the perinatal mortality rate in twins. Thus far, 30 patients have delivered and have been followed to 6 weeks postpartum. Although the results on individual patients have remained blinded to the investigators, an initial evaluation of the ritodrine and placebo groups have revealed no difference with respect to gestational age, birth weight, or perinatal mortality. These preliminary results are not significant. However, it appears that ritodrine HCl is a safe oral agent for the antepartum gravida and her fetus. The study will be continued until approximately 100 patients have been enrolled. nan
There is insufficient evidence to support or refute the use of prophylactic oral betamimetics for preventing preterm birth in women with a twin pregnancy.