Premature labor and indomethacin.

Women in the 29th - 32nd week of gestation were admitted to hospital following the onset of premature labor contractions. After treatment with bed rest and beta-stimulating drugs, those patients with persistent uterine contractions were treated with oral indomethacin (25 mg every 6 hours for 5 days). The effect of indomethacin therapy was monitored by serial external tocometry recordings. This treatment schedule with indomethacin was repeated on several occasions at intervals of 5 to 10 days. Using a standardized technique, uterine contractility was monitored every second or third day throughout the entire treatment period. In this way, the frequency of contractions was evaluated in the presence or absence of indomethacin therapy. Following indomethacin treatment, there was a significant decrease in the frequency of contractions in all cases and a complete arrest of contractions occurred in some women. An increased frequency of contractions was observed during those times that the patient did not receive indomethacin. The plasms concentration of 15-keto-13, 14-dihydro-PGF2alpha, the major serum metabolite of PGF2alpha, was determined by the gas chromatography - mass spectrometry method before and after indomethacin in a limited number of cases. At the doses given for the duration of therapy used, no untoward effects could be detected in either the mother or the infant. These results indicate that indomethacin is a potent and useful drug in the treatment of premature labor.