Uterine fibroids, also known as leiomyomas, are non-cancerous growths composed of muscle cells that develop within the wall of the uterus. They are common in women of reproductive age and are often discovered incidentally during a pregnancy ultrasound. While most pregnancies proceed without issue, fibroids can cause worry, particularly when accompanied by spotting or bleeding. Fibroids can contribute to vaginal bleeding during gestation, which warrants prompt medical evaluation.
How Fibroids Cause Spotting During Pregnancy
Fibroids can disrupt the uterine environment, leading to spotting, especially during the first and second trimesters. A frequent cause of pain and bleeding is red degeneration, or aseptic necrosis. This occurs when the rapidly growing fibroid outgrows its limited blood supply, often encouraged by the surge of pregnancy hormones.
The resulting lack of oxygen and tissue death within the fibroid can cause severe localized pain and associated bleeding as the area becomes inflamed. Fibroids larger than five centimeters are more likely to undergo this degeneration. Symptoms can usually be managed conservatively.
Another mechanism relates to the fibroid’s location relative to the placenta and the uterine cavity. Submucosal fibroids, which bulge into the inner uterine space, are prone to interfering with the integrity of the endometrial lining.
If a fibroid is situated near the site where the placenta implants, it can interfere with the connection between the placenta and the uterine wall. This localized interference with placentation can result in bleeding. This bleeding is more common when the placenta is close to the fibroid.
Other Pregnancy Complications Linked to Fibroids
Fibroids can be associated with several other complications that may affect the pregnancy timeline or delivery method. Large fibroids or those undergoing degeneration can cause significant uterine irritation, which may increase the likelihood of contractions. This increased uterine activity contributes to a higher risk of preterm labor and delivery before the 37th week of gestation.
The physical presence of a fibroid can also interfere with the placenta’s normal position and attachment. If a fibroid is located close to the placenta, there is an increased risk of placental abruption, a serious condition where the placenta prematurely separates from the uterine wall. Fibroids can also increase the risk of placenta previa, where the placenta covers the cervix, often associated with late-pregnancy bleeding.
In rare instances, very large or numerous fibroids may restrict the space available for the developing fetus, contributing to fetal growth restriction. The size and location of fibroids are significant factors in determining the mode of delivery.
Fibroids located low in the uterus, especially near the cervix, can physically obstruct the birth canal. This prevents the baby from moving into the correct position for a vaginal birth. This obstruction, along with a higher incidence of abnormal fetal presentation, increases the likelihood that a planned Cesarean delivery will be necessary.
Monitoring and Managing Fibroids During Gestation
Once fibroids are identified, the medical approach during pregnancy focuses on careful monitoring and symptom management. Regular ultrasound examinations are the standard tool used to track the fibroid’s size, assess its location relative to the placenta, and check on the fetus’s overall well-being.
If a fibroid causes pain, management strategies are conservative and involve rest, increased fluid intake, and the use of appropriate pain relievers. Acetaminophen is the preferred analgesic for managing discomfort and is considered safe throughout all trimesters of pregnancy.
Surgical removal of fibroids (myomectomy) is rarely performed during pregnancy due to the elevated risks of significant bleeding and pregnancy loss. Nonsteroidal anti-inflammatory drugs (NSAIDs) may be used for short periods to manage severe pain from degeneration. However, their use is generally avoided, particularly after 32 weeks of gestation, due to potential fetal risks.
The symptoms of pain and bleeding related to fibroid degeneration often resolve on their own within a few days to a week with conservative management. If severe, persistent pain does not respond to oral medication, a brief hospital stay for observation and more potent pain relief may be required.
Warning Signs Requiring Immediate Medical Attention
While mild spotting and manageable pain are sometimes expected with fibroids, certain signs indicate a potential emergency requiring immediate consultation with a healthcare provider. Any instance of vaginal bleeding during pregnancy should prompt a call to your doctor, especially if the bleeding becomes heavy.
Heavy bleeding is defined as soaking through one sanitary pad or more within an hour, or the passage of large blood clots. A medical evaluation is necessary if you experience sudden, severe, and unrelenting abdominal pain that is not relieved by rest or prescribed pain medication.
Other urgent warning signs include fever, dizziness, or fainting, which can be signs of significant blood loss or a systemic issue. Even if fibroids are the known source of discomfort, these extreme symptoms could indicate a complication like placental abruption or another serious event and should never be ignored.