RESUMEN
OBJECTIVES: To determine the effect of labor induction using prostaglandin, gestation period and delivery type on the cause and extent of birth-canal injuries. METHODS: A retrospective study based on the records of II. GPK UNB Ruzinov. The total set (n = 1377) consisted of patients who went into labor in second half of the year 2014 at this clinic. The research used categorical data divided into groups of factors (induction, week of delivery, type of delivery) and birth injuries. Using the chi-square test and Fisher's test we evaluated individual statistical dependences. The results with the highest level of significance are expressed through contingency tests (Phi coefficient, contingency coefficient, Cramer's V). Finally, because of the highest level of significance we have done a cohort study to express the incidence of relationship between non-operative delivery per vaginam and 1st degree ruptura perieni. RESULTS: Labor induction with prostaglandins has a positive impact on the cause and extent of birth-canal injuries, namely the increased risk of vaginal walls tearing and uterine ruptures. We confirmed that the induction of labor using PG carries a demonstrable risk of pregnancy termination by cesarean section (p = 6.17x10-9). Birth-canal injuries are also affected by the type of delivery. Non-operative vaginal delivery is a significant risk factor for first-degree perineal tear (RR = 25.52 95% CI 10.58, 61.60, OR = 33.06 95% CI 13.51, 80.90). Significant risk factors for third-grade perineal tear during vaginal delivery are forceps (p = 0.005534) / vacuum extractor (p = 0.03554). CONCLUSION: In a group of 1377 patients we have demonstrated that the labor induction with prostaglandins, gestation period and type of delivery significantly influence the occurrence and extent of birth-canal injuries (Tab. 3, Ref. 9).