Systemic lupus erythematosus (SLE) is a chronic, autoimmune, connective tissue disease characterized by the loss of immune tolerance, autoantibody production, immune-complex deposition and multisystem inflammatory injury. It affects women disproportionately and is most frequently diagnosed during the reproductive years, thus necessitating pregnancy counseling and pregnancy management integral components of longitudinal lupus care (1-3). Although pregnancy outcomes in SLE have improved substantially over the past two decades, affected pregnancies still carry higher rates of maternal morbidity, placental dysfunction and adverse neonatal outcomes compared with pregnancies in the general population, particularly in the presence of active disease, lupus nephritis and antiphospholipid antibodies (4-6). Accordingly, the modern approach to SLE in pregnancy extends beyond flare management alone and requires preconception optimization, individualized risk assessment, pregnancy-compatible disease control, and coordinated surveillance by rheumatology, maternal-fetal medicine, nephrology and neonatology teams when indicated (7-9).

SLE develops through multilevel interactions among genetic susceptibility, epigenetic dysregulation, sex-hormone signaling, defective clearance of apoptotic debris, type I interferon activation, aberrant B-cell and T-cell responses and complement-mediated tissue injury. In genetically predisposed individuals, environmental triggers, such as ultraviolet radiation, viral exposure, cigarette smoke, and selected drugs increase cellular stress and apoptosis. When apoptotic material is inadequately cleared, nuclear antigens remain accessible to antigen-presenting cells and autoreactive lymphocytes, facilitating the generation of antinuclear, anti-double stranded DNA, anti-Sm and antiphospholipid antibodies. The resulting immune complexes activate complement, amplify plasmacytoid dendritic cell interferon signaling, recruit inflammatory leukocytes, and produce end-organ injury in the kidneys, skin, joints, hematologic compartment, vasculature and central nervous system (10-13).

Pregnancy adds a distinct immunologic layer to this process. Successful gestation requires finely regulated maternal immune tolerance rather than generalized immunosuppression. Early implantation and placentation rely on controlled innate immune activation, decidual natural killer-cell remodeling, trophoblast-maternal crosstalk and subsequent expansion of regulatory T-cell pathways. In patients with SLE, these tolerance mechanisms may be destabilized by pre-existing interferon pathway activation, complement overactivity, endothelial dysfunction, and persistent autoantibody production. A relative shift in T-cell polarization, dysregulated Th17/Treg balance, enhanced B-cell survival and heightened cytokine signaling may, in combination, increase flare susceptibility, particularly when pregnancy begins during a period of serologic or clinical activity (7,13-15).

These mechanisms are also directly relevant to obstetric diseases. Type I interferon excess, antiphospholipid antibodies, neutrophil extracellular trap formation, complement activation, and placental vascular injury can impair spiral artery remodeling and uteroplacental perfusion, thereby linking maternal autoimmunity with preeclampsia, fetal growth restriction, preterm birth and fetal loss. Thus, the pathobiology of SLE in pregnancy should be understood not merely as baseline lupus occurring coincidentally during gestation, but as a dynamic interaction between systemic autoimmunity and the immunologic, vascular and placental adaptations required for normal pregnancy (4,5,9,13,15,16). The interaction between immune dysregulation, interferon signaling, complement activation and placental vascular injury provides a unifying framework linking systemic lupus erythematosus pathobiology with adverse obstetric outcomes. The schematic diagram presented in Fig. 1 highlights how immune-complex formation and endothelial dysfunction converge on placental insufficiency, thereby contributing to complications such as preeclampsia, fetal growth restriction and preterm birth.

The effects of pregnancy on SLE activity are best understood through the interplay between pre-pregnancy disease control, medication continuation, serologic activity and prior organ involvement rather than pregnancy alone. Contemporary cohorts suggest that flare rates are substantially lower than historically reported when conception occurs during remission or low disease activity and hydroxychloroquine is continued; nevertheless, pregnancy and the early postpartum period remain clinically vulnerable windows, particularly for patients with lupus nephritis, active serology, previous severe flares, or the withdrawal of pregnancy-compatible therapy (4-6,16-20).

The assessment of activity during pregnancy should be standardized whenever possible. The SLE Pregnancy Disease Activity Index (SLEPDAI) was specifically developed to reduce confounding by physiological gestational changes, and recent prospective evidence supports the utility of the SLE disease activity score (SLE-DAS) in early pregnancy as a predictor of subsequent maternal flares, particularly as demonstrated in first-trimester cohort analyses (18). In parallel, general disease activity instruments, such as SLEDAI, BILAG-2004 and Physician Global Assessment (PGA) remain useful when interpreted by clinicians experienced in lupus and pregnancy, while the SLICC/ACR Damage Index is relevant for defining cumulative organ injury and long-term maternal risk rather than active inflammation per se (8,18-22). From a practical standpoint, these instruments should not replace clinical judgment; however, they improve reproducibility, longitudinal monitoring and communication across specialties.

