Urinary trypsin inhibitor: a new drug to treat preterm labor: a comparative study with ritodrine

Prevention of preterm delivery is one of the difficult problems facing obstetricians. beta Adrenergic agonists, especially ritodrine, are commonly used in these cases.

The aim of this research was to study and compare the effect of urinary trypsin inhibitor (UTI) which has anti-inflammatory anti-cytokine effects with ritodrine in treating preterm labor.

Patients in preterm delivery were randomly selected to be treated either by ritodrine or UTI. In the ritodrine group, uterine contractions were initially suppressed by high doses of ritodrine (up to 300 micrograms/min) and then a maintenance dose was given until 35 weeks of gestation. In the UTI group one vaginal suppository (5000 U) was used daily for 2 weeks. Patients with recurrent preterm uterine contraction during the initial 14 days of treatment, who needed course of other drugs to suppress the contractions, were excluded from the study. Patients responding to the drugs were followed until delivery. Tocolytic index and elastase concentration in the cervical mucus was calculated. Recurrence rate of uterine contraction and time of elongation of pregnancy since the beginning of treatment was calculated.

UTI was more effective than ritodrine in inhibition of recurrent uterine contraction and elongation of pregnancy. No side effects could be observed after treatment with UTI for the mother or the fetus.

UTI may be a new therapeutic method for the inhibition of preterm delivery through suppression of cytokines and inflammatory mediators.