Fertility, Gene Therapy, and Transplant: Questions To Ask Before Treatment

Medically reviewed by John Strouse, M.D., Ph.D.

Written by Rashida Ruwa

Posted on September 29, 2026

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Key Takeaways

Gene therapy and stem cell transplants for sickle cell disease can raise important questions about how treatment may affect fertility, and it is worth having these conversations with your care team before and after treatment.
Some treatments for sickle cell disease, including conditioning regimens used before a stem cell transplant or gene therapy, can affect the ovaries or testes and raise the risk of infertility. Sickle cell disease itself can also affect fertility over time, since repeated blood vessel blockages and iron overload from frequent transfusions may impact reproductive health.
Talking with your sickle cell care team early, asking about fertility preservation options, and connecting with a fertility specialist can help you understand your risks and make informed decisions that fit your personal goals.

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If you’re considering gene therapy or a stem cell transplant for yourself or your child with sickle cell disease (SCD), you may have questions about how treatment could affect fertility. You may also want to know if there’s anything you can do about it beforehand.

But when you’re already trying to understand what treatment will involve, it can be hard to think about fertility questions too. If you’ve had difficult experiences with healthcare providers before, you may also be less comfortable raising another concern.

Even so, it’s worth asking about fertility before and after treatment. Having those conversations can help you feel more informed and prepared as you consider treatment.

🗳️ Have you talked with a doctor about fertility risks before gene therapy or a stem cell transplant for sickle cell disease?

Yes, and it was helpful.

Yes, but it wasn’t helpful.

No, but I plan to.

No, and I don’t plan to.

Do Sickle Cell Disease Treatments Affect Fertility?

Yes, some SCD treatments can affect fertility, especially treatments that involve a conditioning regimen before a stem cell transplant or gene therapy.

A conditioning regimen is treatment given before a stem cell transplant or gene therapy to prepare the bone marrow for new blood-forming stem cells. Conditioning for stem cell transplant can vary. Current U.S. Food and Drug Administration (FDA)-approved gene therapies for SCD use myeloablative conditioning with busulfan, which can damage the ovaries or testes and increase the risk of infertility.

Some chemotherapy drugs used in conditioning regimens for bone marrow transplant, such as busulfan and cyclophosphamide, can also damage the ovaries or testes and affect egg or sperm production. As a result, people who undergo a stem cell transplant using this regimen are considered at high risk for infertility.

Your risk of fertility problems varies depending on your age, stage of sexual development at the time of treatment, and the specific conditioning regimen used.

Sickle Cell Disease Can Also Affect Fertility

SCD itself and its related complications can also affect your fertility. Repeated blockages in small blood vessels can reduce blood flow to the ovaries or testes. Over time, this can damage tissue and affect how they work.

Iron overload, an SCD complication from frequent blood transfusions, can also affect the pituitary gland. This small gland helps regulate hormones.

The risk of fertility problems can vary depending on your prior treatment and other factors. Ask your sickle cell care team about your fertility and risk for reduced fertility before treatment.

What Should You Ask About Fertility Before Treatment?

Before treatment begins, ask how it could affect your fertility, whether fertility preservation is an option, and how much time you have to decide.

Could My Treatment Affect My Fertility?

Your sickle cell care team can explain how your treatment may affect your fertility and assess your reproductive health with tests such as a semen analysis or hormone testing.

You can ask:

Could my treatment affect my fertility?
Will the effects be temporary or permanent?
Which part of treatment carries the greatest fertility risk?
Is there anything about my health or treatment plan that could increase my risk?

Should I Consider Fertility Preservation?

If your treatment could affect your fertility, ask whether fertility preservation is an option before you start treatment. Depending on your age and circumstances, options may include freezing sperm, eggs, or embryos, or preserving ovarian tissue.

However, not every fertility preservation option is suitable for everyone. SCD or its complications may affect which options are appropriate and safe for you. A fertility specialist can help you understand what’s available.

How Much Time Do I Have To Make a Decision?

Fertility preservation can take time, depending on the option you choose. Ask:

How long will fertility preservation take?
Could it delay my treatment?
How soon can I see a fertility specialist?
Will I need more than one appointment or procedure?
Is the cost of fertility preservation covered for me?

