Autoimmune diseases affect fertility through multiple routes, from depleting egg reserves and disrupting ovulation to attacking embryos during implantation and triggering pregnancy loss. The connections are wide-ranging and condition-specific: antiphospholipid syndrome can cause recurrent miscarriage, thyroid autoimmunity can quietly erode ovarian reserve, and lupus can accelerate reproductive aging by years. Because autoimmune conditions disproportionately affect women of childbearing age, these overlaps matter to a large number of people trying to conceive, and they often go unrecognized until fertility problems have already taken hold.
Why an Overactive Immune System Threatens Reproduction
Successful pregnancy requires the immune system to do something unusual: tolerate a genetically foreign organism growing inside the body. The placenta and uterine lining engage in an elaborate negotiation with immune cells, dialing down inflammatory responses in some areas while maintaining protective ones in others. When autoimmune disease disrupts that balance, inflammation can persist where it shouldn’t. Specialized immune cells in the uterine lining, called uterine natural killer cells, appear at higher levels in women experiencing recurrent implantation failure during fertility treatment compared to controls.
That immune disruption doesn’t just affect implantation. Autoantibodies, the misguided proteins at the heart of many autoimmune diseases, can target ovarian tissue, placental cells, thyroid hormones that regulate the reproductive system, and even sperm. The result is a web of potential problems spanning conception, implantation, and the maintenance of early pregnancy. Each autoimmune condition creates its own particular pattern of risk.
Antiphospholipid Syndrome and Pregnancy Loss
Antiphospholipid syndrome (APS) is one of the most clinically significant autoimmune causes of pregnancy failure. In APS, the immune system produces antibodies that target cell-membrane components called phospholipids, and these antibodies are strongly linked to recurrent miscarriage, fetal growth restriction, and preeclampsia. For years, the damage was attributed mainly to blood clots forming in the placenta and cutting off the fetus’s supply. That picture has grown more complicated. Accumulating evidence shows that antiphospholipid antibodies directly harm trophoblast cells, the early placental cells responsible for anchoring the embryo and building its blood supply, even when no clotting occurs.1PubMed Central. Trophoblast Cell Function in the Antiphospholipid Syndrome
Research using mouse models has demonstrated that complement activation, a cascade of immune proteins that amplifies inflammation, plays a causative role in APS-related pregnancy loss. Blocking that complement cascade rescued pregnancies in mice, and heparin’s benefit in APS appears to work partly by dampening complement on trophoblast cells rather than solely by preventing clots.2PubMed Central. Antiphospholipid antibodies and pregnancy loss: a disorder of inflammation A 2025 review described the full scope of immune disruption at the maternal-fetal interface in obstetric APS, including excessive neutrophil trap formation, dysfunction of uterine immune cells, and dysregulated B cell responses that collectively create a sustained pro-inflammatory environment hostile to placental development.3PubMed Central. Immune-mediated mechanisms and maternal-fetal interface dysfunction in obstetric antiphospholipid syndrome
Treatment for APS-related pregnancy loss typically involves heparin plus low-dose aspirin. In one early trial, 80% of women receiving that combination delivered a viable infant, compared to 44% on aspirin alone.4PubMed. Antiphospholipid antibody-associated recurrent pregnancy loss: treatment with heparin and low-dose aspirin is superior to low-dose aspirin alone A pooled analysis of five trials totaling nearly 1,300 women found that heparin plus aspirin improved live birth rates compared to aspirin alone, though the certainty of the evidence was graded as low.5PubMed Central. Antithrombotic therapy to prevent recurrent pregnancy loss in antiphospholipid syndrome-What is the evidence? It’s worth stressing that this treatment specifically targets APS. A large trial in women with unexplained recurrent miscarriage (no APS diagnosis) found no benefit from aspirin plus heparin over placebo.6PubMed. Aspirin plus heparin or aspirin alone in women with recurrent miscarriage
Thyroid Autoimmunity and Its Quiet Effect on Egg Reserve
Autoimmune thyroid disease, which includes Hashimoto’s thyroiditis and Graves’ disease, is the most common autoimmune condition in women of reproductive age. Even when thyroid hormone levels remain in the normal range, the presence of thyroid peroxidase antibodies (anti-TPO) appears to be an independent problem for fertility. A study of women undergoing fertility evaluation found that those who tested positive for anti-TPO had markedly lower ovarian reserve markers: their AMH levels averaged less than half those of antibody-negative women, and their follicle counts were roughly halved as well.7PubMed Central. Autoimmune Thyroid Disease and Female Fertility: Does Anti-TPO Accelerate Ovarian Aging? The association was strongest in younger women under 35, suggesting that thyroid autoimmunity may speed up what amounts to premature ovarian aging.
