With a great number of women diagnosed with fibroids in their childbearing age, many wonder how do fibroids evolve during pregnancy? What complications do they cause to the pregnancy? And what fibroid treatment does not compromise fertility? Today we are going to cover these questions and provide you with the latest data on fibroids development during the first, the second, and the third trimesters.
Uterine fibroids are benign tumors that grow in and around the uterus. They can range in size from a small pea to a pumpkin with the largest fibroid ever reported in a living person weighing over 100 pounds! It is estimated that 80% of women have fibroids by the time they are 50 years old. Some women who have fibroids do not ever experience symptoms, while others have symptoms that completely turn their lives upside down.


Identifying Fibroids During Pregnancy
A Magnetic Resonance Imaging (MRI) test has the highest resolution of the imaging modalities available but is rarely used in pregnant women with fibroids. There are no proven risks to pregnant women or unborn babies from MRI exams. Over the last 30 years, thousands of pregnant women have had MRI exams, and no known harmful effects to the baby have been found. MRI’s role is one of problem-solving for cases that ultrasound does not provide an answer.
Transabdominal and transvaginal ultrasound is the most common imaging tool used in pregnant patients with or without fibroids. Because fibroids are harder to detect during pregnancy, experts agree that the actual number of cases is under-reported.
Complications During Pregnancy Caused By Fibroids
Many women who have fibroids will not have any issues during pregnancy. For others, fibroids can cause challenges such as fetal demise, miscarriage, abnormal placental position, postpartum hemorrhage, breech birth, preterm labor, or the need for a C-section.
First Trimester Challenges With Fibroids
Not all fibroids grow during pregnancy but studies have shown that approximately 1/3 of existing fibroids are affected and, in most cases, the growth was contained to the first trimester. The study reported that the fibroids that did grow increased in volume an average of 25%, and it occurred in both small and large fibroids.
Fibroid growth is directly related to the presence of the hormone estrogen, and during the first trimester of pregnancy estrogen levels are elevated significantly. Also, fibroids need a blood supply to grow and during the first trimester, a woman’s blood volume increases. An additional study reported that women who were pregnant with baby girls experienced increased fibroid growth into the second trimester compared to those expecting boys.
Fibroids that grow during pregnancy can cause issues such as:
- Bleeding – the fibroid’s location is what determines the risk for bleeding during early pregnancy. Fibroids increase the risk for placenta previa and placental abruption. Placenta previa is a condition where the placenta implants across the cervix. Placental abruption is the premature separation of the placenta from the uterus. A very important part of the ultrasound exam of the pregnant patient is to evaluate the placenta. While a number of women early in pregnancy may have a placenta previa, the vast majority of these cases resolve as the fetus and uterus enlarge during the pregnancy resulting in the placenta moving away from covering the cervix.
- Pain – abdominal cramping and pain are the most common symptoms caused by fibroids during pregnancy. Research shows that approximately 59% of women with fibroids experience pain during their pregnancy and 30% experienced both pain and bleeding. Pain may be present in the abdomen, pelvis, lower back, buttocks, legs, and/or hips.
- Miscarriage – statistics show that women who have fibroids are at greater risk for spontaneous miscarriage than those without fibroids – approximately 14% vs. 7%. The size of the fibroid did not seem to affect the rate of miscarriage, but multiple fibroids did increase the risk. Miscarriages were more prevalent in women with intramural and submucosal fibroids. Experts do not know exactly how fibroids prompt miscarriages. Studies have identified decreased blood supply to the growing placenta and fetus and increased uterine contractions caused by fibroids as potential causes.

Second And Third Trimester Challenges With Fibroids
As pregnancy progresses and the baby is growing, the uterus expands and can start pushing against fibroids causing pain and other more serious issues. For most women studied, fibroids stayed the same size after the second trimester or even shrunk during the third trimester. Even so, fibroids that are present during pregnancy and delivery can cause serious issues.
Pain is one of the most reported symptoms of fibroids during the latter part of pregnancy:
- As the pregnancy progresses, large fibroids, that may have grown even larger during the first trimester, can push on and crowd other internal organs.
- Fibroids located on the back of the uterus can put pressure on the spinal column and cause back or leg pain, much like sciatica.