A major clinical goal is the achievement of remission or low disease activity prior to conception. A low lupus disease activity state (LLDAS) and remission at conception have been associated with fewer maternal flares and more favorable obstetric outcomes, while first-trimester disease activity and hypocomplementemia are associated with preterm birth, preeclampsia and placental insufficiency (18-20,22). Distinguishing the physiological changes of pregnancy from flare remains challenging: Mild anemia, edema, fatigue and isolated musculoskeletal discomfort may be gestational, whereas a falling complement level relative to baseline, rising anti-dsDNA titers, active urinary sediment, progressive proteinuria, thrombocytopenia, or inflammatory rash/arthritis should prompt concern for active disease. The postpartum period deserves equal attention as disease activity often intensifies following delivery, particularly within the first 6 months (16,19).

Pre-pregnancy counseling should be structured, explicit and individualized as the strongest determinant of pregnancy outcome in SLE is not the diagnosis alone, but the disease state and treatment profile at conception. Counseling should therefore move beyond a general warning that ‘complications may occur’ and instead classify the patient into an obstetric-risk framework based on current disease activity, cumulative organ damage, antibody profile, renal history, cardiovascular status, prior obstetric history and exposure to potentially teratogenic agents (4,5,8,16,23).

The ideal candidate for conception is a patient whose disease has been clinically quiescent or maintained at a low disease activity for at least 6 months, with stable renal function, controlled blood pressure, pregnancy-compatible medications and no major recent flares. By contrast, conception during active nephritis, uncontrolled hypertension, pulmonary hypertension, advanced chronic kidney disease, severe heart failure, recent stroke, or active thrombotic antiphospholipid syndrome (APS) is associated with a substantially increased maternal and fetal risk, and may justify the postponement of pregnancy until medical optimization is achieved (5,7,8,16). Counseling should explicitly differentiate modifiable risk from non-modifiable risk: Disease control, medication reconciliation, aspirin/heparin planning and the timing of conception are modifiable; prior severe nephritis and chronic organ damage define baseline vulnerability.

Medication optimization is a central component of pre-pregnancy care. Hydroxychloroquine should generally be continued; prednisone should be minimized to the lowest effective dose; azathioprine, tacrolimus and cyclosporine may be considered when indicated; and known teratogens, such as mycophenolate, methotrexate, cyclophosphamide and leflunomide require discontinuation with appropriate washout and transition planning prior to conception (8,9,15,24). In addition, counseling should address aspirin prophylaxis, anticoagulation when APS is present, anti-Ro/SSA and anti-La/SSB-related fetal surveillance, and the need for multidisciplinary care. Notably, modern data underscore that pregnancy planning and medical readiness are associated with improved reproductive outcomes than ill-timed conception during active disease or teratogenic exposure (23). A structured preconception assessment framework integrating disease activity, organ involvement, antibody profile and medication status supports individualized risk stratification and informed decision-making regarding pregnancy timing (Table I).

The pre-pregnancy evaluation in SLE should distinguish between routine background lupus surveillance and pregnancy-specific risk stratification. General SLE monitoring includes complete blood count, renal profile, liver profile, urinalysis, protein quantification, complement levels and anti-dsDNA assessment; however, in the context of pregnancy planning, these tests have a different purpose: They establish a maternal baseline against which later gestational changes can be interpreted and identify women at increased risk for flare, nephritis recurrence, preeclampsia, placental dysfunction and fetal compromise (8,16,21).

Pregnancy-specific evaluations should include, at minimum, the confirmation of disease activity status; the quantification of proteinuria and renal function; blood pressure assessment; antiphospholipid antibody profiling; anti-Ro/SSA and anti-La/SSB testing; medication review; and the targeted evaluation of organ systems that materially alter pregnancy risk, particularly the kidneys, cardiovascular system and lungs. Echocardiography is appropriate when pulmonary hypertension, cardiomyopathy, significant valvular disease, or prior cardiopulmonary symptoms are suspected. Pulmonary function testing or thoracic imaging should be reserved for women with respiratory symptoms or known parenchymal disease rather than performed indiscriminately in all patients. Likewise, thrombophilia-oriented planning should focus primarily on APS rather than broad nonselective testing (5,7,8,16).