The effects carry over into IVF. A systematic review and meta-analysis covering nearly 4,900 women found that those with thyroid autoimmunity had a roughly 27% lower chance of live birth per IVF cycle and about a 44% higher risk of miscarriage, even though the number of eggs retrieved and fertilization rates looked similar.8Human Reproduction Update. The impact of thyroid autoimmunity on IVF/ICSI outcome: a systematic review and meta-analysis In other words, thyroid autoimmunity may not prevent conception so much as undermine the pregnancy’s ability to stick. A separate meta-analysis found that the problem scales with antibody levels: women with anti-TPO above 100 IU/mL had roughly double the miscarriage rate of antibody-negative women during assisted reproduction.9PubMed. High level of thyroid peroxidase antibodies as a detrimental risk of pregnancy outcomes in euthyroid women undergoing ART: A meta-analysis
Whether treating thyroid autoimmunity directly improves pregnancy outcomes is less clear. One study of IVF patients with thyroid autoimmunity found that adding aspirin plus prednisone did not improve clinical pregnancy or miscarriage rates.10PubMed Central. IVF/ICSI outcomes of euthyroid infertile women with thyroid autoimmunity: does treatment with aspirin plus prednisone matter? This is an area where the evidence is still thin, and clinicians often focus on keeping thyroid hormone levels well-optimized rather than trying to suppress the antibodies themselves.
Lupus and Accelerated Ovarian Aging
Systemic lupus erythematosus poses a double threat to fertility: the disease itself and the drugs used to control it. A 2024 meta-analysis synthesizing data across multiple studies confirmed that women with lupus have significantly lower AMH levels and lower follicle counts than women without the disease.11PubMed. Effect of systemic lupus erythematosus on the ovarian reserve: A systematic review and meta-analysis Subgroup analysis showed that adult-onset lupus was associated with the clearest reductions, while women diagnosed with juvenile-onset lupus didn’t show the same degree of AMH loss, though their follicle counts were still lower. Disease-related organ damage, measured by cumulative damage scores, has been independently linked to lower AMH, suggesting that the longer lupus goes unchecked, the more it erodes reproductive capacity.12PubMed. Anti-müllerian hormone and ovarian reserve in systemic lupus erythematosus
One complicating factor is cyclophosphamide, a potent immunosuppressive drug used for severe lupus flares. Cyclophosphamide is well known to be toxic to the ovaries, and guidelines now often recommend fertility preservation before a course of it. But even among lupus patients who have never received cyclophosphamide, ovarian reserve markers tend to be lower than in healthy women of the same age.13PubMed Central. Evaluation of the Ovarian Reserve in Women With Systemic Lupus Erythematosus That points to the disease process itself, likely chronic inflammation and autoantibodies targeting ovarian tissue, as a separate contributor.
Rheumatoid Arthritis and Subfertility
Women with rheumatoid arthritis take longer to conceive. In one study, nearly half of RA patients reported at least one period of subfertility, and the most common diagnoses were unexplained subfertility and absent ovulation, both occurring more frequently than in the general population.14PubMed Central. Subfertility in Women With Rheumatoid Arthritis and the Outcome of Fertility Assessments Active inflammation itself may be a key driver. A review of ART outcomes found that women with RA, along with those with Crohn’s disease and ulcerative colitis, tended to have problems with low implantation rates or early embryo development during fertility treatment.15PubMed Central. The Efficacy of Assisted Reproduction in Women with a Wide Spectrum of Chronic Diseases – A Review
On the medication front, the news is actually somewhat reassuring. A prospective study found that women with arthritis taking methotrexate, either alone or combined with TNF-alpha inhibitors, had a slower rate of AMH decline over time than arthritis patients taking no medication.16PubMed Central. Association between arthritis treatments and ovarian reserve: a prospective study The interpretation is that controlling disease activity protects the ovaries rather than harming them. Other studies looking at short-term methotrexate use similarly found no negative effect on AMH levels.17PubMed. Levels of serum anti-Müllerian hormone, a marker for ovarian reserve, in women with rheumatoid arthritis The catch is that methotrexate is a known teratogen and must be stopped well before conception, so timing disease management around pregnancy planning requires careful coordination with a rheumatologist.
