Uterine fibroids are often found in pregnant women with the estimated prevalence of 1.4-3.9%. The most common complaint of uterine fibroids during pregnancy is acute abdominal pain. Acute pain due to uterine fibroids degenerating is severe to require hospitalization for pain relief. In the current study, we aimed to elucidate the risk factors for fibroid-related abdominal pain during pregnancy. We conducted a retrospective cohort study on 109 pregnant women with uterine fibroids delivered at Kyorin University Hospital between April 2015 and June 2019. We reviewed the maternal backgrounds(age, body mass index, parity, history of myomectomy, gestational age, preterm birth rate, birth weight), the fibroids characteristics(size, number, type) and the treatment(medication, hospitalization or not). Among group 1(no symptoms, N=70), group 2(oral medication only, N=24)and group 3(hospitalization, N=15), there was significant difference in the frequency size and type of uterine fibroids. Increasing size of uterine fibroids and subserosal uterine fibroids were associated with higher rates of admissions for fibroid-related pain. In addition, we detected subserosal uterine fibroids were an independent risk factor of fibroid-related pain during pregnancy by the multivariate analysis.