Baseline complement levels and anti-dsDNA titers are particularly valuable as serial interpretation during pregnancy is more informative than isolated absolute values. Similarly, documenting preconception serum creatinine, urine protein excretion and urinary sediment markedly improves later differentiation between quiescent renal disease, lupus nephritis flare and superimposed preeclampsia. For women with thyroid symptoms, prior thyroid disease, or autoimmune clustering, thyroid function testing is reasonable; however, thyroid studies should be presented as selective adjuncts rather than mandatory lupus-specific pregnancy biomarkers in all patients. This distinction improves conceptual clarity and aligns the evaluation with practical clinical decision-making (8,16,21). Establishing a comprehensive maternal baseline through targeted laboratory and clinical evaluation is essential for distinguishing physiological gestational changes from pathological processes such as lupus flare, nephritis, or preeclampsia (Table II).

Contraception is relevant in patients with SLE as it underpins safe pregnancy planning. Women with active disease, recent flares, severe organ involvement, or current exposure to teratogenic medications should be protected from unplanned conception until disease control and medication transition have been achieved. Accordingly, contraceptive counseling should be framed as a component of reproductive safety and timing rather than as a disconnected gynecologic topic (8,23).

Highly effective contraception is particularly important for women taking mycophenolate, methotrexate, cyclophosphamide, or other agents that may cause embryotoxicity or fetotoxicity. Intrauterine devices, including copper and levonorgestrel systems, are generally preferred due to their high efficacy and minimal dependence on adherence, although the thrombotic profile and antiphospholipid antibody status should be considered when estrogen-containing methods are discussed. Combined oral contraceptives may be acceptable in selected women with stable, low-activity disease and without antiphospholipid antibodies or a major risk of thrombosis, whereas progestin-only options are often preferred when thrombosis risk is a concern (8,16,25).

The essential clinical principle is that every woman of reproductive age with SLE should have a documented reproductive plan: Whether she desires pregnancy now, later, or not at all; whether conception is medically advisable at the present time; and which contraceptive strategy best aligns with her disease activity and medications. This approach prevents high-risk pregnancies during periods of medical instability and directly supports the goal of well-timed conception (23).

Fertility in women with SLE is often described as broadly preserved; yet, this statement may be misleading in clinical practice. Subfertility in SLE may arise from disease-related inflammation, chronic organ dysfunction, reduced ovarian reserve, associated autoimmune endocrinopathies, sexual dysfunction, psychosocial burden, delayed childbearing and treatment-related gonadotoxicity. Therefore, the infertility discussion should extend beyond the mere observation that infertility ‘is not uncommon’ and instead outline a diagnostic and management framework tailored to lupus (15,26-28).

The initial evaluation should mirror standard infertility work-up, but with SLE-specific expansion. Core assessment includes ovulatory history, ovarian reserve testing with anti-Mullerian hormone and/or antral follicle count, thyroid assessment when indicated, a review of menstrual function, age-related fertility risk, partner-related factors and medication exposure. Particular attention should be paid to cumulative cyclophosphamide exposure, as gonadal toxicity is dose- and age-dependent and remains one of the most critical iatrogenic threats to fertility in SLE. Recent data support the use of anti-Mullerian hormone and antral follicle count as clinically useful markers of diminished ovarian reserve in this population, even when menstrual cycles appear preserved (27). These markers are particularly useful because cyclophosphamide-related ovarian injury may precede overt menstrual disturbance, and contemporary reviews of fertility in SLE recommend incorporating ovarian reserve testing into individualized reproductive counseling (26,27).

Fertility preservation should be discussed prior to the e of cyclophosphamide whenever feasible. Concurrent gonadotropin-releasing hormone agonists may reduce the risk of ovarian insufficiency and improve the odds of later pregnancy, although they should be viewed as protective rather than fully restorative. When disease severity permits, mycophenolate-based nephritis regimens may reduce gonadotoxic exposure compared with cyclophosphamide; however, this advantage is relevant to long-term reproductive planning and not to pregnancy itself, as mycophenolate is contraindicated during gestation (28). Assisted reproductive technologies may be considered in carefully selected patients with quiescent disease; however, stimulation protocols should be coordinated with rheumatology and maternal-fetal medicine teams because estrogen exposure, thrombosis risk, and antiphospholipid antibodies may alter the safety profile. Anticoagulation and hydroxychloroquine continuation may be necessary in selected patients undergoing assisted reproduction (8,26,29).

The effects of SLE on pregnancy should be discussed in pregnancy-specific terms rather than extrapolated from disease behavior outside gestation. The principal determinants of adverse outcomes are active disease at conception, lupus nephritis (current or previous), antiphospholipid antibodies or antiphospholipid syndrome, chronic hypertension, accumulated organ damage, and anti-Ro/SSA or anti-La/SSB seropositivity. These factors do not confer identical risk throughout gestation; rather, they influence different maternal and placental pathways at different times in pregnancy (4,5,8,16,30).