Celiac Disease and Unexplained Infertility
Celiac disease is an autoimmune reaction to gluten that primarily damages the small intestine, but its effects are systemic. Several studies have examined whether undiagnosed celiac disease is hiding behind cases of unexplained infertility. Results are mixed but intriguing. A U.S. prospective study found a celiac prevalence of about 5.9% among women with unexplained infertility, compared to an expected rate of about 1.3% based on age-matched general population data.18PubMed Central. Increased Prevalence of Celiac Disease in Patients with Unexplained Infertility in the United States: A Prospective Study However, a later meta-analysis pooling nine studies reached a more modest estimate, with a biopsy-confirmed celiac prevalence of about 0.6% among women with unexplained infertility.19PubMed Central. The prevalence of celiac disease in women with infertility—A systematic review with meta‐analysis
The discrepancy likely reflects differences in study design, population screening rates, and diagnostic criteria. The practical takeaway is that routine celiac screening for all infertile women probably isn’t justified by current evidence, but testing makes sense when infertility is otherwise unexplained, especially if there are subtle signs like iron-deficiency anemia, low body weight, or a family history of celiac disease. When celiac disease is found and treated with a strict gluten-free diet, reproductive outcomes often improve, likely because nutrient absorption normalizes and systemic inflammation subsides.
Endometriosis at the Intersection of Inflammation and Fertility
Endometriosis affects roughly 6 to 10% of reproductive-age women, and close to half of those affected experience infertility.20PubMed Central. Implications of immune dysfunction on endometriosis associated infertility While endometriosis is not a classic autoimmune disease, it shares many immune features with autoimmune conditions: chronic inflammation, autoantibodies, dysfunctional immune surveillance, and heightened oxidative stress. The peritoneal fluid in women with endometriosis is essentially a toxic bath of inflammatory molecules that can impair sperm function, damage egg quality, and make the uterine lining less receptive to an embryo.21PubMed Central. Endometriosis and Oocyte Quality: Morphological Alterations, Developmental Competence, and Modifiable Strategies for Reproductive Longevity
When endometriosis coexists with a diagnosed autoimmune disease, the impact on fertility compounds. A multicenter study comparing women who had both endometriosis and autoimmune disease against women with endometriosis alone found that the dual-diagnosis group had significantly lower embryo cleavage and implantation rates during IVF. Implantation rates were roughly 11% in the autoimmune group versus about 18% in controls.22PubMed Central. Concomitant Autoimmunity in Endometriosis Impairs Endometrium–Embryo Crosstalk at the Implantation Site: A Multicenter Case-Control Study The study pointed to disrupted communication between the uterine lining and the embryo as a key mechanism.
Premature Ovarian Insufficiency With an Autoimmune Cause
Premature ovarian insufficiency (POI), sometimes called premature menopause, means the ovaries stop functioning normally before age 40. In the majority of cases the cause is unknown, but autoimmunity accounts for somewhere between 4% and 30% of cases, a wide range that reflects how difficult autoimmune POI is to diagnose with certainty.23PubMed Central. Premature ovarian insufficiency (POI) and autoimmunity-an update appraisal Women with autoimmune POI often have antibodies targeting steroid-producing cells or ovarian tissue itself, and they frequently have other autoimmune conditions alongside it, particularly autoimmune thyroid disease or adrenal insufficiency. Because there is no single reliable test that definitively identifies an autoimmune cause, screening for common autoantibodies is recommended as part of the POI workup.
When Autoimmunity Affects Male Fertility
The conversation about autoimmunity and fertility usually centers on women, but men are not exempt. Antisperm antibodies can develop after vasectomy reversal, testicular injury, infection, or sometimes with no identifiable trigger. These antibodies bind to sperm and can impair motility, block the sperm’s ability to penetrate an egg, or cause sperm to clump together. Immunological infertility from antisperm antibodies can occur even when a semen analysis looks normal in terms of sperm count and shape.24PubMed Central. Role of Antisperm Antibodies in Infertility, Pregnancy, and Potential for Contraceptive and Antifertility Vaccine Designs: Research Progress and Pioneering Vision Treatment options include corticosteroids (which carry significant side effects) and IVF with intracytoplasmic sperm injection, which physically bypasses the antibodies by injecting a single sperm directly into the egg.