- On rare occasions, a fibroid can suddenly twist, which is known as fibroid torsion and is considered a medical emergency causing sharp pain or cramping.
- Degeneration is another severe complication that may happen in late pregnancy. This is a condition that generally occurs in fibroids that are over 5 cm. They have outgrown their blood supply causing them to degenerate and release prostaglandins – the same substance that causes contractions during labor – at dangerous levels, which may result in spontaneous miscarriage.
Placental abruption – cumulative clinical data show that pregnant women with large fibroids growing behind or between the uterine wall and the placenta are three times as likely to experience a rupture of the placenta. The placenta tears away from the uterine wall and inhibits the oxygen flow to the baby as well as causing heavy bleeding which can be fatal to both mother and fetus.
Early delivery – a woman with fibroids is 16% more likely to experience preterm labor. Researchers believe this to be a result of multiple fibroids or fibroids that are in contact with the placenta.
Video: Fibroids and Pregnancy
Delivery And Postpartum With Fibroids
Many studies have shown that complications during delivery can arise as a result of fibroids.
Breech births are 13% more likely and can be caused by large fibroids located in the lower part of the uterus, or if there are multiple fibroids present.
Cesarean section (C-section) – 48.8% of women with fibroids deliver via C-section due in part to the increased risk of dystocia – slow or protracted labor, which is twice as likely in pregnant women with fibroids. Fibroids can also block the birth canal which can also necessitate a c-section.
Postpartum hemorrhage – women with fibroids have an increased risk of postpartum hemorrhage also called PPH. PPH occurs in 2.5% of women with fibroids and presents as heavy bleeding after delivery. It can happen within the first 24 hours and up to 12 weeks after giving birth. Interventional radiologists can perform a procedure very similar to Uterine Fibroid Embolization (UFE) in an emergency setting for postpartum hemorrhage. The wife of legendary professional golfer Phil Mickelson was saved by this procedure following the birth of their third child.
Placenta retention – it is considered a medical emergency when the placenta is not delivered within ½ hour after the baby during vaginal birth. One source reported that fibroids located in the lower portion of the uterus resulted in a higher instance of placenta retention. When comparing all data available, regardless of the location of the fibroids, 1.4% of women with fibroids experienced placenta retention.
UFE Treats Fibroids Without Risks for Future Pregnancy
For about 50% of women, fibroid symptoms lessen after giving birth. But for others, their symptoms can become worse. The only way to eliminate fibroid symptoms is to get rid of all fibroids. With the UFE procedure, it can be done effectively prior to or after pregnancy with no risks for future ones.
Uterine Fibroid Embolization (UFE) is a non-surgical, outpatient procedure that treats symptomatic fibroids. Recovery after UFE is typically 5-7 days. 90% of women report significant improvement in their menstrual cycle within 3 months, many on the very first one. In 3 months they can also start trying to conceive.
Numerous patients of Atlanta Fibroid Center® became pregnant after UFE and gave full-term birth to healthy kids. Read the stories of LaMechee, Doris, and other patients.
John Lipman, MD, FSIR is a board-certified, world-renowned Interventional Radiologist who performs UFE at the Atlanta Fibroid Center®. With over 9,000 procedures performed, he is one of the top experts in fibroids and UFE in the United States. If you have symptomatic fibroids, contact us today for a consultation. Atlanta Fibroid Center® and Dr. Lipman can help you become free from fibroids with UFE!
My sister just learned that she has some uterine fibroids and is worried because she is pregnant. That’s scary that there have been fibroids over 100 pounds! I’ll let her know so she can talk to a fibroid specialist about getting them removed as soon as possible so they don’t grow this big.
I have been told by my doctor that I have fibroids up to 6 cm. I am currently 3 months pregnant. This morning I had bleeding a little bit of clotting. The bleeding has gotten lighter. Should I be worried??
I was told I had fibroid during my first ultrasound, now I’m 4 month pregnant and I’m currently feeling a severe pains…I’m so worried, I don’t know what to do.
Am 6month pregnant and I Have fibroid,sine
Yesterday have been having pain under my
Stomach,I have cervical fibroid and
Subserosal pedunculated fibroid, please
What can I do,am in my second trimester
IAM five weeks pregnant with utrine fibroid accompany with heavy bleeding and clothing should I be worried? Am I still pregnant