['To evaluate the effect of epidural and pethidine analgesia on the frequency of uterine contractions during the first stage of labor.', 'Retrospective study.', 'Delivery ward of a public hospital.', 'Forty consecutive parturients.', 'The mean number of contractions in the 30 min before administration of pethidine analgesia was 8.2+/-1.7 as compared to 8.7+/-1.3 after administration of the analgesia. The mean number of contractions in the 30 min before administration of epidural analgesia was 8.0+/-1.4 as compared to 8.8+/-1.9 after administration of the analgesia. The differences between the two groups and between the number of contractions before and after the administration of both types of analgesia were not statistically significant.'] Is epidural analgesia for labor pain associated with a decreased frequency of uterine activity?