Introduction: There is concern about the risk of uterine rupture in the subsequent pregnancy after myomectomy. This risk is reported in literature to be around 0.7-1%. The aim of this study was to evaluate the incidence of uterine rupture and associated risk factors in women who had a trial of labor after prior myomectomy.
Material and methods: A systematic review of the literature was performed including all cohort studies with at least five cases reporting outcomes of pregnancies after prior myomectomy. The terms "myomectomy", "pregnancy", "trial of labor" and "uterine rupture" were used in PubMed and EMBASE searches for identification purposes. Every reference was reviewed for possible inclusion and all eligible cases of uterine rupture were considered.
Results: Twenty-three studies with at least five cases of pregnancy after myomectomy were identified, with an overall incidence of uterine rupture of 0.6% (0.3-1.1%) (n = 11/1825). Of these 23 studies, 11 studies reported detailed data about trial of labor after myomectomy and related pregnancy outcomes, including 1034 pregnancies and 756 viable (≥24 weeks) deliveries. The overall incidence of uterine rupture after myomectomy in the included studies was 0.93% (0.45-1.92%) (n = 7/756); specifically, it was 0.47% (0.13-1.70%) (n = 2/426) in women undergoing trial of labor after myomectomy, and 1.52% (0.65-3.51%) (n = 5/330) in women before the onset of labor. Of the seven uterine ruptures, five (71%) occurred within 36 weeks (range 24-40 weeks).
Conclusions: Trial of labor after myomectomy is associated with a 0.47% risk of uterine rupture. There were no identified risk factors among the variables studied. The present systematic review of the literature revealed that uterine rupture after prior myomectomy occurred mainly before 36 weeks and before labor.
Keywords: Myomectomy; pregnancy; trial of labor; uterine rupture; uterine scar.
© 2016 Nordic Federation of Societies of Obstetrics and Gynecology.