During the first trimester, active systemic inflammation and antiphospholipid-mediated placental injury increase the risks of implantation failure, miscarriage and early pregnancy loss. In the second and third trimesters, placental malperfusion, endothelial dysfunction, nephritis and maternal vascular disease become increasingly relevant, translating into preeclampsia, fetal growth restriction, medically indicated prematurity, and stillbirth. Anti-Ro/SSA and anti-La/SSB antibodies introduce a distinct fetal risk profile, especially congenital heart block and neonatal lupus, which emerges during the mid-trimester period of greatest transplacental antibody effect (5,8,31-33).

Evidence-based counseling should therefore emphasize timing and stratification. Women who conceive in remission or low disease activity on pregnancy-compatible therapy usually have substantially improved outcomes than those who conceive during active disease or while receiving teratogens. Recent data confirm that active disease, nephritis, and antiphospholipid antibodies are among the most consistent predictors of adverse pregnancy outcomes, while pregnancy planning and medical readiness remain modifiable levers that clinicians can intervene upon before conception (4,17,23,30). This risk pattern is supported by systematic evidence identifying lupus nephritis, antiphospholipid antibody positivity, and active disease as recurrent predictors of fetal loss, preterm birth, hypertensive disease, and fetal growth restriction (4,30).

The puerperium is a high-risk transition period in SLE. Hemodynamic shifts, postpartum inflammatory rebound, medication changes, interrupted follow-up and the risk of thrombosis, particularly in women with antiphospholipid antibodies all contribute to maternal vulnerability. Postpartum care should therefore be prespecified prior to delivery and include thromboprophylaxis duration when indicated, blood pressure follow-up, renal reassessment in women with nephritis or preeclampsia, medication reconciliation for lactation, and early rheumatology review as flares may emerge in the weeks to months following delivery (8,16,44,45).

Pharmacological management for SLE during pregnancy should be presented according to therapeutic intent and reproductive safety rather than as a list of isolated agents. The central objective is to maintain maternal disease quiescence using pregnancy-compatible therapy as uncontrolled lupus is consistently more dangerous to both the mother and fetus than the majority of approved medications used judiciously during gestation. Accordingly, therapy should be stratified into: i) Medications recommended to be continued; ii) medications that can be used when clinically indicated; iii) medications that require discontinuation prior to conception due to known teratogenicity or insufficient safety data (8,9,15).

This section briefly discusses biologics and emerging therapies to reflect current SLE therapeutics. Anifrolumab is currently an approved treatment for moderate-to-severe SLE; some women of reproductive age may present for preconception counseling while receiving it. However, human pregnancy data remain insufficient to recommend routine continuation during gestation; thus, current practice generally favors transition to better-characterized pregnancy-compatible regimens prior to conception whenever disease control allows (61). Belimumab has a growing, yet still incomplete pregnancy safety dataset and may be considered case by case in refractory disease, whereas rituximab is usually reserved for severe maternal indications in exceptional circumstances (9,16). Optimizing pharmacological management in SLE during pregnancy requires balancing maternal disease control with fetal safety through the use of pregnancy-compatible therapies and the avoidance of teratogenic agents (Table III).

Emerging classes such as Janus kinase inhibitors should also be mentioned in the context of reproductive counseling. Although these agents are not standard pregnancy therapies in SLE, they are increasingly encountered in immune-mediated disease management and are generally avoided in pregnancy due to limited human safety evidence. Their relevance to the present review lies in pre-pregnancy medication reconciliation, washout planning, and risk communication rather than use during gestation itself. This distinction improves the completeness and contemporary relevance of the pharmacologic discussion without overstating pregnancy safety data.

Pregnancy in women with SLE currently has a substantially improved prognosis than in earlier decades; however, favorable outcomes depend on one principle above all others: Conception should occur during sustained remission or low disease activity on pregnancy-compatible therapy. Across the current evidence base, the most consistent drivers of adverse outcome are active disease at conception, lupus nephritis, antiphospholipid antibodies/APS, chronic organ damage and inadequate pre-pregnancy optimization. Conversely, hydroxychloroquine continuation, aspirin prophylaxis when appropriate, anticoagulation for APS, and structured multidisciplinary surveillance meaningfully improve care (4-6,8,16,17).

Clinically, pregnancy in patients with SLE should be managed as a longitudinal pathway rather than an isolated gestational episode. This pathway includes reproductive planning and contraception during unsafe periods, rigorous pre-pregnancy assessment, trimester-specific maternal-fetal monitoring, prompt differentiation of flare from obstetric mimics such as preeclampsia, and postpartum follow-up for thrombosis, renal deterioration, hypertension, flares and medication-lactation reconciliation. Remaining knowledge gaps include the optimal role of biomarkers for nephritis vs. preeclampsia discrimination, long-term outcomes following in utero exposure to novel biologics and targeted therapies, and the refinement of individualized fetal surveillance strategies in antibody-positive pregnancies. Future research is warranted to focus on these clinically unresolved areas to support more precise and safer reproductive care for women with SLE.