Your hematologist or sickle cell care team can refer you to a reproductive endocrinologist, a doctor who diagnoses and treats hormonal and fertility issues.

What Should You Ask About Pregnancy After Treatment?

After gene therapy or a stem cell transplant, you may wonder when it’s safe to try to conceive, whether you need contraception, and what follow-up you may need before pregnancy.

When Can I Safely Try To Have a Child?

Your hematologist or transplant specialist can tell you how long to wait before trying to conceive. The timing depends on your treatment, how your body recovers, and your overall health.

If you’re undergoing gene therapy, your care team may recommend effective contraception before treatment and for a period afterward. That may include condoms, progestin-only pills, implants, or IUDs.

Because SCD raises the risk of blood clots, combined hormonal birth control that contains estrogen, including combined pills, patches, and rings, is generally not recommended for people with SCD. Your healthcare provider can help you choose a safer birth control option based on your health and treatment.

You can ask:

Are there any restrictions on when I can become pregnant after my treatment?
Which contraception option is safest for me, given my SCD?
Does this change if I have a successful transplant?

What Follow-Up Do I Need Before Trying to Conceive?

Depending on your treatment, your sickle cell care team may recommend fertility testing. They may also review your medications and check your health before you try to conceive. They may refer you to a reproductive endocrinologist, a doctor who specializes in fertility and reproductive health.

You can ask:

Do I need fertility testing before trying to conceive?
Do I need to make any changes to my medications first?
Are there any health problems I should manage before pregnancy or trying to conceive?

Pregnancy with SCD can increase the risk of complications such as pain crises, severe anemia, blood clots, high blood pressure, and preeclampsia. A successful stem cell transplant may reduce some SCD-related pregnancy risks, but individual risks can vary.

Preconception care gives your healthcare team a chance to identify and manage these risks before pregnancy begins.

Could Treatment Affect a Future Pregnancy or Child?

Yes, chemotherapy used before a stem cell transplant carries a risk of infertility. Because of this, your care team may recommend fertility preservation before treatment and waiting before trying to conceive afterward.

Gene therapy changes blood-forming stem cells, but it does not change the genes in your eggs or sperm. This means your inherited hemoglobin type does not change after treatment.

Gene therapy or transplant also may not erase every health issue caused by SCD over time. Before treatment, it’s reasonable to ask what the treatment may change, what it may not change, and how that could affect your future health and family-planning decisions.

What Could a Child Inherit?

What a biological child may inherit depends on your specific hemoglobin genes and the genes of the other biological parent. Depending on both parents’ genes, a child could inherit sickle cell trait, SCD, or another hemoglobin condition.

If you’re planning a pregnancy, consider meeting with your hematologist or genetic counselor and asking whether the other biological parent should be tested for sickle cell trait or another hemoglobin condition. They can help you understand your chances of passing on the sickle cell gene and your family-planning options.

What Should Parents Ask About Fertility Preservation?

When you’re considering treatment for your child with SCD, fertility preservation may not be the first thing on your mind.

Here’s what you can ask:

Could this treatment affect my child’s future fertility?
Should we consider fertility preservation before treatment?
What options are available at my child’s age?
How much time would preservation take?
Could fertility preservation delay treatment?
Who should we speak with about fertility preservation?
How can my child be involved in these decisions?
Is the cost of fertility preservation covered for my child?

Fertility preservation options for children depend on age and stage of puberty. Ovarian tissue freezing is an established option for some girls who have not yet gone through puberty. For prepubertal boys, testicular tissue freezing is still experimental and is usually offered only through research programs.

A fertility specialist can explain which options are established, which are experimental, what they involve, and whether they could delay treatment.

What if Fertility Preservation Feels Out of Reach?

If fertility preservation feels out of reach because of cost, limited insurance coverage, location, or simply not knowing where to start, ask your sickle cell care team what support may be available.

They may be able to connect you with a fertility specialist, help you understand your coverage, or point you toward financial assistance programs and other resources.

A few questions worth asking:

Does my insurance cover fertility preservation?
Are there financial assistance programs?
Who can help me understand my options?
Are there other fertility-preservation options if I can’t access the recommended procedure?

Fertility is an important part of planning for gene therapy or a stem cell transplant. Talking with your care team early can help you understand your risks, learn about fertility preservation options, and make decisions that fit your goals.

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