Pregnancy with fibroids is more dangerous throughout the pregnancy, but the most dangerous is usually the first trimester of pregnancy. Fibroids are a common gynecological condition, most of them are benign and malignancy is less common. The first trimester is a critical period for fetal organ formation, and pregnant women with fibroids are at higher risk of miscarriage than the average pregnant woman. When the fertilized egg happens to be implanted on the surface of the submucosal fibroid, the endometrium is relatively thin and the embryo does not absorb enough nutrients, which may affect the normal growth and development of the fetus, thus leading to miscarriage. In addition, in the middle and late stages of pregnancy, fibroids growing in the lower part of the uterus may cause obstruction of the birth canal and affect the process of delivery, which may lead to signs of preterm labor during this period. Therefore, it is recommended that pregnant women with fibroids undergo strict and regular maternity checkups, be monitored and protected under the guidance of a doctor, and be given antirefetal treatment if necessary.