Because uterine fibroids are estrogen-dependent tumors that accompany women of childbearing age, the relationship between them and pregnancy and childbirth is complex and entangled. Is it left or right, front or back? Standing at the crossroads of life, it may be beneficial to know more about the secrets of the body in order to break through and gain a new life. With the development of medicine, there are fewer and fewer tragedies in which uterus is removed when fibroids are present, thus completely losing the reproductive function. However, because fibroids are estrogen-dependent tumors that accompany women of childbearing age, the relationship between them and pregnancy and childbirth is complex and entangled. In early pregnancy, the presence of fibroids is detrimental to the implantation and growth of a fertilized egg, and the incidence of miscarriage is two to three times higher than that of a normal woman without fibroids. Large interstitial myomas or submucosal myomas can prevent the fetus from moving around in the uterine cavity and cause malposition. Myomas can affect the normal contraction of the uterus and prolong labor. Large myomas embedded in the pelvic cavity can block the birth canal and cause obstructed labor. Myomas can also affect the contraction of the uterus after delivery, causing postpartum hemorrhage. On the other hand, the smooth muscle cells of the uterus increase in size after pregnancy, and thus the fibroids also increase in size, most significantly in the first 4 months of pregnancy. Rapidly enlarging fibroids are prone to inadequate blood supply and degenerative changes, most often in the form of red lesions. Patients develop fever, abdominal pain, vomiting, localized pressure, and even cause miscarriage and preterm labor. As we can see, the relationship between uterine fibroids and pregnancy and childbirth is really cut and dried. However, we can still try to sort it out from the following aspects. What should I do if I am going to get pregnant and a fibroid is found? Generally speaking, if the relationship with pregnancy and childbirth is not considered, only those fibroids that are in an unusual location (described later), have symptoms such as heavy menstruation, incomplete menstruation, anemia, or are more than 5 cm in diameter need surgery. In the case of women who are preparing to become pregnant, the indications for treatment should be appropriately wide. In the case of submucosal fibroids located in the uterine cavity, there is a risk of miscarriage due to the possibility of preventing the future embryo from being laid. Therefore, regardless of the presence or absence of symptoms (usually excessive menstruation or dripping menstruation), treatment is recommended before pregnancy. It is currently considered that submucosal fibroids are best operated through hysteroscopy. Hysteroscopy is also a type of minimally invasive surgery, which involves placing a special camera lens through the vagina and cervical canal and performing the procedure with special instruments. So, how big is a fibroid that must be operated on before pregnancy? There is no clear standard. Some medical units (e.g. Peking Union Medical College Hospital) believe that patients can consider pregnancy if the fibroids do not exceed 4 cm in diameter for interstitial fibroids or subplasma fibroids. However, patients need to be informed that the fibroids may grow rapidly during pregnancy and cause red degeneration due to ischemia, or that the subplasmalemma may twist when the uterus changes position, which may cause miscarriage or premature delivery. If the fibroid is located at the lower end of the uterus, i.e., the cervix, or other parts of the uterus where the fibroid is less than 4 cm in diameter, but the patient has a history of infertility or multiple spontaneous miscarriages and no other definite cause can be found, fibroid removal may also be performed first and then pregnancy. Assuming that the fibroids are removed before pregnancy, how long do I have to use contraception after surgery before I can get pregnant? This is a question that cannot be answered preoperatively and needs to be determined intraoperatively. In general, if the fibroids are located between the muscle walls or under the plasma membrane, the number is small, the integrity of the uterine wall is not significantly damaged during the removal process, and they do not enter the uterine cavity, pregnancy is possible after 6 months of postoperative contraception; if the number of fibroids is large, many incisions are made in the uterus, the removal process is particularly difficult, or they enter the uterine cavity, then contraception is recommended for at least one year, or even two years. Of course, in the case of subplasmic fibroids with a slender tip attached to the uterus, if the operation went well and little damage was done to the integrity of the uterine wall, pregnancy is possible after 3 months of postoperative contraception.