What are uterine fibroids?
Uterine fibroids are growths of tissue that can form within the uterus. Fibroids develop from normal muscle tissue, and are almost always non-cancerous. Many women who have fibroids never even know they have them, because they rarely lead to symptoms. They appear to be caused by estrogen, and usually shrink after a woman enters the menopause. There are different types of uterine fibroids. Some grow within the muscular wall of the uterus, others protrude into the uterus, and yet others actually grow outside of the uterus from its outer wall. And though many women have no symptoms to indicate they may have uterine fibroids, some do. They are not completely harmless, either. Where symptoms do appear, they are most likely to be:
- Very long menstrual periods with heavy bleeding
- Pelvic bloating
- Painful sexual intercourse
Moderate-sized fibroids and large fibroids can often be felt by a doctor during a pelvic exam. Ultrasound and MRI provide a visual confirmation of the presence of uterine fibroids, and a biopsy can check whether the fibroids are cancerous. The possible diagnosis of uterine fibroids is just one reason to see your OBGYN for a preconception checkup if you are planning on trying to conceive in the near future. Fibroids can, in some cases, cause complications during pregnancy. We'll examine that in a minute. If you are going to try for a baby, you may also like to know that uterine fibroids can interfere with the passage of sperm into the uterus, and that they can block the entrance to the fallopian tubes in some cases.
Uterine fibroids and pregnancy complications
Uterine fibroids can reach a diameter of 15 centimeters or even more than that. Most firboids stay the same size throughout your pregnancy, but one third will react to the hormonal changes in your body and grow in size. Fibroids are rarely lone travelers; they often present in clusters. At this rate, you may actually be surprised to hear that fibroids do not usually interfere with pregnancy. But they can, and do in 10 to 30 percent of cases.
Miscarriage is the most likely pregnancy complication with fibroids. Your risk of having repeated early pregnancy losses is significantly higher if you suffer from fibroids. Many doctors do not recommend the removal of uterine fibroids, but suggest that you undergo surgery to remove fibroids if you have suffered multiple miscarriages. Surgery is especially likely to be helpful if the shape of your uterus has been distorted by the presence of fibroids, or if you have fibroids located in the lower part of the uterus. Women who have large fibroids and know about them before they get pregnant may like to discuss surgical options before they attempt to get pregnant and may avoid pregnancy losses by having surgery.
Early pregnancy spotting is another possible complication of fibroids, but only if your fibroids are located close to the spot where your embryo implanted. Complications from fibroids are more often seen in the later stages of pregnancy, however. The most common late-pregnancy complications caused by uterine fibroids are the early rupture of membranes and preterm labor.
Placental abruption, a complication during which the placenta detaches from the uterine wall, is also more common in women with uterine fibroids (a threefold increase in risk).
Several studies also suggest that placenta previa, where the placenta covers the cervix, is much more likely in women with large or numerous uterine fibroids. Finally, labor can be obstructed in women who have fibroids that physically get in the way of delivery, and the baby's presentation can be less than ideal, again because the fibroids can force the baby into a certain position. Though I have not been able to locate a study suggesting that cesarean sections are more common in women with large fibroids, I personally know a woman who had to have a c-section because a large fibroids was preventing her baby from entering the birth canal.
In other words, this can happen. If you have fibroids during pregnancy, it is best to seek out an OBGYN who is experienced in dealing with them, and to make sure that monitoring fibroids is an integral part of your regular prenatal care regime.