The prevalence and impact of fibroids and their treatment on the outcome of pregnancy in women with recurrent miscarriage.

BACKGROUND Although uterine fibroids have been associated with spontaneous miscarriage, to our knowledge there have been no studies in the literature assessing their role in the recurrent miscarriage (RM) population. The aims of this study are to examine the impact of different types of fibroids on the pregnancy outcome of women with RM and to investigate to what extent resection of fibroids distorting the uterine cavity affects the outcome of a future pregnancy. METHODS The study analysed retrospective and prospective data from a large tertiary referral RM clinic. Couples were investigated as per an established protocol. Fibroids were diagnosed using combined transvaginal ultrasound and hysterosalpingography. Fibroids distorting the uterine cavity were resected via hysteroscopy. Two study groups were subsequently examined: women with cavity-distorting fibroids who underwent surgery (n =25) and women with fibroids not distorting the cavity who did not undergo any intervention (n =54). The latter was compared with a control group of women with unexplained RM (n =285). RESULTS The prevalence of fibroids was found to be 8.2% (79/966). In total, 264 pregnancies of women with fibroids and 936 pregnancies of women with unexplained RM were analysed. Women with intracavitary distortion and undergoing myomectomy significantly reduced their mid-trimester miscarriage rates in subsequent pregnancies from 21.7 to 0% (P< 0.01). This translated to an increase in the live birth rate from 23.3 to 52.0% (P< 0.05). Women with fibroids not distorting the cavity behaved similarly to women with unexplained RM achieving a 70.4% live birth rate in their subsequent pregnancies without any intervention. CONCLUSIONS Fibroids are associated with increased mid-trimester losses amongst women with RM. Resection of fibroids distorting the uterine cavity can eliminate the mid-trimester losses and double the live birth rate in subsequent pregnancies. Women with fibroids not distorting the uterine cavity can achieve high live birth rates without intervention.