Uterine fibroids and uterine fibroids during pregnancy

1. What are uterine fibroids?

Uterine fibroids are benign tumors formed by the proliferation of uterine smooth muscle tissue and are the most common benign tumors in women. The incidence of uterine fibroids is difficult to accurately calculate, but it is estimated that the incidence rate in women of childbearing age may reach 25%, and according to autopsy statistics, the incidence rate may reach more than 50%.

2. Causes and pathogenesis?

The exact cause is still unknown. High-risk factors include age > 40 years, young age at menarche, nulliparity, late childbearing, obesity, polycystic ovary syndrome, hormone replacement therapy, black race, and family history of uterine fibroids. These factors are closely related to the increased risk of uterine fibroids. The pathogenesis of uterine fibroids may be related to genetic susceptibility, sex hormone levels, and stem cell dysfunction.

3. Clinical manifestations

1. Symptoms: There may be no obvious symptoms. The patient's symptoms are closely related to the location, growth rate and degeneration of the fibroids. Menstruation may be manifested as increased menstruation, prolonged menstruation, spotting and shortened menstrual cycle. Secondary anemia may occur. There may also be increased vaginal secretions or vaginal discharge. When the fibroids are large, an abdominal mass may be palpated, which is more obvious when the bladder is full in the morning. When the fibroids are large, they may also compress the bladder, rectum or ureter, causing corresponding compression symptoms. Submucosal fibroids can cause dysmenorrhea, and torsion of the pedicles of subserosal fibroids may cause acute abdominal pain. Abdominal pain accompanied by fever may occur when the fibroids are red and degenerated. Uterine fibroids can affect the morphology of the uterine cavity, block the opening of the fallopian tubes, or compress the fallopian tubes to twist and deform them, which may all lead to infertility.

2. Physical signs: The uterus is enlarged, spherical or irregular, or a mass connected to the uterus; it is related to the size, location and number of the fibroids. Submucosal fibroids can prolapse from the cervical opening into the vagina. Subserosal fibroids can be easily misdiagnosed as solid ovarian tumors during physical examination.

4. Diagnosis

1. Clinical symptoms and signs:

The diagnosis can be made based on the aforementioned clinical symptoms or signs.

2. Imaging examination:

The imaging diagnostic methods for uterine fibroids mainly include ultrasound and MRI examinations, and CT examinations are occasionally used. Ultrasound examination is a common method for diagnosing uterine fibroids, with high sensitivity and specificity; however, there are still certain errors in the accurate positioning and counting of multiple small fibroids (such as those with a diameter of less than 0.5 cm). MRI examination can detect fibroids with a diameter of 0.3 cm, and can accurately identify the size, number and location of fibroids. It is an important supplement to ultrasound examination; however, it is expensive, and if an intrauterine contraceptive device is present, it will affect the diagnosis of submucosal fibroids. CT has relatively poor resolution for soft tissues, and slightly poor specificity for the size, number and location of fibroids. It is generally not used for routine examinations of uterine fibroids, but it can show the presence of enlarged lymph nodes and tumor metastasis.

5. Treatment Methods

1. Surgical treatment:

(1) Indications for surgery:

l Uterine fibroids combined with menorrhagia and abnormal bleeding may even lead to anemia or compression of the urinary system, digestive system, nervous system, etc., resulting in related symptoms, and drug treatment is ineffective;

l Uterine fibroids combined with infertility;

l When patients with uterine fibroids are preparing for pregnancy, if the diameter of the fibroid is ≥4cm, it is recommended to remove it;

l Fibroids continue to grow after menopause without hormone replacement therapy;

(2) Contraindications to surgery: (Contraindications vary depending on the surgical method and surgical approach.)

l Acute stage of genital tract or systemic infection;

l Severe medical diseases such as acute stage of heart, liver and kidney failure;

l Severe coagulation disorders and blood diseases;

l There are other conditions that cannot tolerate anesthesia and surgery;

l Laparoscopy is contraindicated in patients with diaphragmatic hernia;

l Uterine fibroids grow rapidly and imaging suggests that they have a malignant tendency. They are not suitable for myomectomy.

2. Drug treatment:

(1) Indications:

l Those who are unwilling to undergo surgery due to uterine fibroids causing menorrhagia, anemia and compression symptoms;

l Pretreatment before myomectomy or hysterectomy to correct anemia, reduce the size of myoma and uterus, and prepare for surgical treatment;

l Patients with uterine fibroids can use drugs to reduce the size of the uterus and fibroids before pregnancy to prepare for pregnancy;

l After multiple uterine myoma removal surgery, prevent the recent recurrence of myoma;

l Those with contraindications to surgical treatment;

(2) Contraindications:

l The fibroids grow rapidly or undergo degeneration, and malignant transformation cannot be ruled out;

l When there is abnormal uterine bleeding, endometrial lesions must be excluded, and hysteroscopy and curettage should be performed if necessary;

l If subserosal fibroids are suspected to have pedicle torsion, surgical treatment should be performed;

(3) Treatment drugs:

Drugs for the treatment of uterine fibroids can be divided into two categories: one category can only improve the symptoms of menorrhagia but cannot reduce the size of fibroids, such as hormonal contraceptives, tranexamic acid, nonsteroidal anti-inflammatory drugs (NSAIDs), etc. The other category can both improve anemia symptoms and reduce the size of fibroids, such as gonadotropin-releasing hormone agonists (GnRH-a) and mifepristone.

6. Pregnancy with uterine fibroids

1. If uterine fibroids occur during pregnancy, can surgical treatment be performed? If the indications for uterine fibroid surgery during pregnancy are met, surgical treatment can be performed. However, the surgery should be performed before 24 weeks of pregnancy, and whether to terminate the pregnancy should be decided based on the condition of the pregnant woman and the fetus.

3. Delivery method for pregnancy complicated with uterine fibroids: It should be determined according to the size and location of the fibroids and the condition of the mother and child. If the uterine fibroids are small and do not affect the progress of labor, vaginal delivery can be chosen. If the uterine fibroids are located in the lower uterine segment, cervix, etc., affecting the connection of the fetal presenting part and the human pelvis, hindering the descent and delivery of the fetus, a cesarean section should be performed electively after full term. There is still controversy about whether to perform uterine fibroid removal during cesarean section. It should be determined according to the size and location of the fibroids, the condition of the pregnant woman, the technical proficiency of the surgeon, and the blood transfusion emergency conditions of the hospital. For fibroids with a diameter of >8 cm, multiple fibroids, fibroids that are not easy to expose (such as submucosal fibroids in the lower uterine segment, cervical fibroids), and large fibroids close to the uterine artery and vein and the interstitial part of the fallopian tube, they should be treated with caution. For critically ill pregnant women, it is not recommended to perform uterine fibroid removal at the same time as cesarean section.

Expert Profile: Wang Wenling, attending physician of obstetrics and gynecology, has been working in obstetrics and gynecology for more than 30 years. She has rich clinical experience in the diagnosis and treatment of common, frequently occurring and difficult diseases in obstetrics and gynecology, perioperative treatment of gynecological tumors, high-risk obstetric pregnancies and critically ill patients. She is good at gynecological inflammation, cervical diseases, infertility, irregular menstruation, uterine fibroids, polycystic ovary syndrome, etc.