RESUMEN
OBJECTIVE: To appraise the relationship between the length of exposure to epidural analgesia and the risk of non-spontaneous birth, and to identify additional risk factors. This study is framed within the MidconBirth project. STUDY DESIGN: A multicentre prospective study was conducted between July 2016 and November 2017 in three maternity hospitals in different Spanish regions. The independent variable of the study was the length of exposure to epidural analgesia, and the dependent variable was the type of birth in women with uncomplicated pregnancies. The data was analyzed separately by parity. A multivariate logistic regression was performed. The odds ratios (OR), using 95% confidence intervals (CI) were constructed. MAIN OUTCOME MEASURES: During the study period, 807 eligible women gave birth. Non-spontaneous births occurred in 29.37% of the sample, and 75.59% received oxytocin for augmentation of labour. The mean exposure length to epidural analgesia when non-spontaneous birth happened was 8.05 for primiparous and 6.32 for multiparous women (5.98 and 3.37 in spontaneous birth, respectively). A logistic regression showed the length of exposure to epidural during labour was the major predictor for non-spontaneous births in primiparous and multiparous women followed by use of oxytocin (multiparous group). CONCLUSIONS: The length of exposure to epidural analgesia during labour is associated with non-spontaneous births in our study. It highlights the need for practice change through the development of clinical guidelines, training programs for professionals and the continuity of midwifery care in order to support women to cope with labour pain using less invasive forms of analgesia. Women also need to be provided with evidence-based information.