Vitamin D, Immune Regulation, and Pregnancy
Vitamin D has emerged as an interesting thread connecting autoimmune disease and reproductive outcomes. It plays a role in regulating T cells, including the regulatory T cells that are critical for allowing the immune system to tolerate a pregnancy. Deficiency has been linked both to greater autoimmune disease activity and to adverse pregnancy outcomes including recurrent miscarriage and preeclampsia.25PubMed Central. Immunomodulatory Effects of Vitamin D in Pregnancy and Beyond Vitamin D deficiency is common in pregnant women even with prenatal vitamin use, and is especially prevalent in women with lupus, antiphospholipid syndrome, and Hashimoto’s thyroiditis.
Research suggests that vitamin D promotes a shift in immune balance toward the tolerant profile needed for pregnancy, and that deficiency may tip the scales toward rejection of the embryo.26PubMed. Vitamin D, autoimmunity and recurrent pregnancy loss: More than an association Whether vitamin D supplementation actually reduces miscarriage risk in women with autoimmune conditions remains an open question, but most reproductive immunologists consider it a low-risk intervention worth optimizing during preconception planning.
Navigating Fertility Treatment With Autoimmune Disease
IVF and related treatments are common paths for women with autoimmune disease, but outcomes can vary by condition. Women with ulcerative colitis, Crohn’s disease, and rheumatoid arthritis have been shown to struggle with implantation and early embryo development during IVF cycles, while women with well-managed hypothyroidism or type 1 diabetes appear to have live birth rates comparable to other IVF patients.15PubMed Central. The Efficacy of Assisted Reproduction in Women with a Wide Spectrum of Chronic Diseases – A Review The difference seems to come down to how well systemic inflammation is controlled before and during treatment. For women with APS, IVF combined with appropriate anticoagulation is standard practice. For thyroid autoimmunity, ensuring thyroid hormone levels are tightly controlled appears to matter more than the antibody status itself.
Fertility preservation is a separate but critical consideration. Women with lupus facing cyclophosphamide treatment, or women with any progressive autoimmune condition that may worsen ovarian function over time, may benefit from freezing eggs or embryos before disease or treatment takes a further toll on ovarian reserve. This is a conversation worth having early, ideally at diagnosis rather than when pregnancy is actively being pursued.
Fetal Cells That Linger for Decades
One of the stranger overlaps between pregnancy and autoimmunity is microchimerism: during pregnancy, small numbers of fetal cells cross the placenta and take up residence in the mother’s body, where they can persist for decades. Maternal cells similarly transfer into the fetus. This two-way cellular exchange is normal and occurs in virtually all pregnancies. While microchimerism is common in healthy women, studies have found higher proportions of fetal cells in women with certain autoimmune diseases, particularly systemic sclerosis, rheumatoid arthritis, and Sjögren’s syndrome.27PubMed Central. Feto-maternal microchimerism: Memories from pregnancy
The hypothesis is that these genetically foreign fetal cells can sometimes trigger or worsen autoimmune responses in the mother, essentially being recognized as “other” and sparking immune attacks that also damage the mother’s own tissues. This may partly explain why some autoimmune diseases spike or first appear in the years following pregnancy.28PubMed Central. Autoimmune disease during pregnancy and the microchimerism legacy of pregnancy But microchimerism may also be protective in some contexts: fetal cells have been found differentiating into functional tissue in the mother, potentially aiding repair. The relationship is genuinely double-edged, and the field is still working out when these leftover cells help and when they harm.29PubMed Central. The role of fetal microchimerism in autoimmune disease
Why Women Bear the Brunt
About 80% of autoimmune disease cases occur in women, and the fertility years are peak onset time for many of these conditions. One evolutionary hypothesis proposes that female immune systems evolved to be more aggressive because pregnancy, with its invasive placenta and genetically foreign fetus, demands intense immune surveillance. That heightened baseline immune activity carries a tradeoff: better defense against infections and cancer, but greater susceptibility to the immune system turning on the body’s own tissues. Changes in reproductive patterns in industrialized societies, such as fewer pregnancies, later first births, and shorter breastfeeding duration, may further exacerbate this evolved tendency toward autoimmunity.
The practical implication is that women diagnosed with any autoimmune condition in their twenties or thirties should consider reproductive planning as part of their disease management from the start. Ovarian reserve testing with AMH and follicle counts can provide a snapshot of where things stand, even before fertility is an immediate goal. Many autoimmune conditions are manageable with medications that are compatible with pregnancy planning, but the transition between treatment regimens takes time, and knowing your baseline reserve helps you and your medical team make informed decisions about timing.