If a fibroid is pregnant, there are, in fact, most of the time no visible symptoms. However, fibroids will almost always grow. Fibroids are affected by estrogen and progesterone, and when pregnant, the levels of these hormones are very high, and the fibroids get enough nutrients, some of them will grow violently, to more than 10 centimeters in diameter, or even bigger, and the volume of fibroids grows according to the third power of the diameter, so you can imagine how much nutrients are needed at this time, which may cause anemia in pregnant women and growth retardation in the fetus. A growing myoma may affect the fetal position, causing malposition such as breech and transverse position; it may also affect the shape of the uterine cavity, leading to miscarriage and premature delivery; if it presses on the sigmoid colon, it may aggravate constipation during pregnancy; if it presses on the bladder, the feeling of frequent and incomplete urination is serious. If the fibroid grows too aggressively, it is prone to red degeneration and abdominal pain. Clinically, there is no too good solution for red degeneration of leiomyosarcoma, and conservative treatment with antibacterial drugs can be considered; if there is an aura of miscarriage or preterm labor, birth control drugs can be used. Most of them can be relieved, but a few severe ones may not be able to keep the fetus.