Hydroxychloroquine: Understanding Its Role in Reproductive Immunology

Introduction

For some individuals and couples, repeated miscarriages, failed IVF cycles, or difficulty achieving a successful pregnancy can occur despite extensive testing and treatment. While hormonal, genetic, and anatomical factors are often evaluated, growing attention has been given to the role of the immune system in reproduction.

One medication that has gained interest in reproductive immunology is hydroxychloroquine (HCQ). Originally developed to prevent and treat malaria, hydroxychloroquine has been used safely for decades to manage autoimmune diseases such as lupus and rheumatoid arthritis.

Today, some reproductive specialists use hydroxychloroquine in selected patients with recurrent pregnancy loss, recurrent implantation failure, or autoimmune-related fertility challenges.

What Is Hydroxychloroquine?

Hydroxychloroquine is an immune-modulating medication rather than a traditional immunosuppressant.

It is commonly prescribed for:

• Systemic lupus erythematosus (SLE)
• Rheumatoid arthritis
• Sjögren’s syndrome
• Antiphospholipid syndrome (APS)
• Other autoimmune conditions

Unlike medications that strongly suppress the immune system, hydroxychloroquine helps regulate immune activity and reduce excessive inflammation.

Why Might Hydroxychloroquine Be Used in Reproductive Failure?

Hydroxychloroquine may be considered when immune dysfunction or autoimmune disease is suspected to contribute to reproductive challenges.

Recurrent Pregnancy Loss

Several studies suggest that hydroxychloroquine may help improve pregnancy outcomes in some women with recurrent pregnancy loss, particularly when autoimmune factors are involved.

Antiphospholipid Syndrome (APS)

APS is an autoimmune condition associated with recurrent miscarriage, implantation failure, placental insufficiency, and pregnancy complications.

Hydroxychloroquine may be used alongside standard treatments such as low-dose aspirin and anticoagulation therapy to improve pregnancy outcomes in selected patients.

Systemic Lupus Erythematosus (SLE)

Women with lupus who become pregnant are often advised to continue hydroxychloroquine throughout pregnancy because it may help reduce disease activity and improve maternal and fetal outcomes.

Recurrent Implantation Failure

Some reproductive immunologists prescribe hydroxychloroquine for patients with recurrent implantation failure when immune activation or inflammation is suspected.

Elevated Inflammatory Activity

Hydroxychloroquine may help reduce excessive immune activation and inflammatory signaling that could interfere with implantation and placental development.

How Does Hydroxychloroquine Work?

Hydroxychloroquine affects several pathways involved in immune regulation.

Potential effects include:

• Reducing inflammatory cytokine production
• Modulating immune cell activity
• Decreasing abnormal immune activation
• Reducing autoantibody-mediated inflammation
• Supporting maternal-fetal immune tolerance

Unlike some immunosuppressive medications, hydroxychloroquine is generally considered a gentler immune-modulating therapy.

Does Hydroxychloroquine Work for Everyone?

No.

Hydroxychloroquine is not a universal treatment for infertility, recurrent miscarriage, or implantation failure.

Its potential benefits appear to be greatest in patients with:

• Autoimmune disease
• Antiphospholipid antibodies
• Systemic inflammation
• Suspected immune-mediated reproductive failure

Research is ongoing, and while many studies are encouraging, further investigation is needed to determine which patients benefit most.

Is There a Standard Hydroxychloroquine Dose?

One of the most important points for patients to understand is that there is no universally accepted or standardized hydroxychloroquine protocol in reproductive immunology.

Different fertility specialists and reproductive immunologists may prescribe different treatment regimens depending on:

• Underlying diagnosis
• Autoimmune status
• Laboratory findings
• Reproductive history
• Previous treatment outcomes
• Pregnancy progress

Many experts believe that hydroxychloroquine treatment should be individualized and guided by careful clinical assessment and ongoing monitoring.

The goal is not simply to suppress the immune system but to promote a balanced immune environment that supports implantation and pregnancy while minimizing unnecessary treatment.

Because immune activity can change throughout fertility treatment and pregnancy, therapy may need to be adjusted based on the patient’s evolving clinical situation.

Potential Benefits

In appropriately selected patients, hydroxychloroquine may offer:

• Reduced immune-mediated inflammation
• Improved implantation environment
• Improved pregnancy maintenance
• Reduced autoimmune disease activity
• Potential improvement in live birth outcomes
• Improved placental function in some autoimmune conditions

However, benefits are not guaranteed and vary from patient to patient.

