The effects of ritodrine on experimentally induced intra-uterine growth retardation in the rat.

The effects of oral ritodrine on artificially induced intra-uterine growth retardation in rats were tested in two animal models. In one model, foetal hypotrophy was induced by reduction of the uterine blood supply on ligating of the left uterine artery. In that experiment no significant inhibition of the foetal hypotrophy could be detected in the ritodrine treated animals, but the corresponding reduction of placental weight was inhibited. In the other model, hypotrophy was induced by hypothermia. Oral ritodrine, given twice daily in a dose of 50 mg/kg from day 7 to day 21 of the pregnancy, antagonized the decrease of the foetal weight produced by hypothermia.