What To Know About Uterine Fibroids and Pregnancy

Uterine fibroids are extremely common, affecting up to 80% of women. These noncancerous growths develop in and on your uterus. If you’ve been diagnosed with them and hope to start a family, you might wonder: Could fibroids throw a wrench in your plans to get pregnant?

Minimally invasive gynecologic surgeon Megan Billow, DO, explains how fibroids can affect fertility, what happens to fibroids during pregnancy and what treatment options may be available to you.

Can you get pregnant with uterine fibroids?

“Most women with fibroids can become pregnant and have healthy pregnancies,” Dr. Billow says. “But there are certain types of fibroids that can affect your ability to get pregnant.”

Whether fibroids impact your fertility depends largely on:

• Where they’re located
• How big they are
• How many you have

“The key factor is whether your fibroids affect your endometrium — the lining of your uterus that builds up and sloughs off during your menstrual cycle,” she adds. “Fibroids in your uterine lining can alter the shape of your uterine cavity, which can affect your ability to get pregnant.”

Dr. Billow explains the types of fibroids and how each is (or isn’t) likely to affect fertility.

Subserosal fibroids

Subserosal fibroids grow under the lining of the outer surface of your uterus. Because they don’t impact the uterine cavity, they don’t usually affect fertility.

“These fibroids can get very large,” Dr. Billow notes. “But they don’t often impact your ability to get pregnant.”

Intramural fibroids

Intramural fibroids are the most common type of fibroids, and they may or may not affect your fertility.

“Intramural fibroids impact the actual muscle of the uterus, which can push or distort the uterine cavity,” Dr. Billow explains. “If that happens, they can impact your ability to get pregnant.”

If you have intramural fibroids that aren’t causing any symptoms, your healthcare provider isn’t likely to suggest having them removed before pregnancy. But if they’re causing issues — like if you have a history of pregnancy loss — your provider may recommend fibroid removal surgery (myomectomy).

Submucosal fibroids

Submucosal fibroids are the least common type of fibroid, but the ones most likely to play a role in infertility.

They grow under the endometrium, which can distort your uterus. This significantly raises the risk of implantation failure — when a fertilized egg can’t implant into your uterine lining.

“Submucosal fibroids are the ones we’re most concerned about in terms of fertility,” Dr. Billow clarifies. “We often recommend removing them before trying to get pregnant because they can impact your ability to get pregnant. They can also increase your risk of miscarriage.”

Is pregnancy with fibroids ‘high risk’?

Having uterine fibroids doesn’t necessarily mean your pregnancy will be considered high risk. It depends on what type of fibroids you have and what symptoms they’re causing.

“Just because you have a fibroid doesn’t mean that it has to be removed prior to pregnancy,” Dr. Billow says, “and it doesn’t mean that it’s going to harm the pregnancy.”

Submucosal fibroids are the type of fibroids that are most associated with higher pregnancy risks. They can make it harder to get pregnant, stay pregnant and carry a pregnancy to full term, raising your risk of:

• Intrauterine growth restriction: Very large fibroids can take up space in the uterus, which doesn’t give the fetus enough room to grow as it should.
• Preterm labor: When fibroids take up too much space, you may experience contractions sooner than 37 weeks. This can also lead to preterm birth, which is when you give birth before the 37-week mark.
• Fetal malpresentation: Fibroids can affect the fetus’s position, leading to one that isn’t ideal for birth, like breech position, which usually requires a C-section delivery.

Large intramural fibroids may pose similar pregnancy risks, though Dr. Billow says such complications are rare.

What happens to fibroids during pregnancy?

Your hormones are at full tilt during pregnancy, especially in the first trimester. And that can fuel fibroids.

“Hormones drive fibroid growth, so there can be an increased rate of growth during the first trimester in particular,” Dr. Billow explains.

Then again, she says that this isn’t the case for everyone. You may not experience any fibroid growth during your pregnancy — or your fibroids may grow but not cause any symptoms.

In fact, many women go through pregnancy with symptomless, unproblematic uterine fibroids. Sometimes, they don’t even realize they have fibroids at all.

“It’s common to learn that you have fibroids as you’re getting your first ultrasound during pregnancy,” she notes.

Symptoms of fibroids during pregnancy

Many women who have fibroids don’t experience any symptoms at all. But when symptoms do appear, they may include:

• Abdominal pain
• Pressure in your pelvis
• Constipation
• Frequent urination
• Lower back pain
• Vaginal spotting

“In some cases, if fibroids grow and get very large, they can outgrow their blood supply,” Dr. Billow says. “This is called red degeneration, and it can lead to severe abdominal pain.”

Red degeneration is relatively rare, affecting an estimated 8% of pregnant women who have uterine fibroids. In addition to pain, it can cause symptoms like:

• Abdominal swelling
• Nausea and/or vomiting
• Fever
• Rapid heartbeat (tachycardia)

If you’re experiencing these symptoms while pregnant — especially if you’ve already been diagnosed with uterine fibroids — it’s important to seek medical care. A healthcare provider can help figure out pregnancy-safe treatment options.

Can fibroids cause miscarriage?

Most fibroids don’t pose a risk to pregnancy. The exception is submucosal fibroids, which have been shown to increase the risk of miscarriage by 60% or more.

They’re also associated with the risk of recurrent miscarriage, or having three or more miscarriages in a row.

“We typically recommend removing submucosal fibroids before attempting to get pregnant, especially if you’re going to be going through IVF or other fertility treatments,” Dr. Billow says.

But, she adds that having a myomectomy can also have an effect on your likelihood of conceiving and carrying a future pregnancy.

How are uterine fibroids treated during pregnancy?

Asymptomatic uterine fibroids don’t require any treatment, during pregnancy or otherwise. But if yours are causing symptoms, it’s important to talk to your Ob/Gyn.

“If you’re experiencing a lot of pain, they’ll work with you to come up with a pain management plan that’s safe for your pregnancy,” Dr. Billow says. That may include strategies, such as:

• Applying heat, like using a heating pad or taking warm showers
• Taking pregnancy-safe pain medication (but only under your provider’s guidance)
• Practicing healthy habits and self-care, like rest and hydration

“We don’t recommend surgery to remove fibroids during pregnancy unless it’s an emergency situation,” she adds. “And that’s very rare.”

Treatment options after pregnancy

Fibroids don’t always require treatment after pregnancy, even if that surge of hormones caused them to grow bigger at the time.

In fact, you may be in for some good news: “Though fibroids can grow during pregnancy, they can also get smaller once you’re not pregnant anymore,” Dr. Billow says.

But if your fibroids are causing symptoms after pregnancy, be sure to bring it up with your healthcare provider.

“If you have a fibroid in a certain location or of a certain size that’s causing symptoms when you’re not pregnant, they may recommend removal,” Dr. Billow explains. “Your doctor will discuss the benefits, risks and potential complications of any treatment option with you.”