Potential Side Effects

Hydroxychloroquine is generally considered one of the safest immune-modulating medications used during pregnancy.

Possible side effects include:

• Nausea
• Stomach upset
• Headache
• Dizziness
• Skin rash
• Changes in appetite

Rarely, long-term use may affect the retina of the eye. For this reason, patients taking hydroxychloroquine for extended periods may require periodic ophthalmologic examinations.

Importantly, hydroxychloroquine has been extensively studied in pregnancy and is generally considered safe for both mother and baby when prescribed appropriately.

The Bottom Line

Hydroxychloroquine is an immune-modulating medication that may help selected patients with autoimmune disease, recurrent pregnancy loss, recurrent implantation failure, or other forms of reproductive failure associated with immune dysfunction.

While research continues to evolve, hydroxychloroquine has become an important tool in reproductive immunology because of its ability to reduce inflammation, regulate immune responses, and support pregnancy while maintaining a favorable safety profile.

There is currently no universally accepted hydroxychloroquine protocol in reproductive immunology. Many specialists advocate for individualized treatment plans based on a patient’s immune profile, reproductive history, underlying medical conditions, and response to therapy. Close monitoring and collaboration with an experienced fertility specialist or reproductive immunologist are essential to optimize treatment outcomes.

References

1. Sciascia S, Branch DW, Levy RA, et al. The impact of hydroxychloroquine treatment on pregnancy outcome in women with antiphospholipid antibodies. Autoimmunity Reviews. 2016;15(5):504–508.
   DOI: https://doi.org/10.1016/j.autrev.2016.01.019
2. Mekinian A, Lazzaroni MG, Kuzenko A, et al. The efficacy of hydroxychloroquine for obstetrical outcome in anti-phospholipid syndrome: A systematic review. Autoimmunity Reviews. 2015;14(6):498–502.
   DOI: https://doi.org/10.1016/j.autrev.2015.01.012
3. Seo MR, Kim HO, Lim JH, et al. Hydroxychloroquine treatment and pregnancy outcomes in women with autoimmune disease. Lupus. 2019;28(5):561–569.
   DOI: https://doi.org/10.1177/0961203319837284
4. Sperber K, Hom C, Chao CP, et al. Systematic review of hydroxychloroquine use during pregnancy. Pediatric Rheumatology. 2009;7:9.
   DOI: https://doi.org/10.1186/1546-0096-7-9
5. Eudy AM, Siega-Riz AM, Engel SM, et al. Effect of hydroxychloroquine on pregnancy outcomes in women with systemic lupus erythematosus: A systematic review and meta-analysis. Lupus Science & Medicine. 2018;5:e000280.
   DOI: https://doi.org/10.1136/lupus-2018-000280
6. Saito S, Nakashima A, Shima T, Ito M. Th1/Th2/Th17 and regulatory T-cell paradigm in pregnancy. American Journal of Reproductive Immunology. 2010;63(6):601–610.
   DOI: https://doi.org/10.1111/j.1600-0897.2010.00852.x
7. American Society for Reproductive Immunology (ASRI). Evidence-based recommendations for immunotherapy in recurrent pregnancy loss and reproductive failure. 2025. (Guideline document).

Tacrolimus: Understanding Its Role in Reproductive Immunology

Introduction

For some individuals and couples, repeated IVF failures, recurrent miscarriages, or difficulty achieving a successful pregnancy occur despite having good-quality embryos and no obvious explanation. In recent years, reproductive specialists have increasingly explored the role of the immune system in fertility and pregnancy.

One medication that has gained attention in reproductive immunology is tacrolimus, an immune-modulating drug originally developed to prevent organ transplant rejection. In carefully selected patients, tacrolimus may help create a more favorable immune environment for embryo implantation and pregnancy.

What Is Tacrolimus?

Tacrolimus is an immunomodulatory medication that belongs to a group of drugs called calcineurin inhibitors.

It has been used for many years to:

• Prevent rejection after organ transplantation
• Treat certain autoimmune diseases
• Control excessive immune activity

In reproductive medicine, tacrolimus is typically prescribed at much lower doses than those used in transplant patients.

