A pregnant woman with fibroid uterus develops acute pain in abdomen with low grade fever and mild leucocytosis at 28 weeks. The most likely diagnosis is?

Most are asymptomatic; however, severe localized abdominal pain can occur if a fibroid undergoes so-called “red degeneration,” torsion, or impaction. Pain is the most common complication of fibroids in pregnancy, and is seen most often in women withfibroids > 5 cm during the second and third trimesters of pregnancy.