Introduction
Uterine myomas (leiomyomata, fibroids) are the most common tumor of the reproductive tract, with a prevalence of 20–25%1 and a cumulative incidence of 70% in women of reproductive age.2
It has been reported that the presence of fibroids is associated with infertility, spontaneous abortion, fetal malpresentation, placenta previa, preterm birth, cesarean section, and peripartum hemorrhage.3 Although surgical interventions such as myomectomy have been tried in infertile women without specific causes, it is unclear whether the treatment of uterine fibroids can improve pregnancy outcomes, except for cavity-distorting myomas (submucosal, or intramural with a submucosal component).4 The most serious concern in pregnancies after myomectomy is the risk of uterine rupture, which can result in significant increased morbidity and mortality for both the mother and the fetus. The incidence of uterine rupture after prior myomectomy has been reported to range from 0.2 to 3.7% in women with prior myomectomy.5 There is no consensus on the optimal interval between myomectomy and conception.
In US Census Bureau population projections, it was estimated that myomectomies are predicted to increase 31% between 2007 and 2050.6 In Korea, the number of women who underwent myomectomy have increased 37.3% between 2006 and 2010.7 Women in their 30s and 40s, who are a major population for pregnancy, have been major candidates for myomectomy. Because there is insufficient evidence that myomectomy improves pregnancy outcomes, a practice committee of the American Society for Reproductive Medicine (ASRM) reported that myomectomy is generally not advised for improving pregnancy outcomes in asymptomatic women with non-cavity-distorting myomas.8 The Society of Obstetricians and Gynaecologists of Canada (SOGC) also recommended against myomectomy in women with intramural fibroids (hysteroscopically confirmed intact endometrium) and otherwise unexplained infertility, regardless of their size.9
The purpose of this study was to evaluate adverse pregnancy outcomes in women with a history of diagnosed myoma or myomectomy, including prevalence of uterine rupture in women with myomectomy, according to the time interval after myomectomy.