Why Might Tacrolimus Be Used in Reproductive Failure?

Some reproductive immunologists prescribe tacrolimus when there is evidence that excessive immune activation may be interfering with implantation or pregnancy.

Recurrent Implantation Failure (RIF)

Some patients undergo multiple embryo transfers with high-quality embryos but do not achieve pregnancy. Research suggests that immune imbalances may contribute to implantation failure in a subset of these patients.

Recurrent Pregnancy Loss (RPL)

For patients experiencing repeated miscarriages, immune-related inflammation may sometimes be considered as a contributing factor after more common causes have been excluded.

Elevated Th1 Immune Activity

One of the most common reasons tacrolimus is prescribed in reproductive immunology is the presence of elevated Th1-type immune responses.

Th1 cells produce inflammatory substances that may interfere with implantation and early pregnancy if present in excess. Tacrolimus may help reduce this inflammatory activity and promote a more balanced immune environment.

Autoimmune Disorders

Patients with autoimmune diseases may occasionally receive tacrolimus as part of their overall treatment plan when immune dysfunction is believed to affect reproductive outcomes.

How Does Tacrolimus Work?

Tacrolimus works differently from prednisone.

Rather than broadly suppressing inflammation, tacrolimus selectively influences certain immune pathways and T-cell activity.

Potential effects include:

• Reducing excessive Th1 immune responses
• Modulating T-cell activation
• Promoting maternal immune tolerance
• Supporting implantation and placental development
• Reducing harmful inflammatory signaling

The goal is to create an immune environment that is more supportive of embryo implantation and pregnancy.

Does Tacrolimus Work for Everyone?

No.

Tacrolimus is not appropriate for all fertility patients and should not be considered a routine treatment for reproductive failure.

Research suggests that the greatest benefit may occur in carefully selected patients who demonstrate evidence of immune dysregulation, particularly elevated Th1 immune activity.

Some studies have reported improved implantation, clinical pregnancy, and live birth rates in selected patients with recurrent implantation failure, while others emphasize the need for additional research.

As a result, many specialists reserve tacrolimus for patients with documented immune abnormalities rather than prescribing it routinely.

Is There a Standard Tacrolimus Dose?

One of the most important points for patients to understand is that there is no universally accepted or standardized tacrolimus dosing protocol in reproductive immunology.

Published studies have used different doses, treatment schedules, and monitoring strategies. Clinical practices also vary significantly among reproductive immunologists.

Many specialists believe that tacrolimus treatment should be individualized based on:

• Immune testing results
• Degree of immune activation
• Reproductive history
• Previous treatment response
• Pregnancy progress

The goal is not simply to prescribe tacrolimus, but to achieve an appropriate balance within the immune system while minimizing potential risks.

Because immune activity can change during treatment and pregnancy, dosage adjustments may sometimes be necessary. This is why close medical supervision and ongoing monitoring are essential.

Potential Benefits

In appropriately selected patients, tacrolimus may offer:

• Improved implantation rates
• Improved pregnancy rates
• Reduced inflammatory immune responses
• Better maternal-fetal immune tolerance
• Potential improvement in live birth outcomes

However, benefits are not guaranteed and may vary considerably between individuals.

Potential Side Effects

Although doses used in reproductive medicine are generally lower than those used in transplant medicine, tacrolimus can still cause side effects.

Possible side effects include:

• Headache
• Tremor
• Increased blood pressure
• Elevated blood sugar
• Nausea
• Kidney function changes
• Increased susceptibility to infections

Although tacrolimus crosses the placenta, current evidence from pregnancy studies, particularly in transplant and autoimmune disease patients, has not shown a significant increase in major birth defects, and it is generally considered compatible with pregnancy when used under careful specialist supervision.

The Bottom Line

Tacrolimus is an immune-modulating medication that may help selected patients with recurrent implantation failure, recurrent pregnancy loss, or other forms of reproductive failure associated with immune dysfunction.

However, reproductive immunology remains a rapidly evolving field. There is currently no universally accepted tacrolimus protocol, and treatment should be individualized based on a patient’s immune profile, reproductive history, and response to therapy.

Many reproductive immunologists advocate for personalized treatment plans and close immune monitoring rather than a one-size-fits-all approach. Patients considering tacrolimus should discuss the potential benefits, risks, and uncertainties with an experienced fertility specialist or reproductive immunologist.