Uterine fibroids are common benign tumors in women of reproductive age, with an incidence of 20-30%, while pregnancy combined with uterine fibroids is a common high-risk factor in obstetrics, with an incidence of 0.1%-3.9%. In China, the incidence of fibroids is increasing with the emergence of late marriages and advanced maternal age. Since fibroids can affect patients in all periods of childbirth, pregnancy, delivery and puerperium, the proper management will have a bearing on the health of mother and child. 1, the impact of pregnancy on uterine fibroids: uterine fibroids are estrogen-dependent benign tumors, and it is generally believed that due to the continuous rise of estrogen and progesterone during pregnancy, fibroids will increase accordingly. However, it is still controversial whether uterine fibroids increase in pregnancy. Foreign scholars have used ultrasound to monitor the development of fibroids (<5 cm) in a group of 113 patients with pregnancy-associated fibroids and found that the fibroids were enlarged in the early and middle stages of pregnancy, while they were found to be smaller or quiescent in the late stages of pregnancy, while some scholars have found the opposite. In conclusion, the effect of pregnancy on fibroids varies from person to person, and its mechanism needs to be further elucidated by systematic research. It is generally believed that the presence of fibroids increases the size of the uterus, distorts the shape of the uterine cavity, induces dysfunctional contraction of the uterus, changes the distribution of blood vessels in the uterine body, and induces inflammation and abnormal secretion of the endometrium. This disrupts the microenvironmental balance of the endometrium, and these factors together affect the transport of sperm and eggs, hinder the implantation of congeners and the invasion of villi, and as a result lead to infertility. Confined to submucosal fibroids and giant fibroids that affect the structure of the uterine cavity line, fibroids are one of the causes of infertility, but not the main cause. 3, the effect of fibroids on pregnancy: the effect of fibroids on pregnancy varies with the size and location of fibroids and different periods of pregnancy. In the early and middle stages of pregnancy, vaginal bleeding and spontaneous miscarriage are likely to occur; in the late stages of pregnancy, preterm labor, placental abruption, intrauterine growth retardation and fetal compression syndrome are likely to occur; during delivery, fetal malposition, obstructed labor, rupture of scarred uterus and postpartum hemorrhage and retained placenta after delivery. The diagnosis of pregnancy-associated uterine fibroids: pregnancy-associated uterine fibroids usually have no obvious clinical symptoms, and the physical signs may show raised fibroids on the uterine wall or no manifestation at all. In order to improve the diagnosis of uterine fibroids in pregnancy, it is necessary to strengthen the pre-pregnancy, early and mid-pregnancy education and examination. The treatment of pregnancy-associated fibroids: pregnancy-associated fibroids generally have no obvious clinical manifestations throughout pregnancy. The domestic tendency is to carry out expectant therapy and conservative treatment during pregnancy. If the following conditions occur: ①, rapid progressive enlargement of fibroids leading to discomfort; ②, abdominal pain that is ineffective by traditional conservative treatment; ③, ensuring that the lowest layer of fibroids is >5 mm from the uterine cavity; ④, preferably at 15-19 weeks of gestation; ⑤, informed consent and signature of the patient and family for the condition, surgery is advocated, and the surgical procedure is transabdominal myomectomy. Regarding the choice of delivery method, the rate of spontaneous vaginal delivery in foreign countries with myomas <10 cm was not significantly different from that of normal pregnant women, whereas in China, vaginal delivery was advocated only for individual myomas <3 cm or even 2 cm, and the rest were performed by cesarean section with intraoperative myomectomy. Myomectomy at cesarean delivery is a controversial and hot issue. The opposing side believes that the enlarged pregnant uterus is richly vascularized, which makes it easy to bleed during surgery, and that the softness of the fibroids and the surrounding area are not clearly defined, which makes the surgery more difficult; in addition, there is a possibility that the fibroids will shrink after delivery. In contrast, the positive side believes that the difficulty of myomectomy during cesarean section is not significantly increased, and intraoperative bleeding is not significantly increased, while the removal of myoma helps to eliminate the blood in the uterine cavity and restore the uterus, and reduces the chance of puerperal infection and reoperation.