If you have a desmoid tumor (or had one in the past) and are thinking about having children, it’s normal to feel unsure. You may wonder whether it’s safe to get pregnant, whether treatment could affect your fertility, or whether pregnancy could cause a tumor to grow.

Part of the challenge is that desmoid tumors are rare. Because of that, fertility and pregnancy have not been studied as thoroughly as they have for more common conditions. Much of what we know comes from small studies and doctors’ experience rather than large, definitive research. That means there are still unknowns, but there is also reassuring information that can help guide decisions.

This article focuses on how desmoid tumors may affect future fertility, what’s known so far, what remains uncertain, and why talking openly with your doctor is so important.

How Desmoid Tumors Can Relate to Fertility

Desmoid tumors, sometimes called aggressive fibromatosis, are rare growths that form in connective tissue. They are not cancerous and do not spread to other parts of the body. However, they can still cause problems by growing into nearby muscles, organs, or nerves.

These tumors can develop almost anywhere in the body, including the abdominal wall or pelvis. When a tumor is near reproductive organs, questions about fertility and pregnancy often come up. It’s also important to know that desmoid tumors behave very differently from person to person. For example:

• Some tumors grow very slowly or stop growing on their own.
• Others grow more quickly and need treatment.
• Some people never need treatment at all, while others do.

Because desmoid tumors behave so differently from person to person, fertility concerns are also different for everyone. There is no single rule that applies to everyone with a desmoid tumor.

Is It Safe To Get Pregnant if You’ve Had a Desmoid Tumor?

For many people, pregnancy can be safe after a desmoid tumor, but the answer depends on personal medical details.

Current guidance suggests that pregnancy is usually safe for people with a history of desmoid tumors. In people whose tumors developed during pregnancy and were later removed, the risk of the tumor coming back appears to be low. For those who already had a desmoid tumor before becoming pregnant and were being monitored rather than treated, pregnancy outcomes are generally good.

In studies that followed adults with desmoid tumors during pregnancy, most complications were not directly caused by the tumors themselves. Most pregnancies progressed normally, and serious problems were uncommon.

That said, doctors usually recommend closer monitoring during pregnancy. This helps catch any changes early and allows care teams to respond if a tumor starts to grow or cause symptoms.

Can Pregnancy Cause a Desmoid Tumor To Grow or Come Back?

Sometimes pregnancy can cause a desmoid tumor to grow or return, but this does not happen to everyone. Hormonal changes during pregnancy, especially increases in estrogen, are thought to influence desmoid tumor growth. Some people notice that a tumor grows during pregnancy, while others see little or no change. In follow-up studies:

• Many tumors that appeared during pregnancy showed some growth while pregnant.
• Most were managed with careful observation rather than immediate treatment.
• About half of the women underwent surgery during or after pregnancy, according to the journal Annals of Surgery.

Note this research is from 2014, when surgery was more commonly performed than it is today.

For people who had a desmoid tumor before pregnancy, some experienced tumor growth or recurrence during or after pregnancy. Even so, most cases were handled with planned treatment or continued monitoring rather than emergency care.

It’s also important to know that tumor growth during pregnancy does not automatically mean something is wrong. In many cases, tumors slow down or stabilize again after delivery.

Can Desmoid Tumor Treatments Affect Future Fertility?

This is one of the most important questions, and also one of the hardest to answer clearly.

Some treatments for desmoid tumors may affect fertility, while others are unlikely to. The risk depends on factors like the type of treatment used, how long it’s taken, and a person’s age at the time of treatment. Here’s how different treatments may play a role.

Surgery

There is no evidence that surgery alone affects fertility unless there are surgical complications. Fertility risks depend on how complex the surgery needs to be and what structures are involved.

Chemotherapy

Traditional chemotherapy is used less often today but may still be recommended in certain cases. Some chemotherapy drugs can damage the ovaries or sperm-producing cells. This can lower fertility or lead to early menopause.

Targeted Therapies

Newer targeted therapies have raised new fertility questions. One medication, nirogacestat (Ogsiveo), has shown strong results in controlling desmoid tumors. However, according to the journal JAMA Oncology, some females of reproductive age who take this drug have reported ovarian dysfunction. In some cases:

• Menstrual periods stopped during treatment.
• Hormone levels changed.
• These effects may be reversible, but more research is needed.

Because of this uncertainty, fertility counseling before starting treatment is especially important.

Can You Get Pregnant While Taking Desmoid Tumor Medications?

In most cases, pregnancy is not recommended while taking medications for desmoid tumors.

Many treatment options used for desmoid tumors are not considered safe during pregnancy and could pose risks to a developing baby. This includes targeted therapies and chemotherapy. For that reason, many choose to avoid or postpone pregnancy during treatment. If having children is an important goal, your doctor may discuss options such as:

• Timing treatment around pregnancy plans
• Adjusting or pausing medications
• Waiting until treatment is completed before trying to conceive

These decisions are very personal and should be made with guidance from your care team.

Does Having a Desmoid Tumor Affect Your Baby’s Health?

Based on what’s known so far, desmoid tumors themselves do not appear to harm the baby.

In studies that followed pregnancy with desmoid tumors, postpartum outcomes were generally positive. Complications were not directly tied to the presence of the tumor.

Desmoid tumors are not infectious and cannot be passed to a baby during pregnancy. In rare cases, desmoid tumors are linked to an inherited condition called familial adenomatous polyposis (FAP). If that applies to someone, genetic counseling may be recommended, but this situation is uncommon.

Why Fertility Preservation Is Worth Discussing Early

Because some treatment options may affect fertility, many specialists encourage talking about fertility preservation as early as possible, ideally before treatment begins. Depending on your situation, this might include:

• Freezing eggs or embryos
• Freezing sperm
• Meeting with a fertility specialist to understand options

These conversations can feel overwhelming during a diagnosis, but many people later say they were glad fertility was discussed early rather than after changes had already happened. Even if you’re not sure whether you want children, it’s still reasonable to ask your healthcare provider questions. You don’t have to decide everything right away.

Planning Ahead When Answers Aren’t Perfect

When it comes to desmoid tumors, clear answers are often limited. Much of what’s known about fertility and pregnancy comes from observation rather than definitive studies. Even so, current evidence suggests that many people with desmoid tumors can safely pursue pregnancy and build families, especially with thoughtful planning and close medical follow-up.

The most important step is open communication. Talking openly with your doctor about fertility concerns and pregnancy goals can help make sure your care supports both your health now and your future plans.

Join the Conversation

On MyDesmoidTumorTeam, people share their experiences with desmoid tumors, get advice, and find support from others who understand.

How has thinking about future family plans shaped the questions you ask or the choices you’ve made since your desmoid tumor diagnosis? Let others know in the comments below.